Technical Assistance Consultant’s Report...1.6 C OST E STIMATE FOR T RANSMISSION L INES..... 15...

Technical Assistance Consultant’s Report

This consultant’s report does not necessarily reflect the views of ADB or the Government concerned, and ADB and the Government cannot be held liable for its contents. All the views expressed herein may not be incorporated into the proposed project’s design.

Project Number: 41450 February 2012

Preparing the Ban Sok–Pleiku Power Transmission Project in the Greater Mekong Subregion (Financed by the Japan Special Fund)

Prepared by

Électricité de France

Paris, France

For Asian Development Bank

BAN SOK – PLEIKU FINAL REPORT 10-02-2012

LAO PDR / VIETNAM

Asian Development Bank

CONSULTANCY SERVICES FOR PREPARING THE

BAN-SOK PLEIKU POWER TRANSMISSION PROJECT 500kV

TA 6481-REG

FINAL REPORT

500kV BANSOK (HATXAN)-PLEIKU

Transmission System

Main Report

LAO PDR / VIETNAM


CONSULTANCY SERVICES FOR PREPARING THE BAN-SOK PLEIKU POWER TRANSMISSION PROJECT 500 kV OHL_TA 6481-REG


TABLE OF CONTENTS

1 EXCECUTIVE SUMMARY.............................................................................................................................................. 1

1.1 PROJECT SCOPE ............................................................................................................................................ 1 1.1.1 Background ......................................................................................................................................... 1 1.1.2 Progress Status of the Feasibility Study ............................................................................................... 1 1.1.3 Challenges to the Implementation of the Feasibility Study ................................................................. 2

1.2 ENVIRONMENT AND SOCIAL FIELD ACTIVITIES..................................................................................................... 3 1.3 ENVIRONMENTAL AND SOCIAL DUE DILIGENCE OF THE ASSOCIATED PROJECTS .......................................................... 4 1.4 PROPOSED ROUTES OF TRANSMISSION LINES ................................................................................................... 14

1.4.1 In Lao PDR ......................................................................................................................................... 14 1.4.2 In Vietnam ......................................................................................................................................... 14

1.5 DESIGN CRITERIA AND SPECIFICATIONS FOR TRANSMISSION LINES ........................................................................ 15 1.6 COST ESTIMATE FOR TRANSMISSION LINES ...................................................................................................... 15

1.6.1 In Lao PDR ......................................................................................................................................... 15 1.6.2 In Vietnam ......................................................................................................................................... 15

1.7 DESIGN CRITERIA FOR SUBSTATIONS ............................................................................................................... 15 1.7.1 In Lao PDR ......................................................................................................................................... 16 1.7.2 In Vietnam ......................................................................................................................................... 16

1.8 COST ESTIMATE FOR SUBSTATION .................................................................................................................. 16 1.8.1 In Lao PDR ......................................................................................................................................... 17 1.8.2 In Vietnam ......................................................................................................................................... 17

1.9 SYSTEM STUDY ........................................................................................................................................... 17 1.9.1 Review of PDP in Lao PDR ................................................................................................................. 17 1.9.2 Review of PDP in Vietnam ................................................................................................................. 18 1.9.3 Review of Greater Mekong Masterplan ............................................................................................ 18 1.9.4 Network Studies ................................................................................................................................ 18 1.9.5 Connection to Vietnam Network ....................................................................................................... 18 1.9.6 Temporary Connection ...................................................................................................................... 19 1.9.7 Network Study Conclusion ................................................................................................................. 19

SECTIONS 1.10 TO 1.12 NOT DISCLOSED AS PER ADB’S PUBLIC COMMUNICATIONS POLICY (PARA 97)

1.13 IMPLEMENTATION SCHEDULE ........................................................................................................................ 20

2 BACKGROUND .......................................................................................................................................................... 21

3 SCOPE OF THE DETAILED FEASIBILITY STUDY ............................................................................................................ 23

3.1 PROGRESS STATUS OF THE FEASIBILITY STUDY .................................................................................................. 23 3.2 INTERIM REPORT (PHASE 1) ......................................................................................................................... 23 3.3 DUE DILIGENCES ........................................................................................................................................ 24 3.4 WORKS ON SITE ......................................................................................................................................... 24 3.5 DRAFT FINAL REPORT .................................................................................................................................. 24 3.6 REVISED TASKS SCHEDULE OF THE TECHNICAL ASSISTANCE ................................................................................. 25

4 ACTIVITY IN THE FIELD .............................................................................................................................................. 26

4.1 ENVIRONMENTAL SPECIALIST FIELD ACTIVITIES ................................................................................................. 26 4.1.1 Laos ................................................................................................................................................... 26 4.1.2 Vietnam ............................................................................................................................................. 26

4.2 SOCIAL SPECIALIST FIELD ACTIVITIES ............................................................................................................... 26 4.2.1 Lao PDR ............................................................................................................................................. 26 4.2.2 Vietnam ............................................................................................................................................. 26

5 ENVIRONMENTAL AND SOCIAL DUE DILIGENCE OF THE ASSOCIATED PROJECTS ....................................................... 28

5.1 GENERAL .................................................................................................................................................. 28 5.2 SUMMARY OF GAPS IDENTIFIED IN THE ENVIRONMENTAL DOCUMENTS OF THE FIVE ASSOCIATED PROJECTS; ................ 28

5.2.1 Xekhaman 1 ....................................................................................................................................... 28 5.2.2 Xanxay ............................................................................................................................................... 29 5.2.3 Xekhaman 4 ....................................................................................................................................... 29 5.2.4 Sekong 3A .......................................................................................................................................... 30

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5.2.5 Sekong 3B .......................................................................................................................................... 30 5.3 SUMMARY OF GAPS IN THE CONSULTANT DOCUMENTATION AND PROPOSALS FOR SIA AND LARAPS FOR ASSOCIATED

PROJECTS ............................................................................................................................................................... 31 5.3.1 All Projects Compliance with ADB and GOL Social Safeguards ......................................................... 31 5.3.2 Xekhaman 1 ....................................................................................................................................... 33 5.3.3 Xanxay ............................................................................................................................................... 34 5.3.4 Xekhaman 4 ....................................................................................................................................... 35 5.3.5 Sekong 3A and 3 B ............................................................................................................................. 35

6 THE PROPOSED ROUTE OF TRANSMISSION LINES ..................................................................................................... 36

6.1 TRANSMISSION LINE IN LAO PDR .................................................................................................................. 36 6.1.1 Map with different proposed routes ................................................................................................. 36 6.1.2 Technical Constraints ........................................................................................................................ 37 6.1.3 Environmental Impacts ..................................................................................................................... 38 6.1.4 Social Impacts .................................................................................................................................... 45 6.1.5 Preferred route in Lao PDR ................................................................................................................ 46

6.2 HATXAN SUBSTATION (LAO PDR) .................................................................................................................. 48 6.2.1 Environmental considerations ........................................................................................................... 48 6.2.2 Social Considerations......................................................................................................................... 49 6.2.3 Technical Constraints ........................................................................................................................ 49

6.3 TRANSMISSION LINE IN VIETNAM ................................................................................................................... 50 6.3.1 Environmental Impacts ..................................................................................................................... 50 6.3.2 Social Impacts .................................................................................................................................... 50 6.3.3 Technical Constraints ........................................................................................................................ 51 6.3.4 Preferred Route in Vietnam ............................................................................................................... 53 6.3.5 Delivery Point .................................................................................................................................... 54

6.4 PLEIKU SUBSTATION (VIETNAM) .................................................................................................................... 56 6.4.1 Connection in 500kV .......................................................................................................................... 56 6.4.2 Connection in 220kV .......................................................................................................................... 56

7 DESIGN CRITERIA & SPECIFICATIONS FOR TRANSMISSION LINE ................................................................................ 57

7.1 GENERAL COMMENT ................................................................................................................................... 57 7.2 BIDDING CONFIGURATION IN BOTH COUNTRIES ................................................................................................ 57

7.2.1 Level of Design for Bidding Purpose in LAO PDR ............................................................................... 58 7.2.2 Level of Design for Bidding Purpose in Vietnam ................................................................................ 59

7.3 TECHNICAL DESIGN CRITERIA ........................................................................................................................ 60 7.3.1 General Geometrical Design Criteria for Both Countries ................................................................... 60

7.4 DESIGN CRITERIA FOR TRANSMISSION LINE IN LAO PDR ..................................................................................... 61 7.4.1 General .............................................................................................................................................. 61 7.4.2 Electrical Design ................................................................................................................................ 61 7.4.3 Mechanical Design ............................................................................................................................ 62 7.4.4 Towers ............................................................................................................................................... 63 7.4.5 Conductors ........................................................................................................................................ 63 7.4.6 Earth Wires ........................................................................................................................................ 64 7.4.7 Foundations ....................................................................................................................................... 65 7.4.8 Hardware and Fittings ....................................................................................................................... 65 7.4.9 Communication System ..................................................................................................................... 65 7.4.10 UXO/Mines Risks Assessment ....................................................................................................... 66

7.5 DESIGN CRITERIA FOR TRANSMISSION LINE IN VIETNAM ..................................................................................... 66 7.5.1 General .............................................................................................................................................. 66 7.5.2 Electrical Design ................................................................................................................................ 67 7.5.3 Mechanical Design ............................................................................................................................ 67 7.5.4 Towers ............................................................................................................................................... 68 7.5.5 Conductors ........................................................................................................................................ 69 7.5.6 Earth Wires ........................................................................................................................................ 69 7.5.7 Foundations ....................................................................................................................................... 70 7.5.8 Hardware and Fittings ....................................................................................................................... 70 7.5.9 Communication System ..................................................................................................................... 70 7.5.10 UXO/mines risks assessment ........................................................................................................ 70

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8 COST ESTIMATE FOR TRANSMISSION LINE ................................................................................................................ 71

8.1 COST ESTIMATE FOR TRANSMISSION LINE IN LAO PDR ...................................................................................... 71 8.1.1 Environmental Mitigation and Monitoring ....................................................................................... 71 8.1.2 Construction Cost Details .................................................................................................................. 71 8.1.3 O&M costs in Lao PDR ....................................................................................................................... 71

8.2 COST ESTIMATE FOR TRANSMISSION LINE IN VIETNAM ....................................................................................... 72 8.2.1 Environmental Mitigation and Monitoring ....................................................................................... 72 8.2.2 Construction Cost Details .................................................................................................................. 72

8.3 COMMENTS ON THE TRANSMISSION LINE COSTS ............................................................................................... 72 8.3.1 Difference between Lao PDR and Vietnam........................................................................................ 72 8.3.2 Technical Option ................................................................................................................................ 73

9 DESIGN CRITERIA & SPECIFICATIONS FOR SUBSTATIONS .......................................................................................... 74

9.1 DESIGN CRITERIA FOR HATXAN SUBSTATION .................................................................................................... 74 9.1.1 General .............................................................................................................................................. 74 9.1.2 Standards .......................................................................................................................................... 74 9.1.3 Electrical Design ................................................................................................................................ 75 9.1.4 Mechanical Design ............................................................................................................................ 76 9.1.5 Structure ............................................................................................................................................ 77 9.1.6 Busbar ............................................................................................................................................... 78 9.1.7 Circuit Breakers ................................................................................................................................. 80 9.1.8 Transformers ..................................................................................................................................... 81 9.1.9 Auxiliaries .......................................................................................................................................... 83 9.1.10 Civil Works .................................................................................................................................... 83 9.1.11 Protection Policy ........................................................................................................................... 86 9.1.12 Telecommunication ....................................................................................................................... 88 9.1.13 Hatxan S/S Single line Diagram..................................................................................................... 89 9.1.14 Hatxan S/S Layout (Phase 1) ......................................................................................................... 90 9.1.15 Hatxan S/S Layout (Phase 2) or Final Phase .................................................................................. 91

9.2 DESIGN CRITERIA & SPECIFICATION FOR PLEIKU SUBSTATION EXTENSION .............................................................. 92 9.2.1 General .............................................................................................................................................. 92 9.2.2 Electrical Design ................................................................................................................................ 92 9.2.3 Mechanical Design ............................................................................................................................ 93 9.2.4 Structure ............................................................................................................................................ 94 9.2.5 Busbar ............................................................................................................................................... 95 9.2.6 Circuit Breakers ................................................................................................................................. 96 9.2.7 Auxiliaries .......................................................................................................................................... 97 9.2.8 Civil Works ......................................................................................................................................... 97 9.2.9 Protection Policy ................................................................................................................................ 99 9.2.10 Telecommunication ..................................................................................................................... 102 9.2.11 Underground Cables ................................................................................................................... 103 9.2.12 Bays permutation ........................................................................................................................ 105 9.2.13 Pleiku S/S Single line Diagram..................................................................................................... 107 9.2.14 Pleiku S/S Layout ......................................................................................................................... 108 9.2.15 Pleiku S/S in Case of Temporary Interconnection in 230/220 kV ................................................ 109

10 COST ESTIMATE FOR SUBSTATIONS ........................................................................................................................ 110

10.1 COST ESTIMATE FOR HATXAN SUBSTATION .................................................................................................... 110 10.1.1 Option 1: Double BB Configuration with 3 AT 600MVA Full Scheme .......................................... 110 10.1.2 Option 2: Double BB Configuration with 3 AT 600MVA in case Xekaman 2 & 2A not connected 111 10.1.3 Option 3: Double BB Configuration with 2 AT 600MVA in case XEKAMAN 2 & 2A and 4 & 4A not connected 112 10.1.4 Cost of Hatxan 230/115kV .......................................................................................................... 113 10.1.5 Cost Estimate for O&M of Hatxan Substation ............................................................................ 113

10.2 COST ESTIMATE FOR EXTENSION OF PLEIKU SUBSTATION .................................................................................. 113 10.2.1 Option 1: Overhead Line Connection .......................................................................................... 113 10.2.2 Option 2: Underground Cable Connection .................................................................................. 113 10.2.3 Option 3: with bays permutation at Pleiku S/S ........................................................................... 113

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10.2.4 Temporary Configuration with Hatxan to Pleiku in 230/220kV – Additional Cost at Both Substations ................................................................................................................................................... 114

10.3 COMMENTS ON THE COSTS ......................................................................................................................... 114

11 SYSTEM STUDY ....................................................................................................................................................... 115

11.1 INITIAL CONNECTION ................................................................................................................................. 115 11.1.1 On Vietnamese side .................................................................................................................... 115 11.1.2 On Lao side .................................................................................................................................. 115

11.2 REVIEW OF PDP IN VIETNAM ...................................................................................................................... 115 11.3 REVIEW OF PDP IN LAO PDR ..................................................................................................................... 118 11.4 THE GREAT MEKONG SUBREGION MASTER PLAN ........................................................................................... 123 11.5 CONCLUSIONS ON THE PDP OF BOTH COUNTRIES AND THE GREATER MEKONG MASTER PLAN ................................ 124

11.5.1 Great Mekong Master Plan ......................................................................................................... 124 11.5.2 Laotian PDP ................................................................................................................................. 125 11.5.3 Vietnamese PDP ......................................................................................................................... 125

11.6 SUMMARY OF HYDRO PROJECTS .................................................................................................................. 125 11.7 CURRENT STUDIES FOR CONNECTING HATXAN S/S TO THE VIETNAMESE SYSTEM .................................................. 125

11.7.1 Static Results ............................................................................................................................... 133 11.7.2 Dynamic Results .......................................................................................................................... 134 11.7.3 Temporary Connection ................................................................................................................ 135

11.8 CONCLUSIONS .......................................................................................................................................... 136

CHAPTERS 12 TO 14 ARE NOT DISCLOSED AS PER ADB'S PUBLIC COMMUNICATION POLICY 2011 (PARA 97).

15 PROCUREMENT AND IMPLEMENTATION SCHEDULE ............................................... ERROR! BOOKMARK NOT DEFINED.

15.1 GENERAL IMPLEMENTATION SCHEDULE ................................................................ERROR! BOOKMARK NOT DEFINED.

LIST OF ANNEXES ............................................................................................................................................................. 138

ANNEXES 1, 2, 4, AND 5 ARE NOT DISCLOSED AS PER ADB'S PUBLIC COMMUNICATION POLICY 2011 (PARA 97).

VOLUME 3 LAO PDR STUDIES ........................................................................................................................................... 138

ANNEX 3.1 – TL & S/S IEE IN LAO PDR ...................................................................................................... 138 ANNEX 3.2 – TL & S/S LARAP AND RESETTLEMENT POLICY FRAMEWORK IN LAO PDR .......................... 138

VOLUME 6 VIETNAM STUDIES ......................................................................................................................................... 138

ANNEX 6.1 – TL & S/S IEE IN VIETNAM ........................................................................................................ 138 ANNEX 6.2 – TL & S/S LARAP IN VIETNAM ................................................................................................. 138

VOLUME 7 DUE DILIGENCE REPORT ................................................................................................................................. 138

ANNEX 7.1 – SUMMARY OF STATUS OF ASSOCIATED PROJECT END OF 2011 ........................................... 138 ANNEX 7.2 – ENVIRONMENTAL DUE DILIGENCE ON THE ASSOCIATED ......................................................... 138 ANNEX 7.3 – SOCIAL DUE DILIGENCE ON THE ASSOCIATED PROJECTS ...................................................... 138 ANNEX 7.4 –FINANCIAL AND ECONOMIC CALCULATION TABLES ................................................................... 138

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LIST OF ABBREVIATIONS USED IN THE REPORT

AC : Alternative Current

ADB : Asian Development Bank

AIS : Air Isolative Switchgear

APs : Affected Person or People

BOT : Built Own Transfer

CB : Circuit Breaker

CHADs : Central and Provincial Health Authorities

CSCS : Computerized Substation Control System

COD : Commissioning Operation Date

DC : Domestic Currency

DD : Due Diligence

DEM Department of Energy and Mines

DOE : Department of Electricity in MIH

EDF : Electricité de France

EDL : Electricité du Lao

EGAT : Electricity Generating Public Company Limited

EHV : Extra High Voltage

EIA : Environmental Impact Assessment

EMP : Environmental Management Plan

EMU : Environment Management Unit

EOD : Explosive Ordnance Disposal

EPC Engineering Procurement Construction

EPDP : Ethnic Peoples' Development Plan

ESD : Environment and Social Department

ESIA : Environment and Social Impact Assessment

ESL : Earth Systems Lao

LAO PDR / VIETNAM





EVN : Vietnam Electricity

EVN/NPT : National Power Transmission Corporation

GDP : Gross Domestic Product

GDP : Gender Development Plan

GMS : Greater Mekong Sub-Region

GoL : Government of Lao PDR

HV : High Voltage

IEC : International Electrotechnical Commission

IEE : Initial Environment Examination

IMAS : International Mine Action Standards

IOE Institute of Energy

IOL : Inventory of Losses

IPDP : Indigenous Peoples Development Plan

IPP : Independent Power Producer

Lao PDR : Lao People’s Democratic Republic

LARAP : Land Acquisition and Resettlement Action Plan

LV : Low Voltage

MCH : Maternal 2 Child Health

MEM : Ministry of Energy and Mines

MOIT Ministry of Industry and Trade

NBCA : National Bio-diversity and Conservation Area

NGO : Non Governmental Organisation

NPA : National Protected Area

O&M : Operation & Maintenance

OHGW : Over Head Ground Wire

OLTC : On Load Tap Changer

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OPGW : Optical Ground Wire

PDP Power System Development Plan

PECC4 : Power Engineering Consulting Joint Stock Company 4 (Vietnamese local consultant)

PMU Project Management Unit

PPA Power Purchase Agreement

PRC : People Republic of China

PSIA : Poverty and Social Impact Assessment

RAP : Resettlement Action Plan

ROW : Right of Way

RP : Resettlement Plan

SES Social Economic Survey

S/S : Sub Station

SCADA : Supervisory Control and Data Acquisition

SEIA : Summary Environmental Impact Assessment

SIA : Social Impact Assessment

TA : Technical Assistance

TEPCO : Tokyo Electric Power Company

TL : Transmission Line

ToC : Table of Contents

ToR : Terms of Reference

TPO : Transmission Project Owner

TSO : Transmission System Operator

TPP : Thermal Power Plant

UXO : Unexploded Ordnance

VLPC : Viet-Lao Power Joint Stock Company

WREA : Water Resources and Environment Administration

LAO PDR / VIETNAM



BAN SOK – PLEIKU FINAL REPORT 10-02-2012 Page 1 of 208

1 EXCECUTIVE SUMMARY

1.1 PROJECT SCOPE

1.1.1 Background

The Feasibility Study will be carried out in close coordination with Electricité du Laos (EdL), Electricité du Vietnam (EVN) and independent power producers (IPPs) that will be involved in the hydropower development in southern Laos. The Ban Sok (Hatxan) Substation in Lao PDR will be the connection point between the Laos-Vietnam interconnection that has to meet the Vietnamese technical standards, and the future Laos-Thailand interconnection that will have to meet the Thai technical standards. Therefore, the compatibility of having the Vietnam and Thailand power grid systems synchronously interconnected through the Lao PDR territory will be checked. To date, the technical decision to connect both circuits of the 500kV Transmission Line to Pleiku S/S has been officially taken according to the Masterplan 7 which was submitted in September 2011. The name of Bansok substation (S/S) has been changed to Hatxan, however the final location of Hatxan S/S has just changed due to an Airport Project. The final location and the size of the land are now finalized. According to Xekaman 1 Power Company, the construction of Xehaman 1 has already started and 15% of works were completed as of November 2011. However according to the visit to the site in September 2010, this progress of works seems to be very pessimistic, and the correct value should be around 30%.

1.1.2 Progress Status of the Feasibility Study

In May 2009 the consultant was instructed by ADB to stop work as the project was to be suspended due to on-going issues with both governments involved. An official letter of suspension was received in June 2009. As a result the work was not re-initiated until May 2010. This Draft Final Report, therefore records the findings since 2009, as well as the new works done after the TA was reactivated. A summary of DD of E&S impact for the different IPP is included in this report, however the separate DD reports were provided earlier in 2011, and the final versions of the DD are included in annexes of this Final Report. Design criteria, specifications and drawings, both for Lao PDR and Vietnam are presented for TL and S/S. Some differences between standards are pointed out. The main point is that there is no technical problem, only from financial point of view, and the technical specifications will not have the same impact on the construction costs. Only the Lao PDR technical documents are ready for bidding, as it is EPC configuration, nevertheless drawings and specifications are also provided, however they could not be used for the type of bidding process in Vietnam. An assessment of the wheeling charges with the new scenarios has been implemented. In particular the IRR was increased to 10% and extended over 35 years. For this the estimated

LAO PDR / VIETNAM




cost of the project was calculated for several options. The wheeling charges cover only the 500kV transmission lines to be constructed in Lao PDR, and the switchyard 230/500kV in Hatxan S/S. For the remaining activities related to E&S impacts of the 500kV in Laos and in Vietnam, the ADB’s Consultant was facing some budgeting issues, namely: Environmental assessment in Lao PDR: The budget allocated in the ADB TA was adequate for an ADB-style IEE but not a full EIA as defined by Lao PDR’s new environmental assessment law and requested by its Water Resources and Environment Administration (WREA). An interim and incomplete IEE was prepared and submitted to ADB as proof that the full EIA was not necessary and as a document to use in reaching a compromise with Lao PDR. These negotiations are still pending, although LaoPDR has again indicated that a full EIA is required. Nevertheless ADB has stated a budget for an EIA would be available, however the task would be subject to a separate TA. LARAP in Vietnam: A LARAP survey was undertaken by PECC4 prior to implementation of the TA. The data from this survey has been reviewed, and incorporated into a draft LARAP for the TL. The data from this survey were reviewed, and incorporated into a draft LARAP for the TL.

1.1.3 Challenges to the Implementation of the Feasibility Study

Between the initial phase of the feasibility study (2009) and the remobilization (2010), the requirements for environmental and social safeguards in Lao PDR changed with the implementation of the new Decree on Environmental and Social Impact Assessment (2010). The repercussions of this change were that the previously acceptable method of undertaking an Initial Environmental Examination (IEE) for the transmission line (as required by the ADB safeguard policies and the basis of the ToR for this TA) is no longer acceptable under Lao Legislation. The new Decree (and supporting documents) requires a full EIA for the Hatxan-Pleiku transmission line and Substation project. The TA project does not qualify under the grandfather clause in the 2010 Decree since it did not have an approved ToR prior to the new decree coming into force. As a result of this change, (WREA) did not allowed consultations to take place for the IEE, rendering it an incomplete draft until consultation can be undertaken. Difficulties with the IEE in Vietnam were encountered due to an uncertain RoW width, 70 meters in Lao PDR, and 32 meters in Vietnam. The RoW width identified by EVN (and assessed by PECC4 in the draft IEE and IOL studies) is significantly less than international standard, and approximately half of that required in Lao PDR. This discrepancy has been brought to the attention of EVN and PECC4, and the Final IEE document for Vietnam will consider this larger (international standard) RoW. The width in Vietnam which is very narrow in comparison with the current best practices all over the world, and which is not compatible in forest area with the safe clearance of vegetation, will have to be confirmed by EVN/NPT before the end of the site survey activities1.

1 An uncertain RoW width had significant implications for the IEE since in order to meet international standards EVN will need to more than double its RoW and effectively doubling the corridor of impact, something that will need to be reflected in the final IEE and LARAP documentation.

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It is difficult to implement the design of Hatxan substation, firstly due to the permanent change of the PDP of Lao PDR and associated changes to the switchyard design. Secondly, the location of the substation is an issue. While moving the substation to a new location has been validated, the new land has some drawbacks for switchyard construction such as creeks and hilly terrain. Furthermore, the additional land was requested to the Ministry of Mines, and is still pending approval. The Masterplan 7 in Vietnam is now approved, the scenario assessed in this report and the associated draft design specifications and drawings refer to a connection of 2 x 500kV from Hatxan to Pleiku S/S. The route in Lao PDR was finalized, showing future difficulties of construction for the section inside the NPA, close to the Border with Vietnam. In addition the Delivery Point was also validated by all the parties. Unfortunately its access is not easy, and it is located on a top of mountain at 1020m altitude, which is the highest point of the TL along its complete route in Vietnam and Lao PDR. The preparation of bidding documents is not easy on the Vietnam site, firstly because they do not use an EPC process, and secondly because, based on current practices, it is the role of the Consultant to implement the whole design of facilities, and thus the design included in the bidding documents is very detailed, and would require one year of preparation from the current date. This delay does not affect the global schedule of construction, however ADB has to define the role of the TA’s Consultant in that case. The organisation of the TPO and the contents of the existing PPA for Xekaman 1 show several difficulties to be re solved before the COD of the first IPP.

1.2 ENVIRONMENT AND SOCIAL FIELD ACTIVITIES

Both Environmental and Social teams implemented field activities necessary for the works included in the TA. In Laos, five hydro project sites were visited, i.e. Xekaman 1, Xekaman 4, Xekong 3a and 3b, and Xanxay. These visits were necessary to complete the Due Diligence audits to establish compliance of these projects with both ADB and Lao PDR safeguards requirements. Specific project safeguard materials prepared were a LARAP and Social Impact Assessment (SIA) for Lao PDR and Vietnam as well as IEEs2 for Transmission Line corridor and Substations in both countries. This work involved several field surveys in both countries. In Lao PDR, alternative alignments for the TL were scrutinized in order to identify the best route. In Vietnam, the route of the line proposed by the Vietnamese counterpart PECC4 was investigated, in order to validate the alignment chosen, and prepare the IEE and LARAP for the Vietnam side3.

2 As indicated in the previous section, the Lao environmental safeguard documentation remains incomplete since Lao PDR’s WREA has specified the need for a full Lao PDR-style EIA as per Decree 120 (2010). ADB has classified this project as needing only an IEE and as such allocated funds to complete only this work and not the much more detailed EIA. At present, ADB and WREA are negotiating a way forward, but until that time, the IEE remains incomplete.

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1.3 ENVIRONMENTAL AND SOCIAL DUE DILIGENCE OF THE ASSOCIATED

PROJECTS

Of the 7 projects requiring a DD audit (as determined by the ADB’s definition of ‘associated projects’), only five were found to have at least some basic documentation. Dak Emeule and Xekhaman 2 could not be examined as no safeguard documentation has been completed for either project. The Due Diligence report, providing a detailed assessment of each project’s compliance with environmental and social safeguards has been prepared and submitted to ADB and both governments in March 2011. None of the five project’s E&S documentation audited was in compliance with ADB or Lao PDR Environmental and Social safeguard specifications (see Chapter 5). Measures to address these gaps are listed in Chapter 5. During Nov. 2011 meetings with the Vietnamese consultants, discussion concerning Xekhaman 4A and 4B projects was introduced for the first time. Until this meeting there had been no mention of XK 4A and 4B. There was only a Xehkaman 4 which consists of two dams; a single larger reservoir and two penstocks supplying water to one powerhouse. The Vietnamese’ IEE reviewed by the consultant only contained information for XK4. One of two maps, not included in the IEE (see Annex Vol. 7) showed a XK4B located 20-30 km downstream from XK4 (no XK4A), a totally different project—but nevertheless showing a connection to the Ban Sok substation. This raises the issue of a further project in this environmental and biodiversity “hotspot” for which no detailed assessment has been completed. The E&S Summary Statement of the associated projects, on November 2011, is as follows: Summary Statement: Key Environmental and Social Aspects Introduction 1. The purpose of this statement is to summarise the current status of key environmental and

social aspects relevant to the Ban Hatxan (Ban Sok) – Pleiku 500 kVA transmission line project.

Status of Environmental Safeguard Requirements for 500 kVA Transmission Line 2. As per the TOR for the TA, two (2) Initial Environmental Examinations (IEE) have been

prepared – one for the section of the line in Vietnam and one for the sections of the line and sub-station in Lao PDR.

3. The IEE for the Vietnam section of the line is complete, and has been approved by EVN. 4. The IEE for the section of the line in Lao PDR and the sub-station is currently incomplete, as

public consultation and disclosure requirements have not yet been met. Electricite du Laos 3Prior to the start of the TA, PECC4, the consultant working on behalf of the Vietnam government has prepared a Vietnam-style IEE in 2007, for an alignment and substation configuration different from the present design. This draft IEE was provided to the international consultant in early 2010 and found to be significantly non compliant. Instructions for bringing the document into compliance were prepared in March 2010 and provided to PECC4.

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(EDL) and the Provincial Government refused to permit the consultant to undertake consultation since, with the passing of new EIA legislation in 2010, the transmission line and sub-station were both classified as requiring a full EIA (i.e. two separate full EIA reports). WREA also provided comment on the IEE on the 9th November 2011, which indicated that a full EIA is required. This issue has been raised and discussed at all of the tripartite meetings, and it is the understanding of the consultant that, at the last tripartite meeting, the ADB agreed to fund a full EIA (as a separate project – not included in this TA).

Status of Social / Resettlement Safeguard Requirements for 500 kVA Transmission Line 5. Separate Land Acquisition and Resettlement Action Plans (LARAPs) have been prepared for

the sections of the line in Vietnam and the section of the line and sub-station in Lao PDR. Both LARAPs are complete.

6. In the LARAP for the section of the line in Vietnam, affected household and land estimates

are based on a Right of Way (ROW) of 30.6 m, which is roughly half the internationally recommended ROW (which is also the ROW that will be used in the Lao PDR) of 70 m.

Due Diligence of Associated Projects 7. The project TOR included the requirement for the consultant to complete the safeguard due

diligence audits on all projects which would use the SS and TL, and which had any safeguard documentation available. Of the six (6) projects listed in the TOR, five (5) were found to have at least some basic documentation. Dak Emeule Project could not be examined as no safeguard documentation was available. Xekhaman 2, the seventh project that will eventually feed power to the SS-TL complex, was also not reviewed, as no documentation was available.

8. All safeguard documents reviewed were found to be significantly non-compliant. Issues common to all reviewed documents include:

a. Inadequate consultation with /or information to the affected populations;

b. Failure to consider / address cumulative impacts;

c. Little or no consideration of the impact of the transmission lines connecting the plants to the Ban Hatxan Sub-station.

d. Lack of coherent, implementable Environmental Management Plans (EMPs);

e. Lack of any Indigenous Peoples Development Plan / Gender Development Plan;

f. Lack of consideration of in-migration (particularly of the largely Vietnamese workforce);

g. Inadequate or no HIV/AIDS Awareness and Prevention Programme;

h. Failure to conduct any adequate feasibility study for livelihoods and income restoration measures; and

i. Failure to make any provision for the inclusion of a requisite proportion of Lao manpower in construction work forces.

Issues specific to each project are discussed briefly below.

9. The consultant has been informed that safeguard documents for Xekhaman 1, Xekhaman 4

and Xekong 3 Upper and Lower have been updated since the Due Diligence Review. These updated documents have not been provided to the Consultant for review, but it is highly

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unlikely (given the short period of time between the submission of the Due Diligence Report and the availability of the updated documents) that these updated documents will have addressed the major issues and non-compliances identified in the due diligence review.

Xekhaman 1 / Xanxay 10. The Due Diligence Review found the environmental and social safeguard documents (EIA

and EMP) for the Xekhaman / Xanxay Projects to be significantly non-compliant with ADB and Government of Lao PDR standards. Key issues include:

a. Under Lao PDR regulations and in accordance with international standards, the 32.5 MW Xanxay Project should have its own EIA. The Xekhaman EIA says very little about Xanxay.

b. The EIA missed or downplayed key impacts such as long term water quality , impact on fisheries, loss >6000 ha of NPA land, health impacts associated with tropical reservoirs.

c. The EIA provided only a limited record of the consultations completed, most appearing to be with officials. The level of public consultation and disclosure with affected persons was deemed unacceptable in view of international best practices, ADB safeguard requirements and Lao PDR statutory requirements.

d. No provision is made for the impact of the 3,000 Vietnamese work force or the 12,000 plus accompanying families and service supply traders and workers anticipated in the RAP, or for the Province-wide measures which this and the work forces of other hydropower and related projects will require.

e. No adequate STD/HIV/AIDS awareness and prevention programme is planned for or provided to meet the impact of the incoming work force on the host population;

f. Although the project has a >120 page Environmental Management Plan, as well as a large (several million dollars) mitigation and monitoring budget, the field visit indicated that not a single measure had been implemented thus far – even though construction was 30% complete.

Xekhaman 4 A-B 11. This project is in a highly sensitive environment (pristine broadleaf evergreen jungle),

including Asian Tiger habitat, and only little (if any) field work has been done. 12. There has been no outside / independent review of the EIA documents (as these were not

available during the due diligence review). Xekong 3 Upper and Lower (or 3 A and B)

13. The two EIAs for these projects were virtually the same – with some name changes.

Significant generic information is provided, though very little useful, site specific information.

14. In both EIAs, major impacts are downplayed and dismissed through the use of unsubstantiated statements.

15. No EMPs are provided and there is no record of any consultation being undertaken.

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16. Both EIAs reference the transfer of water (~40 m3/s – approximately half of dry season flows) out of the Xekong Basin to power plants in Vietnam. There is no discussion of the impact of this diversion scheme.

17. No provision is made for the impact of the 3,000 Vietnamese work force or the 12,000 plus accompanying families and service supply traders and workers in each of the two projects, anticipated in the RAP, or for the Province-wide measures which this and the work forces of other hydropower and related projects will require.

18. No adequate STD/HIV/AIDS awareness and prevention programme is planned for or provided to meet the impact of the incoming work force on the host population;

Other Issues 19. There is only limited technical capacity within WREA at the provincial and district levels,

which are responsible for monitoring project compliance and for implementing any measures that are the responsibility of GOL. Attapeu WREA does not have adequate transportation to get to project sites, proper monitoring equipment and does not have adequate human resources to fulfil its responsibilities. Provincial WREA is also kept totally in the dark about activities of the Vietnamese consultants and surveyors working on dam issues; therefore they cannot carry out any real compliance monitoring or enforcement. In Vientiane, there is also a shortfall of staff, given the large number of hydro projects.

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Xekhaman 4 map as included in IEE document

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Xekhaman 4 showing a Xekhaman 4A downstream: From Sept 2009 IEE

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GAP ANALYSIS OF STATUS OF ENVIRONMENTAL AND SOCIAL SAFEGUARDS RELATED TO BAN SOK-PLEIKU TRANSMISSION LINE ADB RETA

No. Project Status Date Future Action Needed

ENVIRONMENTAL SAFEGUARDS

1 Bansok-Pleiku TL Environmental Assessment

1.1 Vietnam side IEE Completed and accepted by MONRE and DONREs Sept. 2011

1.2 Lao IEE Not approved. Due to change in law, full EIA required. Nov. 2011 note indicated that full EIA was needed. Existing document is missing consultation and detailed studies required as part of revised Lao EIA process

Nov. 2011 ADB to provide funds to complete full EIA

Substation Lao’s new decree classifies a substation of the size to be built at Ban Sok as needing its own full EIA. This change in the law occurred after this TA was planned, therefore not budgeted.

n/a WREA needs to decide if this is in or out. If in, then funding should be provided by ADB to complete this additional assessment.

2 Due Diligence of Associated Projects

2.1 Xekhaman 1 Project 30% complete and no mitigation or monitoring measures applied. Pollution damage if increasing. No compliance monitoring undertaken by WREA.

No environmental assessment of the >30km long new road or for the transmission line linking the power station to Ban Sok substation.

Oct. 2011 Non-compliant in terms of EMP implementation, and very substandard consultation program—not documented. Contractor and owner needs to Prepare an EMP action plan from EMP found in the EIA document. Secondly, to begin to implement major mitigation and monitoring ,, measures and repair damage done, e.g. sewage and garbage disposal for >2000 people work camps, etc.

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2.2 Xanxay This hydropower project downstream of Xekhaman 1 is considered a large project and under Lao law requires its own EIA. No such EIA has been undertaken, or to our knowledge even initiated. In fact only a few lines in the Xekhaman 1 EIA refer to Xanxay; therefore it is a large dam project without any safeguards.

Nov.2011 Either WREA needs to declare that Xanxay does not need an EIA or one should be completed (including social safeguard documents).

2.3 Xekhaman 4 An EIA according to Vietnamese regulations is now under preparation in Lao (has not been confirmed. This is fully non-compliant, since Lao requires a complex process starting with an EIA framework which must be approved before the EIA can go ahead, as well as a comprehensive set of consultations . Given the greenfield-nature of this project and the highly sensitive environmental setting, requiring comprehensive field work, there is a very strong likelihood that no such work is being done or nearing completion.

Xekhaman 4 is a complex project consisting of two dams, two long tunnels as well as >140 km if new access road and a long transmission line. None of these elements were mentioned in the IEE. Further there was no mention of a XK4A and 4B, other than on one of the maps which shows a XK4A downstream of XK4, and as a 97MW plant.

Sept. 2011 As of Nov. 25, this project remains fully non-compliant and has no environmental safeguards in place, and no approval by WREA to proceed to a full EIA. There has been no international examination of the progress, other than the original IEE completed in 2010. The IEE was judged to be non-compliant, as it lacked an EMP, consultation and any field survey.

It would appear that there is now a new project, XK4A added to the mix.

This project is in an environmental hotspot, with critically endangered species habitat planned to be inundated, etc. and no solid EIA seems to be underway.

2.4 Xekong 3A and Xekong 3B

These are non-compliant EIA that have not received WREA approval. These are two distinct >300MW dam projects located on the Xekong River in Xekong and Attapeu Provinces. The two EIAs evaluation, were considered non-compliant since their EMPs were incomplete and elements scattered throughout the EIA. The EIA for Xekong3B was consisted of exactly the same text as for Xekong 3A except for the reference to Xekong 3B instead of 3A. Neither of these EIAs are even marginally compliant with ADB.

Sept. 2011 WREA needs to review and comment on these EIAs. Secondly the Vietnamese consultant needs assistance to bring this work into compliance, and use it to implement mitigate and monitoring measures.

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2.5 Dak Emeule No report of any kind is available Nov. 2011 EIA needs to be completed

SOCIAL SAFEGUARDS

3 Ban Sok-Pleiku LARAP

3.1 Vietnam side LARAP

Completed and accepted by MONRE Sept. 2011 The LARAP estimates are based on a Right of Way (ROW) of 30.6 m, which is roughly half the internationally recommended ROW of 70 m a ROW.

3.2 Lao LARAP Completed and accepted by EDL and WREA Sept. 2011

4. Due Diligence-Social Sector

4.1 Xekhaman 1 Inadequate provision for HIV / AIDS prevention among the surrounding population.

Inadequate feasibility study or planning for gender or income restoration of impacted indigenous peoples

Inadequate consultation with or information to the affected populations.

Lack of consideration of in-migration (particularly of the largely Vietnamese workforce);

Failure to conduct any adequate feasibility study for livelihoods and income restoration measures; and

Failure to make any provision for the inclusion of a requisite proportion of Lao manpower in construction work forces

Approve and implement Resettlement Framework as a basis of TA for LARAP implementation;

Public consultation and disclosure needs to be undertaken and documented consistent with Lao Guidelines;

Prepare action plan to implement LARAP and prepare feasible Livelihood Restoration Plans.

Conduct a kick-off workshop for capacity building and coordination of policy, approaches and methodology Vietnamese and Lao agencies.

4.2 Xanxay No social safeguard documents have been prepared for this As above (Either WREA needs to declare that

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Project, and very little is mentioned in the Xekhaman 1 EIA. Xanxay does not need an EIA or one should be completed (including social safeguard documents).)

4.3 Xekhaman 4 No consideration of gender, indigenous peoples or HIV / AIDS.

Inadequate consultation with or information to the affected populations;

Failure to conduct any adequate feasibility study for livelihoods and income restoration measures; and

Failure to make any provision for the inclusion of a requisite proportion of Lao manpower in construction work forces.

EIA measures (as above) should include preparation of social safeguard documents to TOR provided in Resettlement Framework.

4.4 Xekong 3A and 3B RAPs non-compliant with Lao PDR and ADB guidelines.

No consideration of gender, indigenous peoples or HIV / AIDS.

Inadequate consultation with or information to the affected populations.

Lack of consideration of in-migration (particularly of the largely Vietnamese workforce).

WREA needs to review and comment on these RAPs in the context of approval and implementation of the Resettlement Framework and TA.

It is likely that the Vietnamese consultant and / or EDL / Government of Lao will need assistance to bring RAPs into compliance, and then implement measures.

4.5 Dak Emeule No Documentation of any type provided Any EIA undertaken must include social safeguard documents – RAP, social development plan, Indigenous Peoples Develop Plan, etc. prepared under the Resettlement Framework TA.

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1.4 PROPOSED ROUTES OF TRANSMISSION LINES

At this stage the routes are completely finalized as:

The Hatxan substation location is now validated by Lao Authorities and has moved by 10 km due to an airport construction project at km 37-38. However due to significant problems with the configuration of the allocated land, there is a need for further space to facilitate the best implementation of the Hatxan S/S. The final decision in regards to the provision of a complementary area of 10 ha was given by the Lao Authorities, however the configuration of the Haxtun substation is not completely finalised, as on 500kV bus bar the decision of further interconnection is still pending, and the consultant gives its comments on that subject chapter 11, and in the future EDL switchyard, the size of transformers 230/115kV and 115/22kV is given according to the concept design in the Draft Final Report, however EDL will have to adjust according to its real needs in the Southern Area, once their Masterplan is completed. The problem is similar for the outgoing 115kV TL.

The potential impacts of the TL route on Lao PDR side were finalized on site, and in spite of some technical difficulties, overall presents a positive assessment from an E&S point of view as neither dwelling areas nor plantations were identified as crossing the route.

The connection in Vietnam configuration was announced officially, as submitted in the Draft Masterplan 7, namely both lines from Hatxan S/S connected to Pleiku S/S. Only this solution is taken into account in this report.

The Delivery Point at the border was finalized on site, as well as the location of both Dead End Towers. Unfortunately, due to constraints on Vietnamese side, the location of this Delivery Point (DP) is not the best one, as it is located at 1,020m altitude, and will involve overcosts for difficult access. A location close to the road 18A would have been better.

1.4.1 In Lao PDR

Three alternatives, plus the TEPCO proposal were studied since the beginning of the TA. The TEPCO alternative was no longer considered, in spite of the proximity of the road 18A, due to its greater potential impact on the Dong Ampham NPA, as well as the difficult relief in this area with mountains and steep slopes, which would result in increased construction costs. Among the 3 remaining alternatives, Option N° 3 has been retained as preferable route from an E&S and technical point of view. However after the move of Hatxan S/S to km 38-38, the final route follows option 2, as per Fig 2. Whatever the alternative, the routes are located in areas of very high risk in regards to UXO.

1.4.2 In Vietnam

Two alternative alignments were investigated; finally the western one was selected, due to better relief and reduced impact on fixed assets. There is no particular problem of access or effects in sensitive areas such as NPA since the preferred route was planned to bypass these areas. However both routes intersected several agricultural fields, and are in the vicinity of housing. While no detailed UXO map was available, according to Fig 7, it is likely that one part of the TL in Vietnam is also located in an area of very high risk in regards to UXO.

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1.5 DESIGN CRITERIA AND SPECIFICATIONS FOR TRANSMISSION LINES

The design criteria are described for both countries in chapter 7. While the criteria of the two countries are different, no particular discrepancies exist which could lead to technical problems when both sections will be connected. From an electrical point of view, each circuit of the TL in Lao PDR willallow a transmission of 2951 MVA, as opposed to a transmission of 2528 MVA in Vietnam. In addition to the design criteria, TL specifications, technical data sheets, plans & profiles and drawings for bidding purpose are attached annexes: Volumes 1 & 2 for Lao PDR, and volumes 4 & 5 for Vietnam.

1.6 COST ESTIMATE FOR TRANSMISSION LINES

The difference in cost per kilometer between both countries is mainly due to the tonnage of towers which is almost double in Vietnam compared to that used in Lao PDR for a same length. Nevertheless a new design, included in this report, uses one tension tower for 2 circuits, instead of 2 towers. This solution reduces considerably (roughly 3000 tons) the total weight of towers in Vietnam and the cost estimate of the TL. The price is still lower in Lao PDR where the conductors are bigger than in Vietnam. The difference may also come from the use of several contracts instead of an EPC. The lengths were adjusted for the final cost estimate, and the cost associated with the use of anti-theft bolts was included. Due to recent events in Lao PDR which affected the TL of similar project, the specifications of a temporary line were added, its price being included in the total cost estimate already. Considering the financial risks of an important failure, the consultant confirms that a temporary line is compulsory for such a project.

1.6.1 In Lao PDR

Description of the transmission line Length Cost / km Total cost estimate

Lattice towers 500kV TL with 4 x bundle conductors 795 MCM ACSR, OPGW 24 fibres, OHGW steel 74.5 mm2

59 km 735 000 US$ 43 365 000 US$

1.6.2 In Vietnam

Description of the transmission line Length Cost / km Total cost estimate

Lattice towers 500kV TL with 4 x bundle conductors 330 mm2 ACSR, OPGW 24 fibres, OHGW AACSR-PHLOX 116.2

93.5 km 921.070 US$ 86,120,000 US$

1.7 DESIGN CRITERIA FOR SUBSTATIONS

The design criteria for substations are similar between Vietnam and Lao PDR. In 500kV both countries recommended a 1.5 Circuit Breaker (CB) configuration, which is more expensive than a double bus bar configuration. The reliability of both configurations is similar, only the

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maintenance of the CB can be done without outage in case of a 1.5 CB configuration. Nevertheless this heavy maintenance is now scheduled every 10 years, then double bus bar can be chosen in Lao PDR, especially if we need to reduce the prices in order to reduce the wheeling charges. The 230kV is 1.5 CB configuration or double Bus Bar in Lao PDR, and the 220kV in Vietnam is generally double bus bar with one additional transfer bus.

1.7.1 In Lao PDR

According to the tripartite meeting held on 25 January 2011 in Hanoi, a final option for Hatxan configuration was adopted i.e. double bus bar for 500, 230 and 115 kV switchyard, and 3 AT 600MVA. In taking into account the schedule of installation and in order to save interest during construction, two transformers will be installed from the beginning and the third one will be installed when needed according to the schedule of commissioning of the IPPs. However the cost of the third TR is included in the global cost estimate, and then in the loan budget. A new step was considered without the final construction of the 500/230kV. This step consists in constructing a TL in bypassing the future site of the whole substation with a 230kV TL, with a taping to supply the 230/115kV switchyard. This section of 230kV TL will be dismantled once the 500/230kV substation is constructed. The 500/230kV COD will be scheduled according to the Commissioning Operation Date (COD) of the second hydro project following Xekaman1/Xanxay IPP. The 230/115kV substation was planned in a first step with 1 TR 230/115 kV, and 2 in final stage, however the capacity has to be finalized according the future PPA with other hydro projects. For memory, the wheeling charges calculation in section 12 are calculated without the 230/115 kV switchyard cost. In case the temporary solution is decided, the WC is calculated with the 500kV TL only, plus the bypass in Lao PDR, and the corresponding modifications, i.e., the temporary underground cables connection in Pleiku S/S.

1.7.2 In Vietnam

According to the tripartite meeting held on 25 January 2011 in Hanoi, both 500kV lines from Hatxan will be connected to Pleiku S/S. This option was confirmed later, as it was the option taken into consideration in the Masterplan 7. The temporary step with Xekaman1 / Xanxay to be evacuated in 230/220kV, has been considered and the impact cost was taken into account in the financial study. This temporary step consists in installing 2 feeders of underground cables 220kV from the future 500kV bays, to two additional 220kV bays, which will be used later for an interconnection with Cambodia. As we remain inside the Pleiku S/S area, the underground cables could be laid on the floor only, in concrete troughs for mechanical protection.

1.8 COST ESTIMATE FOR SUBSTATION

There is a difference of cost between both countries, in particular for unit cost of bay or diameter, the Vietnam side being more expensive. The reason may be due to a difference of specifications, in particular short circuit value of 3s instead of 1s and use of several contracts instead of EPC. In the present specifications EVN/NPT has accepted to remove the closing

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resistor on the 500kV circuit breakers, as the length of the line is not as long and there is no need for the CB to be equipped with closing resistors. The prices were then slightly reduced. On Lao PDR side, due to the very bad state of the new land, such as presence of two creeks, and level difference of 17m, it has needed an additional 10ha of land, which was approved by the Ministry of Industry and Mines.Only the solution, double bus bar with 3 x 600MVA AT, is estimated. For the 230/115kV S/S in Hatxan S/S, the configuration double Bus Bar with one TR in first step was considered. The final decision related to the number of TR shall be taken by EDL once their Masterplan is finalised.

1.8.1 In Lao PDR

The cost estimate was implemented for Hatxan S/S with several options

Hatxan Configuration Options, 230kV/500kV facilities only Cost Estimate

Option : 2 x BB configuration 3xAT 600MVA 55 534 500 US$

Hatxan Configuration Options, 230kV/115kV facilities only Cost Estimate

Option with 2 x BB configuration with 1 TR 230/115kV & 1 TR 115/22kV

6 229 000 US$

1.8.2 In Vietnam

Substations or Extension Works Cost Estimate

Extension of Pleiku S/S with Overhead Lines (1 diameter for 2 feeders in 1.5 CB configuration)

13 300 000 US$

Extension of Pleiku S/S with Underground Cables (1 diameter for 2 feeders in 1.5 CB configuration)

23 300 000 US$

Extension of Pleiku S/S with moving of different bays in order to avoid crossing of 500kV TL

24 100 000 US$

1.9 SYSTEM STUDY

1.9.1 Review of PDP in Lao PDR

The demand forecast of the PDP takes into account a large mining development. In 2015 the consumption of Attapeu region is expected to jump to 9,500 GWh with a peak demand of 1400 MW, with these figures respectively 360 GWh and 60 MW in 2010. Only 20% of the electricity from the hydro projects in the southern region will be dedicated to Lao PDR, while the remaining 80% will be exported to Vietnam. As explained in the interim report, this could only be done between two Transmission System Operator (TSO) or control centres, which do not exist in Lao PDR. Taking into account the hydro projects, the demand forecast and the industrial projects, Lao PDR would need to generate 13,000 GWh in order to cover the demand (residential and industrial) and the exports to Vietnam. This figure is higher than the hydro projects in southern region, this energy may flow from northern projects in order to cover southern demand and

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export requirements, but in that case the planned 230kV backbone is too weak to enable the sufficient energy transfer. The latest version of the Lao PDP, dated July 8th, presents several main changes compared to the previous versions:

The 500kV backbone has been removed and only the 230kV backbone has been kept and a new 500 kV substation is implemented: Ban Sok, which is connected to Ban Lak and then Thailand and not connected to Hatxan.

The hydro power plant Xepian Xenamnoy is connected to Ban Sok and Nam Kong 1 hydro power plant is connected to Saphaodong at 115 kV level and Xekaman Xanxay is also connected to Saphaodong at 115 kV level, instead of Hatxan through the double circuits line 230 kV from Xekaman 1. The hydro power plants Xekaman 4A and 4B are not more connected to Hatxan or to another substation. These changes may reduce the export to Vietnam and change the wheeling charges calculations.

There is not more 115 kV level at Hatxan substation, the 20% of the sharing out of the hydro generation for the Lao PDR could not be delivered from Hatxan.

Nevertheless the assumptions used for the network studies have been kept with the whole planned hydro power plants connected to Hatxan and 20% of the generation delivered to the Lao system, because the issues are worse for load flows, voltage drops and stability in case of high energy transfer. Therefore a lower energy transfer will reduce the constraints.

1.9.2 Review of PDP in Vietnam

The Vietnamese Master plan, which covers the period until 2025 (Master plan Number 7), is approved by the Prime Minister on July 21st. For this period the demand is expected to grow strongly with a yearly growth rate of 11% between 2015 and 2020 and 8% between 2020 and 2025. The existing installed capacity does not cover the demand and in 2010 the load shedding was used periodically. For that reason Vietnam has launched large projects for the implementation of generating units in Vietnam. The Hatxan Pleiku interconnection, with the implementation of the associated hydropower plants in Lao PDR, takes place within this context.

1.9.3 Review of Greater Mekong Masterplan

This Master plan was prepared in 2007 by Tokyo Electric Power Company (TEPCO). It is oriented towards interconnection development and its assumptions are still valid except for the Lao PDR demand forecast. This Master plan supported the necessity of the 500kV Ban Sok Pleiku interconnection for financial and technical reasons, and stated that if the interconnection were to be made at 230 kV, instability risks may occur.

1.9.4 Network Studies

The network studies were carried out in Vietnam by the Institute of Energy (IoE) for the Master plan 7. The assumptions adopted by the interconnection studies are the same as those of the Master plan 7 to ensure coherence between the studies. The location of the interconnection in Vietnam is Pleiku, validated by the MOIT and confirmed by the Master Plan 7. Therefore only this location has been studied with one variation, the temporary connection at 220 kV to Pleiku.

1.9.5 Connection to Vietnam Network

Direct connection to Pleiku

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The interconnected system has been modelled and studied for two load levels: peak and off peak and for the years 2015, 2020 and 2025. For all studied cases, for normal condition and in case of single contingency the system remains stable. At peak load, even in 2015 four 500 kV lines around Pleiku are over loaded, in normal conditions or in case of single contingency. These lines are: Pleiku-Dak Nong, Dak Nong-Cau Bong, Pleiku-Di Linh and Di Linh-Tan Dinh. These lines are very long and equipped with serial capacitor, for stability purpose, these capacitors are now limited to 1000 A and should be up-graded to 2000 A. It should be noted that these reinforcement, should be done before 2015, even in case of the interconnection line Hatxan Pleiku is not implemented. In addition, before 2025, the short circuit current in Pleiku will over shoot the technical limit of 40 kV. This is a big issue, which cannot be solved by implementing new transmission elements. This problem should be solved with changes in planning methods and operating rules. Pleiku is a key substation in central area of Vietnam and the network in this area should be re-designed in order to solve this problem.

1.9.6 Temporary Connection

The planning for the implementation of the transmission equipment is tight because Xekaman 1 and Xekaman Xanxay are expected to be in operation for the end of 2015. A transitory solution has therefore been studied.

This solution has been checked for 2015 with only Xekaman 1 and Xanxay connected because stability problems may occur if the other hydro power plants are to be connected to this temporary connection. For the studied cases no stability problems have been detected in normal condition and in case of single contingency. The same 500 kV lines around Pleiku are overloaded, therefore it is supposed that the reinforcement of these lines is planned in the Master plan 7 and will be done before 2015.

1.9.7 Network Study Conclusion

The demand forecast in Lao PDR should be assessed and the level of export confirmed. The splitting of the hydro generation (20%-80%) between Lao PDR and Vietnam should be technically organized, such as through a contract between EDL and EVN. The 500kV lines around Pleiku should be reinforced, which is likely to be consistent with the framework of the Master plan 7. The two interconnected systems should adjust their operating rules, reserve margin, and load shedding scheme, in order to take advantage of the interconnection.

Hatxan 230kV Hatxan 500kV Pleiku

500kV

Xekaman 1

Pleiku

220kV

Hatxan

230kV

500kV Lines

Used 220kV

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SECTIONS 1.10 TO 1.12 NOT DISCLOSED AS PER ADB’S PUBLIC COMMUNICATIONS POLICY (PARA 97)

1.13 IMPLEMENTATION SCHEDULE

A global schedule, including a timeline for the construction of Xekaman 1 and Xanxay IP’s, is set forth in Annex 2.8 and 5.9. Notably, the deadline to begin construction of the transmission facilities is July 2013; According to ADB, the financial close could not occur before April 2013, and then to comply with July 2013, the bidding process shall be launched before the financial close.

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2 BACKGROUND

As per the Terms of Reference (TOR) for the study provided by the ADB, the context of the study is as follows: 1) Lao PDR has significant hydropower potential, estimated at about 18,000 megawatts

(MW), but only 663 MW has been harnessed so far. Thirty-three potential hydropower sites have been evaluated for development and 11 projects with a total capacity of 4,000 MW are expected to be developed in the next 15 years. Realizing the country's hydroelectric power potential is challenging due to domestic resource constraints on financing its development, as well as very significant safeguard considerations. Recognizing the need to attract financing, the Government is strongly promoting private sector involvement; and as such, most of the future projects will be developed by independent power producers under concession agreements with the Government. Due to a fairly low domestic power demand and a rapidly growing power demand in other parts of Southeast Asia, most of the country's hydropower is destined for export, which provides an opportunity to generate much-needed foreign currency revenues to the Government. These revenues will enable investments in rural electrification as well as in other social development and poverty reduction programs. Lao PDR's export of hydropower also benefits other Southeast Asian countries like Thailand and Vietnam by providing economically efficient and climate-friendly power sources as compared to more expensive thermal power generation.

2) Vietnam's economic growth over the past decade was in average about 7.5% per annum. This growth was achieved through sustained business-led growth in economic output and employment. Vietnam faces a growing electricity supply deficit as a result of strong economic growth. The Sixth Power Development Plan (2006-2020) projects electricity demand to grow at:

16% per annum (base-case scenario) during 2006-2010, 11% per annum during 2011-2015, and 9% per annum for the remainder of the period.

Such high growth rates reflect the country's high level of economic activity. In order to meet its demand, Vietnam is exploring the possibility of importing electricity from its neighbouring countries, especially Cambodia, Lao PDR, and Peoples Republic of China (PRC) where investments in hydropower projects make imports competitive compared to local coal and gas fired power generation. The governments of Lao PDR and Vietnam signed a framework agreement in March 2008 to trade power that provides power sale arrangements of up to 5,000 MW by 2020.

3) Regional electricity trade through interconnectivity of electric power grids will provide significant economic benefits for individual countries. Such trade will enable Vietnam to (i) reduce national investments in the power reserves maintained to meet peak demand; (ii) provide a more reliable supply of electricity, including power supply from an interconnected network in case of power failure; (iii) reduce operational costs; (iv) reduce greenhouse gas emissions and other pollutants; and (v) increase consumers' access to the cheapest and most environment-friendly sustainable source of electricity. In Lao PDR, it will provide foreign revenues from taxes on the sale of electricity and from wheeling charges that will help the country to implement its rural electrification and poverty reduction programs.

4) The Feasibility Study was carried out in close coordination with Electricité du Laos (EdL), Electricité du Vietnam (EVN) and independent power producers (IPPs) that will be

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involved in the hydropower development in southern Laos. The Hatxan Substation in Lao PDR will be the connection point between the Laos-Vietnam interconnection that has to meet the Vietnamese technical standards, and the future Laos-Thailand interconnection that will have to meet the Thai technical standards. Therefore, the compatibility of having the Vietnam and Thailand power grid systems synchronously interconnected through the Lao PDR territory was checked. Although the Thai Power Utility, EGAT is not at all involved in this TA, the Thai standards will be observed by EdL in respect to the planned Na Bong 500/230kV power transmission line and the hydropower projects developers that are supplying or will supply Thailand.

5) The proposed Project is also required to comply with the development policies and plans of EdL and EVN, as well as with the project designs of IPPs with respect to the capacity of the power system, its configuration, system stability and fault levels, insulation coordination, load dispatching and communication facilities, operation and maintenance procedures, and safety aspects.

6) At the end of April 2011, the construction of Xekaman 1 Project is more than 20% progressed corresponding to 100 MUS$, with the implementation of the diversion tunnel and dam foundations completed. The PPA with EDL, the PPA with EVN/NPT as well as the Concession Agreement were signed end of November 2010. The tariff is already fixed (see Chapter 12.1). PPA and CA are signed for 25 years, after which the project is transferred to Lao PDR.

7) The potential for the connection of projects Xekong 4 & 5 (total capacity of 630MW), which are developed by Russian Companies, to Hatxan S/S, has definitely been abandoned as these investors are now in discussion with developers of the SLACO bauxite mine.

8) After the submission of the Interim Report on 18 December 2010, the Draft Final Report on 6/06/2011, the last tripartite meeting was organised in Vientiane beginning of September 2011 addressing the following major issues:

a. PDP in Lao PDR

b. PDP in Vietnam

c. Location of Hatxan Substation

d. Environmental & Social Due Diligences

e. IEE/EIA in Lao PDR

f. Temporary situation in 230kV, problem in Pleiku Substation

g. Limit of properties in Hatxan Substation

h. Bidding process in Vietnam

i. Split 80/20% To date a), d), e), f), g), h) & i) issues are not resolved.

9) A variety of different missions have been undertaken, in particular to validate the new location of Hatxan S/S, the Delivery Point, the validation of the TL routes (in particular on Lao PDR side as the access is difficult), and missions associated with the commencement of IEE and IOL activities for both the TL and S/S in Vietnam and Lao PDR.

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3 SCOPE OF THE DETAILED FEASIBILITY STUDY

3.1 PROGRESS STATUS OF THE FEASIBILITY STUDY

The scope of works of the TA consists of carrying out a detailed feasibility study on the planned 500kV transmission line between Hatxan (formerly Ban Sok) Substation in Lao PDR and Pleiku Substation in Vietnam. The proposed project consists of (i) 152.5km of double-circuit 500kV transmission line; (ii) the new Hatxan 500/230/115kV substation; and (iii) the extension of the Pleiku 500/220kV substation (subject to the pending possible changes mentioned above). The feasibility study was implemented in two stages with a break between the two. The break occurred after the submission of the Interim Report. The ADB then decided to continue the TA after the tripartite meeting in Hanoi on 25 January 2011, in spite of several remaining issues described in the current Draft Final Report. In the current report a summary of the E&S Due Diligences for the hydro projects is presented in Chapters 4 and 5, while separate draft reports were previously provided on 11 March 2011 for Environment and 21 March 2011 for Social/Resettlement. To date the Consultant has not received any comments. The current Final Report includes the IEE and an IOL/LARAP for both countries, both Due Diligence in the annexes. Regarding financial matters, the final wheeling charge value based on different assumptions is calculated in the current report, and the viability of the projects checked, even though both PPA could not be consulted in detail by the ADB Consultant. This means that the preliminary risk analysis in chapter 12 is based on assumptions, based on experience feedback of recent similar projects in Lao PDR. Similarly, the viability assessment of the hydro projects which will be developed by Viet-Lao Power Joint Stock Company (VLPC), is checked in the current report. The information gathered from Xekhaman 1 PPAs, was used for all the other IPP projects, as hypothesis. EIA in Lao PDR: The budget allocated in the ADB TA (which was intended to be used for an Initial Environmental Examination (IEE)) is not sufficient to cover such an activity, as required by Lao PDR's new regulation. Pending a solution, an incomplete IEE has been provided to the4 ADB. The draft IEE can be used as a scoping document to help the ADB and Lao PDR negotiate a way forward. LARAP in Vietnam: A solution was proposed and employed for the preparation of a Draft LARAP using data from a survey of land losses and impacted trees and houses carried out along the axis of the TL, based on a draft IEE (including an IOL) conducted by PECC4 in February 2011 (see Chapter 6.3.2).

3.2 INTERIM REPORT (PHASE 1)

The Interim Report which was submitted on 18 December 2010 mainly provided the initial results of site missions and an initial assessment of the viability of the project, in particular the 4EDL and WREA have not permitted the consultant to conduct the mandatory consultation session in order to finish the IEE, since they consider the project requires a full EIA, which has significantly different consultation needs. Therefore the IEE remains incomplete.

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first consideration of the possibility to transfer the 500kV transmission facilities on the Lao side to a Transmission Project Owner (TPO) under BOT arrangements. The Interim Report also included:

- The design criteria of TL and S/S for both countries, with technical difficulties on site

- The initial results of Impact studies of associated hydro projects compliance assessment, according to ADB and Lao PDR regulations,

- The initial assessment of the different PDPs, showing the difficulties both countries are facing due to the huge growth rate in energy needs.

3.3 DUE DILIGENCES

In March 2011 two separate Due Diligence Reports for Environmental and Social/Resettlement aspects of the associated Hydro Projects were sent for action to the concerned parties.

3.4 WORKS ON SITE

In April and May 2011, site missions were conducted for the finalization of a transmission line route in Lao PDR, just after the validation of the new location of Hatxan S/S. In addition the Delivery Point location was validated by all parties, taking into account the new border between the two countries involved. Additional survey activities at Hatxan S/S. E&S activities for an IEE and IOL/LARAP were carried out in June 2011.

3.5 DRAFT FINAL REPORT

The Draft Final Report was submitted at the beginning of June 2011 and the third tripartite meeting was organised on 6thSeptember 2011 in Vientiane. Remaining activities to get data with IPs and utilities took place until the end of 2011.

LAO PDR / VIETNAM Asian Development Bank CONSULTANCY SERVICES FOR PREPARING THE BAN-SOK PLEIKU POWER TRANSMISSION PROJECT 500 kV OHL_TA 6481-REG


3.6 REVISED TASKS SCHEDULE OF THE TECHNICAL ASSISTANCE

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BAN SOK – PLEIKU DRAFT FINAL REPORT 10-02-2012 Page 26 of 208

4 ACTIVITY IN THE FIELD

4.1 ENVIRONMENTAL SPECIALIST FIELD ACTIVITIES

4.1.1 Laos

Since 2009 four field surveys have been undertaken; two of which were conducted to examine the three transmission line corridor options and potential locations of the substation, including corridor walking surveys, and two to survey the five hydro power projects at various stages of development. The latter surveys were for the due diligence audits, and involved comparing the requirements as defined in the documentation with site implementation, and reviewing on site conditions in relation to what was recorded in the available documentation. Since the start of the project in 2009, a total of about one month has been spent in Sekong and Attapeu Provinces undertaking various surveys.

4.1.2 Vietnam

For the Vietnam IEE, one field survey was completed in mid-2010, involving the driving survey of two alternative alignments and the inspection of the site for the proposed substation expansion. A second survey was carried out in June 2011.

4.2 SOCIAL SPECIALIST FIELD ACTIVITIES

4.2.1 Lao PDR

Since 2009, the Consultant has made four joint trips with EDL staff and the local consultant to the project site, including all optional alignments of the TL, for the purpose of identifying the social and physical impact of construction and operation and the requirements for resettlement, compensation and specific assistance to severely affected or vulnerable groups (see the attached map of the area showing the identified impacted areas, villages and resources). Visits included scoping of the TL and substation site, due diligence of associated facilities, preparation for IOL and SES, consultation with local government and affected households and completion of the IOL and SES. To date, the Consultant has spent approximately two months in Sekong and Attapeu Provinces undertaking various surveys.

4.2.2 Vietnam

The Consultant has made two visits, in June and September 2010, to Kon Tum and Gia Lai Provinces to visit the ROW of the Transmission Line and the Pleiku substation and to guide the preparation of social impact assessment and Inventory of Losses (IOL). These visits were taken in cooperation with the PECC4 social and environmental specialists, The Vietnamese authorities have placed severe restrictions on the movement of foreigners in the border areas with Lao PDR, as well as on contact between foreigners and local populations/local Government staff. As a result, PECC4 resettlement staff and social specialists have conducted the consultations with affected communities, as well as undertaking the IOL and SocioeconomicSurvey (SES)The Consultant made a third visit to the PECC4 offices at Nha

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Trang in May 2011 to review IOL and SES survey process and results to ensure compliance with ADB social safeguard guidelines and to undertake a joint analysis of the data from two site surveys (the first in 2007 and an updated survey in February 2011).

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5 ENVIRONMENTAL AND SOCIAL DUE DILIGENCE OF THE ASSOCIATED PROJECTS

5.1 GENERAL

According to the ADB’s policy on loans for transmission lines, all power generation projects which will feed electricity to the Hatxan substation (S/S), and then across the Hatxan to Pleiku transmission line (TL) are considered associated projects, i.e., any components that make the S/S and TL operational. All associated projects must meet basic ADB safeguard requirements and additionally, must meet all Lao PDR or Vietnam requirements (depending on the location of the associated project), before linkages to the S/S-TL system are possible. As part of the Feasibility Study ToR, the Consultant was instructed to complete safeguard due diligence audits on all associated projects, which had any safeguard documentation available. Of the six (6) projects listed by the ADB, five were found to have at least some basic documentation. Only Dak Emeule could not be examined as no safeguard documentation had been completed. Xekhaman 2 (a seventh project, not included in the TOR) that will eventually feed power to the S/S-TL complex, also had no available documentation, and therefore was not reviewed. Separate draft Due Diligence reports, providing a detailed assessment of each project’s compliance with environmental and social safeguards have been prepared and were submitted to the ADB on 11th March 2011 for Environment, and 21st March 2011 for Social/Resettlement. The following material is the list of gaps and key non-compliances in both Environment and Social safeguard documents of all associated projects. Further information is provided in the draft Due Diligence Reports. The due diligence assessment varies in its level of detail from project to project, since the available documentation was inconsistent – both in terms of level of data supplied for each project and internal consistency of data for individual projects.

5.2 SUMMARY OF GAPS IDENTIFIED IN THE ENVIRONMENTAL DOCUMENTS OF THE

FIVE ASSOCIATED PROJECTS;

5.2.1 Xekhaman 1

As of March 10th 2010, the project had an approved Feasibility Study and Social and Environmental Assessment documentation, including the certificate to proceed from WREA (dated March 2010). The approval, however, was conditional and WREA still has to provide a new certificate indicating that conditions had been met. The construction period began in 2008 and, in March 2011, construction of the project was around 20% completed. Key issues with environmental and social safeguard documentation include: 1. The EIA must be reorganized and consolidated (as the document is current written it is

difficult to identify the nature and magnitude of potential impacts and there are many internal inconsistencies);

2. The EIA must be revised to address the correct TL corridor (from the project to the Ban Sok S/S) and this analysis needs to be more detailed, since under Lao PDR requirements, this TL should have its own EIA.

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3. Revise the EMP to include all the mitigative measures defined in the EIA and then prepare a timetable, monitoring program and costs associated with actual actions;

4. Complete at least two rounds of compliant consultation sessions;

5. Present an EIA implementation timetable;

6. Require the concessionaire to commit to preparing regular safeguard monitoring reports according to a timetable and as defined in the EIA.

Aside from Item No. 1, these revisions could be provided in an EIA addendum, requiring 3- 4 person-months for one experienced technical specialist, 4 months for one national counterpart and at least two field trips and two consultations, plus additional time for translation into Lao.

5.2.2 Xanxay

Construction of Xanxay has not yet started, and separate environmental and social safeguard documentation is not available for the Xanxay Project. However, this project has the same approval status via the Xekhaman 1 certification, as it was been included in the Xekhaman 1 EIA / EMP. While the Xekhaman 1/Xanxay EIA and EMP provide a great quantity of information, very little is relevant to the Xanxay Hydropower Project, which under Lao PDR and international standards is classified as a large dam (32 MW and a 1.6 km2 reservoir) requiring its own EIA; or, at the very least, a complete section in the Xekhaman EIA. This does not exist. Therefore the Xanxay project needs: • A standalone EIA and EMP. • An examination of impacts (as noted in the Xekhaman EIA) not addressed in the

Xekhaman EIA document, including cumulative impact assessment and impacts associated with spoil disposal and only marginal clearing of upstream basin, etc.

To complete the Xanxay EIA and its EMP 2.5 to 3 months of international and 4 months of national consultant time, plus expenses and at least one 2 – 3 weeks field investigation will be needed.

5.2.3 Xekhaman 4

The Consultant completed an IEE, which itself is marginally compliant with ADB SPS 2009. No approvals have been provided for this project and only very preliminary reconnaissance surveys of the area have been completed. The IEE concludes that a full EIA will be needed for this project. 1. In such an ecologically diverse/sensitive area (international specialist surveying the area in

the past suggest that the Xekhaman headwater area may even be Asian elephant and Asian tiger territory) the EIA will be complex—particularly as there is a Xekhaman 4 and 4A downstream facility planned. There will also be a need for a number of special technical surveys including a wildlife survey and a biodiversity assessment.

2. An examination of the NTFP use by local communities would also be needed. To meet ADB environmental safeguard requirements, such an EIA would require at least 8 person-months of international specialist input as well as 8 person-months for national counterparts.

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5.2.4 Sekong 3A

The EIA & preliminary geological exploration & some site land surveys have been prepared. Safeguard documentation was submitted in May 2010 to WREA but no comments have been received to date. This EIA does not comply with ADB guidelines, Vietnam’s EIA guidelines as defined in Decree No. 80 and Circular 08/2006, Vietnam’s equivalent to Lao PDR’s Decree 112/PM, as well as with Lao PDR Decree 112/PM. To bring this EIA into compliance requires a complete reorganization and rewrite, plus:

1. An EMP.

2. A credible consultation program needs to be completed and inputs assembled, then integrated into the EIA and its EMP.

3. Previous fisheries surveys have indicated that 20% of the Sekong River’s fish population is endemic, constituting a potential national biodiversity treasure. A sub-basin wide biodiversity survey needs to be completed.

4. A comprehensive discussion of the proposed water diversion from the Sekong to the A Lin and A Luoi hydroelectric power facilities in central Vietnam, needs to be included in the EIA (it is currently only mentioned in the project description).

5. The effects of this dam in relation to the others on the Sekong River and its contribution to downstream effects and any potential mitigative actions need examination. ADB TA 6367, (Project No. 40083) would serve as a useful starting point.

6. Potential impacts of waste discharge and insect borne diseases (malaria, yellow fever, schistosmiasis, and cholera) around the reservoir need assessment

The work required to bring this EIA into compliance with ADB standards will be 3-4 person-months of international and 4 months of national consultant input, plus a complete consultation program, with results integrated into the documentation. The cost of the biodiversity survey will be additional and cannot be established until a short scoping exercise is completed.

5.2.5 Sekong 3B

This EIA is almost a duplicate of Sekong 3A. This EIA does not comply with ADB guidelines, Vietnam’s EIA guidelines as defined in Decree No. 80 and Circular 08/2006, as well as Lao PDR Decree 112/PM. The EIA concludes with 16 points, none addressing EIA. The last 4 suggest that the contractor, working with the Project Management Unit (which is not discussed in the EIA), prepare the EMP and monitoring program; a fundamentally non-compliant sequence of tasks. The EIA:

• Needs to be reorganized and checked for consistency, plus major gaps defined in the DD report need to be filled

• Needs to address tropical insect-borne and human waste pollution-related diseases, facilitated by the newly impounded water.

• Previous fisheries surveys have indicated that 20% of the Sekong River’s fish population is endemic, constituting an essential biodiversity treasure. A sub-basin wide biodiversity survey needs to be completed; i.e. cumulative effects.

• A comprehensive discussion of the proposed water diversion, from the Sekong to the A Lin and A Luoi hydroelectric power facilities in central Vietnam, needs to be included in the EIA.

• A complete EMP needs to be prepared as part of the EIA.

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• Finally, a comprehensive consultation program needs to be designed, delivered and properly recorded in the EIA.

As with Sekong 3A, the work requires to bring EIA into compliance with ADB standards will be 3-4 person-months and 4 months of national consultant plus a complete consultation program, with results integrated into the documentation.

5.3 SUMMARY OF GAPS IN THE CONSULTANT DOCUMENTATION AND PROPOSALS

FOR SIA AND LARAPS FOR ASSOCIATED PROJECTS

5.3.1 All Projects Compliance with ADB and GOL Social Safeguards

In general, the social management and resettlement plans associated with hydropower projects planned for Attapeu and Xekong Provinces, if conducted in accordance with the existing plans and documentation, are not compliant with ADB, or with the Government of Lao’s social safeguard guidelines. For example, in-migration (of workforce and followers) associated with the hydropower projects will have a significant impact on the populations and services of these two Provinces, and is not currently addressed in any social impact or social development planning documentation. While documentation for all projects is generally non-compliant, there is a significant difference in the approach and documentation of Xekhaman 1, which broadly follows GOL and ADB guidelines but is non-compliant in specific detail (refer to the section below), and all other hydropower projects for which documentation has been provided. These projects do not ab initio attempt to follow GOL or ADB procedures and guidelines. There are five major factors which appear to be inadequately provided for in all SIAs and RAPs of the associated projects, and which are non-compliant with Lao Government and ADB Guidelines on Involuntary Resettlement in the present Consultant documents5. These include:

• Consideration of workforce in-migration – the impact of the in-migration of the planned Vietnamese workforce and an accompanying incoming population (estimated to be at least 20,000 to 40,000 in each Province) will be massive, both on the populations of these Provinces and on their administrative, health and educational services. This poses a potentially significant risk to health and social stability, and is likely to have an irreversible effect on the situation and status of the indigenous people living in this area;

• In a related aspect, the planned total exclusion of the Lao labour force from employment on these hydropower projects (which is not consistent with the Lao Labour Code – which states that 90% of the unskilled workforce and 80% of the skilled work force should be Lao) precludes major benefits to the local and national economy and human resource development;

• Consideration of the impact on indigenous people (ethnic minority groups) and women – the relocation of impacted indigenous (ethnic minority) villages, and proposals for their consolidation into larger villages (comprised of different ethnic minority groups), as planned will radically impact on their social structures and livelihoods. Women’s issues (and differential gender issues, in general) are also not considered;

• Feasible livelihood restoration plans – the proposed restoration of livelihoods by specific measures, for example, by irrigated rice production and provision of forest “plots” within which to gather non-timber forest products, for villages relocated from the reservoir, and pumped irrigated gardens and pond aquaculture, for downstream villages facing loss of

5 And in the Environmental Compliance Certificate conditions currently required by the Lao authorities in the case of Xekhaman 1, the only project for which a completed SIA and RAP are available.

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river flow and fisheries are untested (i.e. have not been demonstrated to be feasible) and may be impracticable;

• Public involvement and consultation – the level and character of consultations, participation and information afforded to the affected populations, as at present conducted or proposed, does not follow ADB or Lao Government Guidelines, and is inadequate for any effective role on their part in decision making or management of resettlement, relocation or livelihoods restoration; and

• Consideration of HIV / AIDS and other health risks (e.g. water-borne and vector-borne disease) – the absence of any specific or adequate HIV/AIDS awareness and prevention programme poses a significant risk to the local and the incoming population alike.

Furthermore, there is no resettlement planning for any of the four associated projects6 in the sense in which ADB and the Lao Government Regulations require it (i.e. a time-bound planning system in which all aspects of the impact of the project are recorded, information provided to and consultation conducted with the affected population, planning undertaken in the light of a census of all the affected people and a socio-economic survey conducted of the wider impacted population, compensation rates and other entitlements stated an income restoration programme identified, and a grievance mechanism established). This is a systemic difference between the approach adopted and the planning undertaken by the Vietnamese consultants and that of the ADB and the Lao Government.7 To bring associated projects into compliance, a framework approach and technical assistance program at the provincial and / or district level is recommended. The framework and TA program would also address the need for integrated province-wide planning of mitigation measures. The TA should provide sufficient international and domestic consultancy and the costs of WREA, EDL and MEM capacity development and participation. The TA should be provided over a period long enough to provide support during the design and implementation of all the associated hydropower projects and TLs. In addition to the justification for this approach on social management / mitigation grounds, some of the measures needed, for example for in-migration (the consideration of the significant workforce moving to the area) and health (specifically HIV/AIDS awareness and prevention programmes) can only be feasibly implemented at the provincial level through existing and strengthened Provincial Government structures. Another factor to be addressed is the almost total lack of knowledge of GOL and ADB policy and practice on the part of the Vietnamese developers and consultants (as reported by the Vietnamese developers and consultants). Early action, such as an ADB supported workshop, is therefore recommended to address this gap and to agree on planned action to address it. A framework approach to resettlement planning and policy, following Lao and ADB Guidelines, would embrace related measures for social aspects of the hydro-power sector, and of the associated work force in-migration. The strategy would immediately be needed also in Sekong Province. The LARAP prepared for the Ban Sok-Pleiku TL includes a Resettlement Policy Framework designed to achieve these purposes. 6 At least – there is no planning for which documents have been made available to consultant. 7 Vietnamese consultants indicated that they were not aware of the Lao PDR Government Regulations (EIA 2002 or 2010 and Decree on Compensation and Resettlement 2005 and Technical Guidelines 2005 or 2010) and did not have a copy of these regulations.

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5.3.2 Xekhaman 1

It is important to note that (as indicated in section 5.2.1) construction of the Xekhaman 1 Hydro-power Station is well advanced. In terms of social management, this includes the provision of a relocation site (one single site for all five (5) villages). The Social and Resettlement Specialists (international and national) visited the planned relocation site downstream of the dam, on the bank of the Xekhaman. This land was provided by the Xanxay District Council. The site and the planned land area appear adequate, but there are a number of aspects which should be the subject of more detailed and prolonged study and planning, notably:

• Agreement on the site location and planning was the subject of consultation involving a visit of representatives of each family together with village and District officials. It appears that the process did not include the possibility of permitting independent and separate identification of relocation sites by the five inundated village communities and seven other villages losing agricultural land;

• The location of all five communities in a single large village area (though separate by some hundreds of meters from one another) is likely to be socially disruptive to existing local relationships and structures. It appears that the preferences and opinions of the residents of the five (5) villages have not been collected and taken into consideration during the relocation planning process;

• It is currently planned that each household will be provided with 2 ha of forest. Given the traditional practices of the people to be relocated, which is essentially based on shared access to a surrounding forest, limited only by feasible distance and respect for neighbouring community access, the 2 ha per household is thought to be grossly inadequate and conceptually mistaken;

• In a related issue, the expectation that resettlers will practice swidden agriculture and hunt in the currently designated “Protected Forest” immediately across the river from the resettlement site, has not been the subject of any consultation with other groups using the forest for this purpose;

• The resettlement site is adjacent to a 9,000 ha rubber plantation, which has been planted during the past eighteen months, leading almost certainly to the employment of members of these households as labor on the plantation;

• No provision has been made for an adequate HIV/AIDS awareness programme among the Vietnamese work force at the hydropower accommodation site or among the surrounding population.

The audit has shown that the SIA and RP preparations for the project are, in important respects, non-compliant with both ADB and Laotian Guidelines, including in specific aspects of the February 2010 GOL Decree (Appendix 2) but also in respect of previous GOL Decrees, Guidelines and Regulations. The draft RP is based on the stage 1 outline studies and only preliminary consultation, in which it was regarded as risky to provide as yet undetermined project design and social impacts or resettlement proposals to the population, since they would have limited understanding of the issues involved and would suffer “consultancy fatigue” (i.e. detailed consultation on the draft RP and participatory planning of resettlement activities has yet to take place for this Project – despite the fact that construction has commenced). Though accepted by WREA for the purpose of the issue of the conditional certificate, the SIA and RAP do not meet ADB or GOL Guidelines, notably in respect of consultation with and disclosure to APs, the level of detailed and time-bound resettlement planning and livelihoods restoration, and the absence of any adequate HIV/AIDS awareness and prevention programme.

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The Schedule 02 of Concession Agreement for the Xekhaman 1 Hydropower Project “Integrated Environmental and Social Obligations of the Company” spells out the elements in the Vietnamese consultant’s ESIA, EMP and RAP which are certified to be obligatory and conditional in the approval of project implementation. Conditions of the WREA certificate include carrying out the measures outlined in the draft RAP, including the proposed three-stage consultation and information process, however, do not include changes to meet the non-compliances identified above. A more detailed point by point breakdown of compliance in respect of specific elements of the RAP has been provided in the draft Due Diligence Audit Report for Xekhaman 1. A review of activities on site indicated further non-compliances with ADB and Lao PDR legislation, including requirements of the Schedule 02 of the Concession Agreement:

• Very few local people have been engaged by the construction contractor as part of the existing work force at the Xekhaman 1 dam site, other than housing and camp site construction labour: The Vietnamese management have organized the recruitment of the work force from urban centers in Vietnam, and do not anticipate any local recruitment, except possibly for housing construction and service trades. The Lao who are working in the ancillary facilities at the dam site tend to be recruited from provinces and urban centres in Central Lao, rather than from local people.

• There is no external (WREA, EDL, MEM or any other) monitoring of construction activities at the Xekhaman 1 site, and as indicated above, the required monthly reports are not being provided to WREA.

Furthermore, no due diligence review was undertaken of the transmission line connecting Xekhaman 1 to Hatxan substation, as no documentation was available for review. The lack of social assessment and resettlement and compensation planning of the TL is another gap in Xekhaman 1 safeguard documentation. These deficiencies have been partially addressd in a resettlement policy framework provided with the Ban Sok Pleiku TL LARAP as dicussed in the previous section. The RPF provides outline terms of reference for the preparation of retrofit short LARAPs which should be the subject of technical assistance to ensure that Lao and ADB guidelines are followed in all continued resettlement implementation, including adequate consultation with the five villages to be relocated due to the Xekhman 1 reservoir impoundment. The work to bring the LARAP and SIA into compliance with ADB standards will be 4 international man-months and, 7 national man-months with results integrated into the documentation.

5.3.3 Xanxay

As described previously, the Xanxay Project was considered as part of the Xekhaman 1 Project, and no separate documentation was available on this project. The Xekhaman 1 safeguard documents do not include any information on social impact, resettlement and compensation required by the Xanxay Project. The work required to bring the LARAP and SIA into compliance with ADB standards, will be 2 international man-months and, 4 national man-months with results integrated into the documentation.

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5.3.4 Xekhaman 4

The IEE for Xekhaman 4, which provides substantial documentation on the proposed resettlement and relocation proposals, including the budget, does not follow or comply with either the Lao WREA 2010 Decree or the WREA Regulations and Guidelines. The issues with this documentation are consistent with the issues outlined above and for the Xekhaman 1 Project. The work required to bring the LARAP and SIA into compliance with ADB standards, will be 3 international man-months and, 5 national man-months with results integrated into the documentation.

5.3.5 Sekong 3A and 3 B

Sekong A and Sekong B documents concerning social impact and resettlement are identical in wording and format (including sections describing the social and cultural characteristics of the impacted population). Neither the procedures and format nor the provisions made for impact mitigation and resettlement follow the Lao WREA 2010 Decree and previous WREA, Regulations and Guidelines or the ADB Guidelines. The documents state that there will be 4,000 workers brought from Vietnam in each project, and that the total number of the incoming population of families and support workers is likely to be several times that number, however, no further assessment of the impact of this incoming population or development of mitigation measures is provided. Other issues with Sekong 3A and 3B documentation are consistent with the issues outlined above and for the Xekhaman 1 Project. The work required to bring the LARAP and SIA into compliance with ADB standards, will be 4 international man-months and, 7 national man-months for Sekong 3A, and 4 international man-months and, 7 national man-months for Sekong 3B, with results integrated into the documentation.

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6 THE PROPOSED ROUTE OF TRANSMISSION LINES

The transmission lines to be supplied, constructed, and installed under this study shall be 500kV double circuits with four bundle conductors per phase. They will be strung on self-supporting lattice steel towers, extending eastward from Hatxan substation in Lao PDR to the proximity of Pleiku substation in Vietnam. This covers approximately a distance of 152.5km i.e. 59km in Lao PDR and 93.5km in Vietnam.

6.1 TRANSMISSION LINE IN LAO PDR

6.1.1 Map with different proposed routes

Fig 1

The map above shows the situation at the time of the Interim Report, with the original location of Hatxan S/S at km27 of road 18A. According to an official letter from MEM dated 24 March 2011, Ref: 0377/MEM/EPD, due to the future construction of an airport at km27, Hatxan S/S had to be moved to km37-38 as shown in Fig 2.

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Fig 2

6.1.2 Technical Constraints

In the Interim Report the preferred route was option 3, as per Fig 1. However, due to the relocation of Hatxan S/S, this option is no longer appropriate and consequently option 2 is now preferred. Option 1 (TEPCO option) was abandoned due to potential greater impacts on the Dong Ampham NPA.

The relocation of Hatxan S/S towards the Eastern Part reduces the length of the Lao PDR transmission line by 6km.

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6.1.3 Environmental Impacts

6.1.3.1 Pre-Construction Period

During this period most of the impacts can be avoided through careful planning and environmentally friendly design considerations. The five impacts8identified were discussed in detail in the IEE and its Environmental Management Plan (EMP). All the environmental impacts are set forth in the IEE which was provided end of June 2011.

A. Concession Agreement Documents do not contain Environmental Safeguard Specifications as defined in EMP of IEE

Limited Administrative Support for Implementing EMP Tasks Environmental assessments, environmental clauses, compliance monitoring and enforcement depend to a large extent on how strongly senior agency officials support enforcement of environmental safeguards. These agencies include primarily the Ministry of Energy and Mines, Ministry of Foreign Affairs, WREA and the Attapeu Governor’s Office. The prospects of rapid economic gains, fuelled by lucrative development deals from neighbouring countries, may make environmental protection, which may slow down the pace of the economic returns, difficult to support. To build environmental awareness, EDL’s Environment Department proposes to conduct, as part of the 3-day training workshop described in the IEE, a ½ day awareness raising seminar to show the economic benefit-cost relationship of good versus bad environmental stewardship. Excellent examples exist in Lao PDR and agencies such as the Mekong River Commission (MRC) may be invited to participate.

IEE and EMP not Distributed or Translated into Lao Language

Field audits conducted by the consultant in many countries and projects revealed that EIA documents are not systematically distributed and very often, are not translated from English to the local language. This is true in Lao PDR. Without EIAs, and EMPs in hand, local officials and contractors cannot implement needed mitigation measures and a project proceeds without any environmental safeguards, despite having an approved environmental assessment document. To avoid this problem, EDL will ensure that the approved IEE and its EMP will be translated into Lao and that these documents, including the original English versions, will be provided in both hard (13-14 sets) and soft copies (4 CDs) to all relevant agencies. Delivery of these documents will be followed up by a member of EDL-Attapeu visiting the recipients to ensure that material was received and that any additional comments are assembled.

B. Vegetation and Soil Erosion Allowed to Proceed For this project, tightly controlling the work area boundaries will be key to ensuring unnecessary removal and clearing are kept to a minimum. To address this, EDL will specify in the contract specifications that an area no larger than 80m x 80m can be cleared and used for tower construction. Tracks created for bringing in the tower components will also remain tracks, just wide enough to accommodate the machinery used to erect the towers and to maintain them.

8Strictly speaking Preconstruction ‘impacts’ are actually a set of actions-not undertaken,and as a result triggering serious impacts during the construction and operating periods. They are essential to address during the preconstruction period.

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Contract specifications will also include a set of steps the contractor must follow to rehabilitate each tower construction site. These are defined in the IEE and its EMP.

C. Loss of Old Growth Forest Patches and Biodiversity Given the large scale clearing going on in Attapeu, removal of additional old growth forest for the TL needs to be carefully examined to establish if there are important biodiversity forest patches in the path of the TL. Therefore, the survey team locating the TL towers will be required to include a qualified biodiversity specialist who will identify any large or old growth forest patches in the way of the TL. These data will then be evaluated by EDL, WREA and the Forest Department, to identify if a biodiversity survey is warranted and if TL diversions are needed.

D. Construction Compliance Monitoring and Inspection Not Applied While the EMP and the environmental covenants can be very clear and specific, if there is no one knowledgeable enough to undertake compliance monitoring, inspection and regular reporting, little of the EMP will be implemented or completed. This is based on very solid past project experience. Neither EDL-Attapeu, PWREO or contractors have the skills in environmental compliance inspection/monitoring and reporting or the necessary resources to implement such monitoring. During the field visit, the consultant observed that for the other major projects such as the Xekhaman 1, no copies of the EIA documentation for this 490MW power station were available, despite the fact that the project was >20% into the construction period. To avoid this situation EDL will ensure that the IEE and its EMP are translated into Lao language and made available in both hard and soft copies to the Attapeu PWREO and EDL offices and to the contractors. EDL-Vientiane will require that all those receiving the documents acknowledge their receipt and understanding of the material. Given that the province has no monitoring equipment, a complete set will be purchased as part of the ADB loan, for use by the Attapeu WREA. A full list is provided in the IEE, and they will be purchased prior to awarding the contract for the works. With the assistance of WREA, EDL will organize a 3-day workshop for Attapeu-PWREO, EDL, any interested district representatives and the contractors, focusing on the implementation and follow up of environmental assessment documents and their EMPs. Details are provided in the IEE.

E. Bird-TL Interactions Historically, bird and power line interactions are of two types a) electrocution when the bird shorts out a conductor and b) when birds, particularly large, migrating birds, collide with conductors at night since bird navigation, highly dependent on magnetic fields, is disrupted by high voltage transmission lines’ magnetic radiation. Bird electrocution is rare for high voltage lines since the corona effect is strong and will frighten off almost all birds attempting to land on a conductor or insulator. Birds’ landing on the towers is without negative side effects. Bird-TL mortality is very difficult to quantify since any dead birds fall to the ground and are often eaten by predators within hours of being killed or wounded. Past estimates in Europe and North America put bird electrocution in the 10s of thousands per year, but mostly for TLs where voltage is less than 115kV. Without 24h/day monitoring it is impossible to establish accurate mortality figures. The project area, particularly the NPA is home to a number of large migrating birds such as the Giant Ibis, Black Ibis, Sarus Crane and several large vultures. Their travel routes

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would take them across the TL, leading to possible bird-TL collisions, especially at night (although none of these species are known to fly at night). The TL and in fact all TLs in Sekong, Attapeu and Champasak cut across the East Asian-Australasian flyway used by long range migrants, certainly boreal migrants which nest in Siberia such as the Sarus Crane, and overwinter in the Mekong basin and wetlands, including some of the area of Dong Amphan. These species could be at risk of collision with conductors. A four-week long bird movement and migration survey focusing on large birds such as ibis, cranes and vultures (most sensitive to bird-TL mortality) plus other rare and endangered migrating species, will be conducted to determine which species migrate across the TL, and to determine when and where they do so9. Based on these data, a mitigation action plan (if necessary) will be implemented, consisting of possibly installing beacons to warn birds of approaching wires, etc. (a procedure successfully used in France for many years). The survey work will include two components, a literature review to establish the state of knowledge and the latest preventative measures applied and secondly, Indigenous knowledge surveys of local communities to identify flyway locations, key species and migration patterns. No action will be taken until the first analysis reveals whether there is an issue.

6.1.3.2 Construction Period

Identified construction period impacts focus on soil erosion, water quality, air quality, noise and health effects.

A. Soil Erosion and Stream Degradation Most of the soil along the TL alignment is thin topsoil over a laterite clayey subsoil, which when vegetation removal occurs, is easily eroded. When dried without compaction this can create very dusty conditions. Erosion will be possible at the access tracks to the towers and at the foundation construction sites, which will require backhoes and a crane. Unless carefully monitored, contractors could decide to skip proper surface draining repair and management during construction, leading to potentially chronic but small-scale erosion along the access tracks to the towers and at the tower foundation construction sites (about 22). To prevent such erosion the contractors will be required to follow a six step process defined in the IEE. The TL passes through an area with many streams and small rivers. Aggregate for the concrete foundations for the TL towers must come from approved sources and none can be mined from nearby streams or floodplains. The contractor caught mining streams will be fined the equivalent of having the same amount of material trucked into the tower site and will have to rehabilitate the degraded area.

B. Water Quality and Public Health Degradation (B1) Sewage and Garbage

Failure by contractors to adhere to good housekeeping practices as defined in the contract and a lack of enforcement by the Attapeu WREA inspectors will lead to longer term contamination at construction camp sites all along the ROW, leaving behind a generally unattractive corridor of impact, with dissatisfied, sceptical and disappointed local people. The WREA inspectors will be expected to ‘undertake

9Given the 1000s of km of TL being proposed for Saravan, Sekong, Attapeu and Champasak provinces by 2015, this study should have broad value for EDL and Lao PDR

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regular environmental compliance monitoring, using the EMP as their guide10. A monitoring checklist will be prepared by the contractor as part of each monitoring cycle and a monitoring report will be submitted to EDL’s Project Management Unit (PMU) quarterly, for the duration of the construction period. Sewage and garbage must be properly disposed of and any such materials found in water courses will lead to an immediate fine of no less than 1.6 Mkip (200 US$) and double that amount for each additional day that such materials remain in the water course near the work areas. Packaging waste will be recycled or disposed of in the local landfill.

(B2) Oil and Heavy Metal Contamination Contractors have a habit of driving their vehicles into any open stream and proceeding to wash them with complete disregard to the pollutants entering the water such as waste oil and grease, hydraulic and brake fluid and heavy metal dust from brake linings, etc. EDL will inform Attapeu WREA that washing vehicles in streams is to be strictly forbidden, will specify this in the contract specifications and monitors will be required to report such violations to the EDL project engineer when it occurs. In addition, waste oil products must be accounted for and disposed of through a legitimate recycling firm. The contractor will be required to prove that a waste oil contract or letter of agreement was signed and the waste oils were picked up and recycled. Proof required will be copies of official receipts submitted to the PMU monthly. Volumes of these wastes on site will usually not exceed 500L and not more than 1000L at the contractor’s staging yard. Five additional measures were defined in the IEE.

C. Insect Born Diseases Outbreaks Construction sites in the tropical regions, where malaria and dengue fever occur, can become sources of disease outbreaks due to pools of stagnant water created after a rain or flood event at land depressions at the construction sites or inside used construction equipment or materials such as old tires. One discarded tire collecting rainwater is enough to cause a serious malaria outbreak within 7 days. To prevent this the contractors will be required to inspect every site as part of the completion checklist to make sure that no areas where water can pool is left behind and that all construction waste materials such as tires are removed from the site.

D. Terrestrial Habitat Loss The clearing of an 80m x 80m area around each tower is of little consequence in the first 15km of the TL corridor, but as the TL alignment crosses the Xe Xou River and along the old Ho Chi Minh Trail, large trees and patches of tropical lowland jungle will be removed and any large trees within and bordering the 70m-wide corridor will also have to be removed. The location for the TL would be on the SW side of the road, opposite the NPA border, on a bench, already cleared of most large trees. The TL route option 2 (the recommended alignment), just before and after it crosses the Xe Xou River. To try and minimize this impact, the team surveying the towers will be required to mark any large primary growth forest patches on the survey maps and indicate any that will be within the 70m-wide corridor. These patches will then be investigated via a biodiversity inventory (recommended as a special technical study) following this IEE. EDL will consult with Ministry of Agriculture and Forestry (MAF) and WREA officials to determine their significance and to determine if the TL needs to be realigned to protect these patches (if these prove to be significant).

10 For sewage pit privies at worksites are suggested; biodegradable trash can be buried, and all plastics and non-biodegradable materials disposed of at an approved landfill site.

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E. Degradation of Dong Amphan National Protected Area The TL TEPCO option would pass directly through the southern part of the NPA, paralleling NH 18A, creating an approximately 150m wide (Map 2) open/disturbed corridor. This would present effective barrier for some species like the gibbon and other mammals. Coupled with a two-year construction period in the heart of the NPA the TEPCO option was eliminated from further consideration. The work associated with options 1 and 2 will impact the NPA for the last 9.2km of the TL. For the remaining distance it will not encroach into the NPA, but will be close enough that a protocol for construction workers needs to be defined. While the first 300-400m of land inside the NPA boundary has been badly degraded by illegal occupation and farming, noise and construction activity will result in low level impacts. However, construction workers entering the NPA to harvest wildlife, edible wild plants, fish and aquatic insects for food and for sale could become a real problem, particularly in the more remote areas near the Xe Xou River and its tributaries. At the start of construction, workers will be informed that when near the Dong Amphan NPA, which will be around km47 of option 1 and 2 starting at Ban Somboune of the TL, or when working on the last 9.2km of the TL, entrance into the NPA away from the construction areas will be strictly forbidden and a zero tolerance policy will be put in place. Details are provided in the IEE. Consultation with the MAF will be required to discuss potential impacts on the NPA and proposed management measures to ensure that there is agreement. Given the potentially significant impacts on the NPA, additional management measures may be proposed such as providing signage indicating the NPA boundaries in the vicinity of the TL or conducting biodiversity education in local villages.

F. Noise Pollution Noise disturbance will be a minor during construction as most of the work will be carried out in uninhabited or very sparsely populated areas, with any known habitation more than 500m away from the edge of the RoW. To minimize noise disturbance, work will only take place between 08:00 and 17:00.

G. Air Pollution Construction period air pollution will consist of dust and emissions from operating machinery. This, however, will be a very minor impact. Despite the work taking place in areas devoid of settlements, controls on vehicle idling and equipment maintenance will be imposed through construction inspection and regular reporting by PWREO monitors. Equipment and vehicles will be shut off if not in use for more than 3 minutes and all will be maintained according to manufacturers’ specifications. Dust will be carefully and continuously managed. Dust control will be particularly stringent along any unpaved roads used to access the transmission tower sites and passing within 50m of a settlement. Any such road through a settlement area will be watered according to a written schedule agreed to between the contractor and the PMU. Nuisance dust will also be minimized through disturbing only the minimum area necessary and conducting progressive rehabilitation. Ground vegetation, such as grasses and shrubs, will also be left undisturbed under the line within the ROW below the required clearance height.

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6.1.3.3 Operating Period

Operating the TL involves little human activity but the high voltage passing through the conductors has a number of effects that need to be defined and mitigated.

A. Noise and Electrical Charge from Conductors and Insulators (Corona Effect) When under and near high voltage power lines (400-500kV) one often hears a hissing or popping sound and there is a smell of ozone (as after a strong rain when there has been lightning). This can be quite loud and there is the potential for nuisance impacts on both people and animals by this phenomenon. It is not directly harmful to health, but long term exposure must be avoided. It can also be felt as a static electricity effect; a tingling on the skin or static electricity in the clothes. Given that this TL runs through wet, warm tropical climatic conditions and that at their lowest point, conductors will be just (11m in Lao PDR & 8m in Vietnam) from the ground, the corona effect will be pronounced and disconcerting for most. The corona effect can emit a steady noise measured as high as 50dBA, exceeding permissible levels for rural residential areas at night time. For that reason a 100m human use exclusion boundary will be recommended for either side of the outside conductor and will be posted by EDL-Attapeu and the District officials through warning signs and information along the alignment. Warning signs will be placed on the towers and midway between each tower along the corridor warning of the electrical discharge, crackling and hissing and danger-stay away signs (See Chapter 6.1.3.1.B). To further address this impact, a portable noise meter will be purchased and used by EDL-Attapeu to monitor noise levels at varying distances from the TL tower centerline. A survey design is suggested in Task 3.2 of the EMPs mitigation table.

B. Health Effects Related to Electric Field and Magnetic Field Emissions Since the 1970s the debate continues over the potential health dangers related to electric and magnetic fields created by high voltage transmission lines. The two measurements that are usually referred to are the electric field effect, measured as kV/m and the magnetic flied effect, measured as micro Teslas or (µT). Most recent publications refer to these two as the electromagnetic field effect (EMF). In the face of overwhelming evidence (Calif. Dept. of Health Science, 2002; EU SCENIHR Report, 2009; A. Huss et al. 2008; 2007NIEHS (US), 1999 and O’Carrol and Henshaw) suggesting otherwise, power companies continue to use the 100µT as the limit for human and animal exposure. This limit dates back to pre 1998 and is considered inadequate in the literature and by the consultant. The studies referenced and others provide adequate proof that levels of 1.0 µT can double or triple the risk of diseases such as childhood leukaemia, adult brain cancer and Alzheimer. EDF data on EMF under 400kVA power lines suggest that at 30m distance from the axis (the centerline of the Tower) µT levels average 12 µT and at 100m it is 2 µT; measurements taken at 1m above the ground. For this TL the outer conductors will be 19m apart, except for 3-4 ‘transposition’ towers where the outer conductors will be 38m apart. Ehtaiba et al (2008) completed a comprehensive study to establish EMF levels at varying distances from the TL axis for a new 400kV per line in Libya. They produced a number of informative diagrams that indicated that for a double circuit 400kVA line measured at 1m above ground and with a line current at 1,000 amps, the µT levels at 30m from the TL axis (and about 23m from the outside conductor of the TL) would likely be between 3-6.5 µT, more or less in line with EDF’s data.

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Increasing the measurement height to 1.5m and the voltage to 500kVA, and the distance between outside conductors to 20m, the µT levels are estimated to be 24 µT at 30m and 4 µT at 100m from TL axis. In 2009 the Electric Power Research Institute (EPRI) in California reviewed the seven major reports on EMF. Six of the seven indicated that exposure of > 0.4 µT from high voltage power lines was dangerous to health, particularly children. Using the data compiled by Henshaw (2008), including the fact that Italy, Sweden, Switzerland and Tasmania, Australia have increased the distance of high voltage lines from settlements and are enforcing a no-agriculture zone, as well as the EPRI review, the following limits will be set for this 500kV TL:

Minimum recommended distance from the outer conductor to any human use of the corridor will be 50m or a total of 75-80m on either side of the Tower axis;

Livestock operation, including cattle and poultry will be recommended outside the 75m distance from the outside conductor

No crop-based agricultural activity will be recommended within the 30m boundary from the outer conductors; and

These limits and restrictions will be posted on signs on each tower and one between two towers along the alignment and in District offices conductors where the line is crossing a road or river.

EDL will conduct regular (every two months) surveys, measuring µT levels at 30m, 50m, 75m and 100m at 1m and 2m above ground at sites within 400m of settlements and inside the closest residences to the outer conductor and any area used for agriculture. Readings will be used to adjust the boundaries as required. Two sets of meters such as the Tecpel EMF Tester (Gauss Meter)-Product ID: EMF -701 A: [http://www.allproducts.com/ee/tecpel/Product-20041123145642.html] will be purchased for this survey. The measurement results will be posted at District offices and the survey results will be communicated directly to local residents so that they are aware and can make an informed decision.

C. Spill Of Hazardous And Toxic Material There are no hazardous materials used for maintenance of the towers and conductors. The S/S however does have batteries and cooling oil which must be filled into the large step-up and step-down transformers used to vary the voltage being sent to various customers. This oil is highly refined mineral oil or vegetable oil, with a fire retardant added. The retardants used to be PCBs and are now mostly fluorocarbons, which do not contain dioxins or PCBs. The used oil is toxic, containing heavy metals and other materials from the transformer windings and must be treated as a toxic substance. Large transformers must be serviced every six months to two years. EDL operators will be required to follow strict international practices as defined in the operating guidelines for transformer maintenance, provided as part of this project. EDL will ensure that these guidelines are fully understood by S/S operators. As a precaution, EDL will require that all transformer coolant oil received at the Ban Hatxan S/S be certified in writing as dioxin and PCB free and includes chemical composition data, as with any hazardous material. Volumes shipped and stored will be relatively small. Used oil will be assumed to be toxic and disposed/reprocessed according to international best practice, and shipping record logs kept up to date.

http://www.allproducts.com/ee/tecpel/Product-20041123145642.html

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D. Continuous Habitat Disruption in the TL Corridor The towers, conductors, access tracks and the area underneath the TL, i.e. the 70m wide operating corridor, will be disturbed on a regular basis, likely every 6 months and every time vegetation needs to be trimmed (reaches >3m high).Therefore, the area will remain chronically disturbed. Since the ground cover will not be disturbed, unless a tower foundation must be replaced, this impact will be small. In fact this action will likely attract bird, mammal and herptiles species that thrive in ecotones. When working close to the NPA, repair crews will be made fully aware of the proximity of the NPA and the no-entry rules will be specified.

6.1.4 Social Impacts

6.1.4.1 Pre-Construction Period

During this period most of the impacts can be avoided through careful planning and consultation with affected persons. The primary impact during this phase is the same as the first impact listed in the ‘Environmental Impacts’ section’ – i.e. limited (or no) administrative support and lack of consultation / disclosure of safeguard documents and plans.

6.1.4.2 Construction Period

Major impacts of the construction period include: land acquisition and associated livelihood impacts and visual amenity impact. Additional impacts include impacts on traditional culture, values and livelihoods of the indigenous peoples living in the project area. Approximately 400 households are likely to be affected – 23 directly affected with the remainder affected by impact on communal forests. There is also the potential social and cultural impact of the construction, maintenance and presence of the TL in these areas, and related developments. Potential social and cultural impacts are exacerbated in the TL area by the presence of ethnic minority populations. Due in part to the low density of settlements along the TL route, and in part to efforts to avoid settled areas in TL planning, there are no affected structures or people that need to be relocated. To minimize land acquisition and eliminate the need for resettlement, project designers have identified land for the substation and have located the TL along land borders. Land acquisition impacts of project construction include permanent acquisition of land for tower footprints totalling 135 units and compensation for the trees/crops higher than 3 meters along the ROW, which will need to be cut. There will also be some impact from temporary acquisition of land for construction access to towers. Land affected primarily includes swidden land, permanent tree crops (primarily teak) and communal forest land (this is the same impact for all route alternatives). Some scattered rice paddies are also likely to be affected. Loss of this land may have significant impact on the livelihoods and food security of the five villages of indigenous peoples, mainly Brau, who live along the newly improved road which runs along the Ho Chi Minh Trail on the old 18B route. These are significant impacts and require compensation and assistance to the communities concerned, which are budgeted in the LARAP. A Detailed Measurement Survey (DMS) will be required to confirm the impacts and compensation once the detailed design is complete.

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6.1.4.3 Operating Period

In addition to the permanent land acquisition discussed in the previous section, during operations, there will also be some impact on community forests due to use restrictions in some areas under and adjacent to the power lines. Benefits of the project will derive from increased employment opportunity related to the annual clearing of the TL corridor, and from specific planned measures to restore or enhance any loss of livelihoods, such as improved access to health facilities, training and educational programs, electricity connections to the recently installed supply system at Somboun, water supply, and small scale irrigation, agricultural and livestock development.

6.1.5 Preferred route in Lao PDR

According to the change of Hatxan S/S, the global route length is reduced, compared to the interim report. A site mission was undertaken to validate each angle point, and as a result, a certain number of them were adjusted, and a new angle point PI 9B was created. The coordinates are presented below:

Point of

Intersection

East North

PI 1 730 703 1 633 536 PI 2 730 677 1 633 363 PI 3 735 154 1 627 619 PI 4 738 134 1 627 386 PI 5 743 755 1 630 567 PI 6 746 907 1 628 486 PI 7 749 313 1 624 483 PI 8 752 286 1 621 610 PI 9 758 321 1 618 573

PI 9B 759 067 1 618 957 PI 10 760 375 1 620 499 PI 11 764 064 1 621 497 PI 12 766 029 1 620 557 PI 13 768 604 1 620 691 PI 14 770 821 1 621 939 PI 15 771 873 1 626 019 PI 16 773 846 1 627 345 PI 17 775 123 1 628 986 DP 775 242 1 629 012

It shall be noted that the Delivery Point is not a tower, but the middle of a span, of which 50% is in Vietnam, and 50% in Lao PDR (see 6.3.5). The route of the TL on Lao PDR side is presented Fig 3 and Annex 1.



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6.2 HATXAN SUBSTATION (LAO PDR)

6.2.1 Environmental considerations

The Ban Hatxan substation structure will require a >15ha footprint, but up to 100ha have been reserved at the new site, located at km37 along NH18A. This large area is needed as a safety buffer due to the high voltage lines coming in and out of the S/S facility. The Hatxan substation location is validated, although the exact position of the switchyard has to be confirmed, due to the hilly area and the presence of two creeks. On the Vietnamese side, there have been no further changes to what was discussed in the Interim Report; the double circuit will be connected to Pleiku S/S. The new Hatxan S/S location is not adapted for a substation construction unlike the previous location at km27. In fact, due to the presence of two creeks, and level difference of 17 meters, the levelling, compacting and sustaining works will involve huge excavation works. Due to the presence of both creeks it was not possible to locate the 16ha necessary for the whole substation within the 100ha allocated by the local Authorities. Aside from the ground cover to be removed (totally flat terrain) for construction of the building area, the fencing off of a safety zone and the handling of coolant, no other environmental issues are anticipated; nevertheless environmental assessment will be required11. An existing 3-year operating period corona effect noise and EMF survey along the TL will be extended to the S/S, to establish operator safety requirements as well as safe distances for the public. Given that there are two small streams draining the area around the SS platform, all runoff water from the SS will be diverted to a small catch basin where it will percolate into the ground and where any spills can be contained before the runoff water reaches either of the streams. Site Topography The terrain is mostly hilly with the southern local road being the highest elevation at 170.00 m. leading down to an elevation of 158.00 m. in the north-east and 162.00 m. in the north-west. The gradients of the hills are about 4 degrees in the north-east and 5 degrees in the north-west. The substation finished grade shall be proposed at elevation 165.00 m. through the entire area for 115 kV, 230 kV and 500 kV switchyards. The site works will consist of 144,320 m

3for earth-

filled and 146,760 m3for earth-cut. Maximum height of backfill soils will be about 7.00 m., and

will be located North-East of the 500kV switchyard. Segmental Retaining Wall (SRW) should be suitable owing to economizing in design and aesthetic appearance. The storm water from outside shall be trapped with the main concrete gutters that run along the southern boundary. They will drain to the east and the west sides of the area and flow out from the outlet into natural channels. Furthermore, there are substation drainage systems designed to remove inside rainwater and waste water through road gutters, sumps and drainage pipes. They will also drain into natural channels in the north-east and the north-west. 11 LaoPDR’s new environmental assessment guidelines require separate EIAs for large S/Ss of this type.

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6.2.2 Social Considerations

Investigation of the Hatxan Substation site has shown there to be no housing or permanent agricultural land use. The site is on stony and sloping land which has been used for surface quarrying for road materials in recent years. Rotational use of the land for swidden agriculture has yet to be determined, but any identified impact could be mitigated by compensation.


The new Hatxan S/S location area was not adapted for a substation construction, such as the previous location at km 27. In fact, due to the presence of two creeks, and level difference of 17 meters, the levelling, compacting and sustaining works increase the final estimate by 1.5 M US$. Due to the presence of both creeks it was not possible to locate the 16ha necessary for the whole substation within the 100 ha allocated by the local Authorities. In consequences, the Consultant has requested to the Ministry of Mines additional 10ha in order to place the switchyard in the best conditions. The approval from the Ministry was given in May, and the switchyard will be located as follows:

Fig 4: Previous dedicated Land

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Fig 5 : Map from Land Department for Final limitation of Land

6.3 TRANSMISSION LINE IN VIETNAM

6.3.1 Environmental Impacts

All the environmental impacts are set forth in the IEE in annexes 3.1 & 6.1.

6.3.2 Social Impacts

IOL and SES work undertaken by PECC4, based on a 32m. ROW indicates that a total of 786 households are likely to be affected along the Vietnam ROW, of which 237 are affected permanently (mainly through losses of tree crops), and 501 temporarily. Forty-eight (48) households will lose houses, and will have to be relocated. In all cases, relocation will occur within the existing residential areas of the concerned communities. The biggest impact on agricultural assets is on rubber plantations (78 ha) with 41,606 trees needing to be cut down for tower foundations and 2.2 ha of plantation in the TL corridor. Other permanent loss is to production forest, with the loss of 42 ha in the ROW.

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The route of both options is similar from a technical point of view. The access, even quite far away from existing roads or tracks, is easy. In addition the relief and steep slope are generally avoided. Finally ADB’s Consultant has chosen the Western route, instead of the Eastern one, because the Western one will go through more smooth terrain, which will make construction work easier. The only problem with both routes is the arrival at Pleiku substation. As the Pleiku S/S is completely saturated, only one location is possible for the substation extension, and this involves crossing 3 existing 500kV transmission lines, Ialy – Pleiku 1 & 2, and Pleiku-Phulam. Since the Inception Report, the Consultant reminded that he cannot recommend such configuration which is completely banned in most countries, and which will jeopardize the stability of the Vietnamese network. The possibility and overcost related to the installation of underground cables along the last 500m before Pleiku S/S are set forth in Section 9.2.11 and 10.2.2. Another technical point that drew the ADB Consultant’s attention is the total width of the RoW imposed by the Vietnamese Government, namely 32m. The RoW width is 70m in Lao PDR and 80m in Thailand. The calculation below (Fig 6) shows clearly that 32m clearance is not sufficient in forest areas and a corridor free of vegetation should be at least 52m (20.7m x 2 + 5m x 2 for safety clearance). If this minimum corridor, in which the vegetation shall be completely cut, is not in place the reliability of the line is not ensured and tripping will occur very often during a windy period.

LAO PDR / VIETNAM




Fig 6 Calculation provided by Vietnamese side As for Lao PDR side, the surroundings of the Delivery Point are not easy with several steep slopes, heavy forest and difficult access. In addition the DP is located at 1020m altitude. However the 32 m RoW can be kept for housing construction purposes, which means no construction is permitted within the 32 m corridor. Agriculture of small plantation is allowed, except sugar cane. The coordinates of the angle points (PI) of the TL in Vietnam are as follows:

The route of the TL on Vietnam side is shown on the map Fig 7 and annex 4.1.

LAO PDR / VIETNAM




6.3.4 Preferred Route in Vietnam

Fig 7

LAO PDR / VIETNAM




6.3.5 Delivery Point

The Delivery Point was finalized on site on 8 April 2011. Two major issues previously encountered have been resolved: 1) There is a No Man’s Land on both sides to be complied with:

110m on the Vietnamese side, according to a letter from High Command of Border Guard of Kon Tum province, dated 7 December 2010, and

100m on the Lao side, according to an official letter from MEM dated 24 March 2011, Ref: 0377/MEM/EPD

2) In addition as shown by the brown line on Fig 8 below, the border close to the road 18A

has changed and does not correspond to the current reference documentation, i.e. Google Earth map.

Fig 8

The profile below in Fig 9 shows the Delivery Point above 1000m altitude.

LAO PDR / VIETNAM




Fig 9

LAO PDR / VIETNAM




The investigation on site allowed validation of the last Dead End Tower on the Vietnam side, allowing a Delivery point to be marked on site. However, this DP will not be retained as the official DP, because when projecting it on a straight line to find the corresponding last Dead End Tower on Lao PDR side a ravine was intersected. As a result, a flat location for the Dead End Tower was found, which is marked on site, and the Theoretical Delivery Point was calculated. Its final references in WGS 84 are:

- DELIVERY POINT : 775 242 E – 1 629 012 N - DEAD END TOWER LAO PDR: 775 123 E – 1 628 986 N - DEAD END TOWER VIETNAM: 775 359 E – 1 629 038 N

The type of conductors, the responsible entity who will supply and string the conductors, the OPGW and earthwire, will be determined later. However, a problem does arise in that the EVN/NPT is not supposed to sign any contract with the TPO. In addition, there will be some additional technical commitments, between the Transmission Entities, such as telecommunication, differential protection equipment compatibility, etc, which should be stated in an agreement (PPA or other, see chapter 13). The decisions related to these pending issues shall be taken in order to finalise the bidding documents, and could be validated during the tripartite meeting in Vientiane.

6.4 PLEIKU SUBSTATION (VIETNAM)

6.4.1 Connection in 500kV

The existing Pleiku S/S is one of the biggest substations in South East Asia, and the Social and Environmental impacts of the extension of 2 additional bays will not affect the area more than the present situation. Just as mentioned already, on a technical point of view, the connection by overhead lines is not recommended and the underground solution needs to be investigated. Other possible connections to Kontum or Duc Co Substations were envisaged at the time of the Interim Report, however the direct connection to Pleiku was officially confirmed by the Ministry of Industry and Trade (MOIT) and this solution is included in the Masterplan 7 of Vietnam. As a result, the Final Report, including bidding documents, will consider this latter solution only.

6.4.2 Connection in 220kV

We will see in Chapters 9, 11 & 12 that a temporary solution is to evacuate the energy from Xekaman 1 – Xanxay in 230kV was considered. This solution would allow (1) to postpone the construction of the 500kV part of Hatxan S/S and (2) to limit the cost of the Wheeling Charges (WC), and investments. Both, the financial viability and the system stability were studied. From a financial point of view this is viable, even for a long period of time. There is no particular problem from technical point of view, as regards the difference of voltage between Lao PDR and Vietnam, respectively 230 and 220kV (see Chapter 11). The drawbacks of this solution, is an overcost, especially at Pleiku S/S, for which justification is provided in Chapter 13.

LAO PDR / VIETNAM




7 DESIGN CRITERIA & SPECIFICATIONS FOR TRANSMISSION LINE

7.1 GENERAL COMMENT

The specifications for 500kV TL in Lao PDR and Vietnam are respectively included in Annexes 2.1 & 5.1, the technical data sheets in 2.2 & 5.2, the drawings in 1.2 & 4.2, and the Plans and Profiles in 1.3 & 4.3. The spare parts and tools will be included in the price schedule. In addition the implementation of an Operation and Maintenance Manuals will be included in the scope of works or the Contractors. The TL voltage from the IPPs to Hatxan S/S will be 230kV. There is still an issue with the standards to be used by the Vietnamese developer. In particular the Vietnamese developer uses the ACSR 330 (ampacity of 730 A at 75°C), which is not well adapted for Xekaman 1 as the calculation shows that the installation of double bundle conductors, instead of one with 1272 MCM, is needed. The cost would then be saved. After discussion with Vietnamese Consultant, they will include spare parts in the bidding documents, specially dedicated to the project. Usually the NPT has its own spare part storage per region already, and do not include them in bidding documents. Regarding the conductors, the main difference between Vietnamese and Lao TL standards is the size of the conductors. They are both ACSR in type, but roughly 405 mm2 in Lao PDR, and 330 mm2 in Vietnam. However, their interconnection is possible. While it is not a problem for the interconnection (the difference in each country being possible), the country responsible for the supply and the stringing of the conductors between both dead-end towers, needs to be determined (see description Chapter 6.3.5). The 500 kV TL is equipped with 4 bundles conductors per phase, meaning that one circuit may transport more than 2500 MVA. Since the lnterim Report, a new type of tower has been proposed by the Vietnamese side, namely one sole tension tower for 2 circuits, which reduces considerably the weight and foundations works for each angle and dead-end towers (total number 31 angle towers). Both countries are specifying transposition towers for long distance. The Annexes 1.2 and 4.2 present the standard transposition tower used in Lao PDR and Vietnam, are presented. The only difference is that the transposition tower is a suspension one in Lao PDR, and a tension one in Vietnam. The spacing of 152.5km results in roughly one transposition tower every 21km, this mean 2 then 6 towers in total for 2 complete transpositions, two in Lao PDR, and four in Vietnam. The geometric characteristics are also different and set forth in the annexes. We will see in Chapter 13 that this difference of standards could create issues with regards to the maintenance of the Lao transmission facilities that may be carried out by NPT.

7.2 BIDDING CONFIGURATION IN BOTH COUNTRIES

The bidding packaging process of both countries is completely different. The description below applies also for Substation package. For Lao PDR, an EPC Contract bidding process is under implementation. To date, in Vietnam, EVN/NPT does not practice the EPC configuration, but instead several packages of different technical fields and split in several sections according to the quantity of

LAO PDR / VIETNAM




works are used. As an example, for TL, 93.5km could be split in 5 sections, roughly 20km each, and for each section these may be one package for foundations, towers erection, towers supply, conductors supply, insulators supply, conductors stringing, hardware supply, etc. In addition, in the bidding documents, the level of study is different to the one used for the EPC on the Lao PDR side. In fact a deep level of design, called by local Consultant “Feasibility Study”, is already done by the Consultant. For example, the towers are staked already, sized, calculated, soil investigation done and foundation sized, etc. This means that this “Feasibility Study” which under international standards, is in fact a detailed design, which is carried out by the Consultant (PECC) instead of the Contractor. Therefore, such FS would need one year of implementation, from the date of Masterplan 7 validation, due to the design’s approval process. This is the reason why some documents in annexes are missing for Vietnam side. As a result within this TA, it is very difficult for the Consultant to provide bidding documents under such packaging configuration, and what we could propose, is an EPC package, that NPT could use if they chose to. The EPC configuration has been strongly recommended to the Vietnamese side, in particular considering the accumulated delay and consequent tight schedule. This would allow exercising pressure on a contractor with delay Liquidated Damages on the delays. Even though this issue was raised during the last Tripartite Meeting on September 2011, the Vietnamese Ministry has not allowed the EPC packages for BanSok-Pleiku Project.

7.2.1 Level of Design for Bidding Purpose in LAO PDR

The package will consist of general and detailed specifications, including design criteria and guidelines, which will be prepared under this TA. The draft specifications, drawings, including plan and profiles for TL, technical data sheets and price schedules are in annexes 1.1 to 1.4 and 2.1 to 2.9, including UXO specifications. Normally the technical level of bidding documentation for EPC, should include the following works:

To study on a map with a scale of 1/50,000 the expected TL route construction areas; To select some TL route alternatives on the map; to visit the site; to work with local agencies in order to find out about land use planning information etc, review and modify the TL route to be suitable; to select at least two TL route alternatives, where one TL route alternative will be proposed and agreed with relative local agencies and provincial people’s committee.

To calculate the selection of conductors, ground wire, OPGW with number of fibre optic cores

To determine the polluted level of TL route area; to calculate preliminary insulator types

To determine the preliminary quantity of towers to be installed for TL route

To list the materials and equipment for TL route

To prepare the preliminary total cost estimate, and

To prepare, in detail, the main specifications of conductors, ground wire, OPGW , towers, foundations and insulators with the corresponding design criteria

This is the usual activity of an Owner Engineer before bidding, and after the contract is awarded, the Owner Engineer checks the detailed design implemented by the Contractor.

LAO PDR / VIETNAM




7.2.2 Level of Design for Bidding Purpose in Vietnam

The level of design in Vietnam is totally different to current international practices, notably for EPC contract purpose, as it is for Lao PDR side. For comparison we have highlighted in grey the tasks usually carried out by the Contractor. The design phases are divided into three steps:

1. Feasibility study The design works is described in summary as below:

To study on a map with a scale of 1/50,000 at expected TL route construction areas; To select some TL route alternatives on the map; to visit the site; to work with local agencies in order to find out about land use planning information etc, review and modify the TL route to be suitable; to select at least two TL route alternatives, where one TL route alternative will be proposed and agreed with relative local agencies and provincial people’s committee.

To demonstrate the need for investment into the TL project

To define the capacity of the power transmission line; voltage level; number of circuits.

To calculate the selection of conductors, ground wire, OPGW with number of fiber optic cores

To determine the polluted level of TL route area; and to calculate preliminary insulator types

To calculate the preliminary main earthing system

To calculate the steel tower family: suspension towers, tension towers due to wind & weight span and angle. To determine the preliminary weight of steel for each tower

To determine the preliminary quantity of towers to be installed for the TL route

To list the materials and equipment required for the TL route; and

To prepare the preliminary total cost estimate

2. Technical Design After the Feasibility Study stage is approved by the owner, the Technical Design stage will be implemented. The design works are described in summary below:

To list in detail the main specifications of conductors, ground wire, OPGW and insulators

To put the towers on a profile drawing for the whole TL route for the approved alternative;

To calculate and select the insulators in detail for each tower location;

To calculate the earthing system in detail for each tower location;

To calculate in detail the towers and foundations. To list the weight for each tower, and foundation types;

To determine the distance for transportation to the site (for each tower location);

To prepare in detail the list of materials, equipment, construction components for each tower location;

To prepare the overall schedule of electrical part, construction part, erection plan of TL route; and

To prepare the total cost estimate.

3. Detailed Design

LAO PDR / VIETNAM




After the Technical Design stage and the bidding result are approved by the owner, the Detailed Design stage will be implemented. The design works is described in summary as below:

To update and check the main specifications of conductors, ground wire, OPGW, insulators, etc. taking into account the bidding result;

To prepare the sag – tension for TL route taking into account the bidding result;

To prepare the list of materials, equipment, construction components for each tower location;

To prepare the steel tower manufacture drawings for erection work; and

To prepare the drawing of foundation types in detail. In EVN/NPT practice, the bidding documents are launched after stage 2. Even stage 3 is prepared by the Owner Engineer.

Comment 1: This practice does not give enough responsibilities to the Contractor, and can be used only with a Consultant belonging to a Utility, as is the case in Vietnam, because all the design responsibility is borne by the Consultant. This is certainly another cause of overcost of the installations, as the Contractor, if the design is oversized has no interest to optimize the design. Additionally, in the case of a mistake in the design, the Contractor also has no interest in informing the Owner, as he will redo the works. Comment 2:

The ADB’s Consultant points out that this configuration raises a considerable issue for the design activity in Vietnam; In fact, in starting from the validation of the Masterplan 7, a complete year is needed before the preparation of the bidding documents, as the design corresponds to the one the Contractor normally has to do, and the process of checking the design with the Owner takes a lot of time with several phases of review. In addition entrusting such part of the design to an independent Consultant means that the Consultant takes the responsibility of the whole construction design; responsibility that a Consultant cannot take under this TA.

7.3 TECHNICAL DESIGN CRITERIA

7.3.1 General Geometrical Design Criteria for Both Countries

ELECTRICAL CLEARANCE DATA

VERTICAL CLEARANCE AT MAX. OPERATING TEMP. SHALL BE AS FOLLOWS:

Lao PDR VIETNAM

ABOVE GROUND ACCESSIBLE TO PEDESTRIANS, UNCULTIVATED LAND 11.00 m 8.00 m

ABOVE STATE/MAJOR HIGHWAYS 14.50 m 12.00 m

ABOVE RAIL ROAD TRACK, NEAR SUBSTATION ENTRANCES 16.00 m 12.00 m at 70°C.

ABOVE CULTIVATED AREAS, GROUND ACCESSIBLE BY VEHICLES 13.00 m 12.00 m

ABOVE 500kV LINES 7.00 m 7.00 m

LAO PDR / VIETNAM




ELECTRICAL CLEARANCE DATA

ABOVE 230kV LINES 6.00 m 6.00 m

ABOVE 115kV AND TELECOMMUNICATION LINES 5.25 m 5.00 m

ABOVE DISTRIBUTION LINES 69kV AND LESS 4.65 m 5.00 m

ABOVE SHIELD WIRE OF OTHER LINES 4.00 m 5.00 m

ABOVE GAS PIPE LINES 13.00 m 12.00 m

ABOVE BUILDING NOT PERMITTED NOT PERMITTED

CROSSING NAVIGABLE RIVER (ABOVE MAX. WATER SURFACE) 16.00 m 16.00 m

HORIZONTAL CLEARANCE TO OTHER FEATURES SHALL BE AS FOLLOWS:

Lao PDR VIETNAM

STATE/MAJOR HIGHWAYS 75.00 m 1.3 x Height of tower

RAIL ROADS 65.00 m Height of tower + 3m

COUNTRY ROADS 55.00 m 1.3 x Height of tower

FARM LANES, DIRT ROADS, CART TRACKS 25.00 m 10.00 m

CANALS 20.00 m 20.00 m

BUILDINGS 35.00 m 16.00 m

7.4 DESIGN CRITERIA FOR TRANSMISSION LINE IN LAO PDR

7.4.1 General

The transmission lines in Lao PDR shall be 500kV, double circuit with four conductors per phase strung on self-supporting lattice steel towers extending eastward from Hatxan substation to Lao PDR-Vietnam border, approximately 59km in length. The conductor to be used shall be 4 x 795 MCM aluminium conductors per phase, with steel reinforcement (ACSR) type. The shield wires shall be one galvanized steel wire (7/16” GSW high strength grade) and one OPGW 85 mm2 with 24 cores of optical fiber. The design, supply, construction, and installation under this portion will have to take into account the design criteria set forth below.

7.4.2 Electrical Design

The electrical characteristics of the transmission lines shall be as stated below:

Nominal system voltage 500 kV

Highest system voltage 550 kV

Rated switching impulse withstand voltage phase to earth (peak) 1,175 kV

Nominal current 3,000 A

Rated lightning impulse withstand voltage (peak) 1,550 kV

Frequency 50 Hz

Minimum insulator creepage distance 16 mm/kV

LAO PDR / VIETNAM




Rated short-time current (1 sec.) (r.m.s.) 50 kA

Maximum shielding angle to outer phase conductor 0 degree

Minimum creepage distance 8,800 mm

Minimum arcing distance phase to earth 4,234 mm

System neutral Solidity earthed

Number of circuits and conductors per phase 2 / 4

Approximate length of line 65 km

Phase to phase clearance on gantry span; without wind 4.82 m

Phase to phase clearance on gantry connection 9 m

Tower design shall provide at least the following electrical minimum clearances for insulator swinging angle:

0o TO 14o 4.00 m 14o TO 69o 1.30 m

7.4.3 Mechanical Design

The minimum factors of safety for the design of the transmission line components shall be as specified below:

Item Description Minimum Factor of Safety

1 2

All types of towers Foundation for all types of towers

See Note See Note

1

2

Insulator Strings Complete tension insulator strings and fittings at Conductor maximum working tension based on minimum breaking load of insulator Complete suspension insulator and fittings at maximum vertical load at insulator attachment point based on minimum breaking load of insulator

2.5

2.5

1 2 3

Conductors Conductors at final maximum working tension based on ultimate strength Conductors at still air everyday temperature final tension based on ultimate strength Dead end compression clamps and compression splices based on conductor ultimate strength

2.5

4.5

0.95

1 2

Shield Wires Complete tension assembly at shield wire maximum working tension Complete suspension assembly at maximum vertical load

2.5

2.5

Note: For tower and foundation, see details in Annexes of this report.

LAO PDR / VIETNAM




7.4.4 Towers

Transmission line towers shall be self-support lattice steel structure. Tower family shall include suspension towers, angle tension towers, dead end towers, and transposition towers. The towers shall be analyzed and designed in accordance with the stiffness method and shall follow all requirements of the Technical Specifications. The transmission line components shall be designed for the following main loading conditions:

a. Climatic or Weather Related Loads: Extreme Wind

b. Failure Containment Loads

c. Construction and Maintenance Loads

d. High Intensity Wind Loads Load factors and Strength factors shall be described in details in the Technical Specifications. The dimensions of the tower braces shall be such as to give the most economical structures, considering foundations and right-of-way conditions. The towers shall be designed for leg extensions of equal increments, to best conform to the variations in topography, without reducing the degree of safety. The design shall be such as to keep the number of different parts to a minimum in order to facilitate transportation, erection, and inspection. Pockets and depressions likely to hold water shall, where possible, be avoided and, if unavoidable, care shall be taken to provide an outlet to ensure proper drainage. The towers of all types and height variations shall be designed so that the stub-legs and any other members, which are erected before backfilling of the foundation hole, are firmly held in correct level and position during all field operations prior to, and including during the backfilling. Plan bracing of towers at the levels of crossarms shall be such a type to prevent the cross section of the towers from deforming from the original form under torsional loading. The included angle between any two connection stressed members shall not be less than 15 degrees.

7.4.5 Conductors

The conductors shall be Aluminium Conductor Steel Reinforced (ACSR) type Class A and meet the requirements of ASTM B232, Specification for Aluminium Conductors, Concentric-Lay-Stranded and Steel Reinforced. The complete conductors shall conform to the general characteristics as follows:

Code Name Condor

Ultimate strength (maximum tension), not less than 12,800 kg

Cross-sectional Area 795 MCM

Outside diameter (nominal) 27.72 mm

Approximate weight 1.524 kg/m

Nominal length:

Returnable metal reel 3,500 m

LAO PDR / VIETNAM




Code Name Condor

Non-returnable wooden reel 1,750 m

Standing :

Aluminium (number & diameter) 54 x 3.08 mm

Galvanised steel (number & diameter) 7 x 3.08 mm

Component Aluminium Wire :

Number 54

Diameter 3.08 mm

Elongation in 254 mm, average, not less than 1.8 %

Ultimate tensile stress, average, not less than 17.58 kg/mm2

Maximum DC resistance at 20° C 0,0719 Ohm/km

Ampacity at 75° C 852 A

Component Galvanized steel Wire :

Number 7

Diameter 3.08 mm

Elongation in 254 mm, not less than 4.0 %

Stress at 1 per cent extension, not less than 127 kg/mm2

Ultimate tensile stress, not less than 144 kg/mm2

Weight of zinc coating 259 g/m2

7.4.6 Earth Wires

The earth wires shall be galvanized steel wire strand of size 7/16 inch and conform to “High Strength” steel strand in accordance with ASTM A363, Specification for Zinc-Coated (Galvanized) Steel Overhead Ground Wire Strand. The earth wires shall have general characteristics as follow:

Material GSW (High Strength)

Cross-sectional Area 74.50sq.mm

Overall Diameter 11.11mm

Stranding 7x3.68mm

Unit Weight 0.595kg/m

Min. Ultimate Strength 6,577kg

Weight of zinc Coating 275g/m2

Reel Length 3,600m

LAO PDR / VIETNAM




7.4.7 Foundations

Foundation design shall be such that each tower is securely supported and unbalanced displacement from each tower loading condition that may cause harmful effect to the tower shall not be produced. The soil will be classified in classes for the ease in design and construction and to obtain optimum construction cost as follows:

Soil

Class

Description Density

kg/cu.m.

Angle of

Repose

NET Ultimate

Bearing Capacity kg/sq.m.

I

II

III

IV

V

R

Very Soft

Soft

Fair

Good

Hard

Solid Rock

900

1,000

1,200

1,600

1,800

1,800

0

5

15

20

30

-

-

-

25,000

50,000

75,000

>75,000 Soil class I, II, III, and S are submerged. Disintegrated rock shall be classified as soil class IV or V. The loads acting on the foundation shall be the maximum working loads determined from each tower loading condition and shall take the different leg extension of tower into account. Foundation design loads shall be calculated on the basis of the maximum axial and horizontal tower base reactions inclusive of tower overload factor and further multiplied by the factors specified above. Maximum foundation shear force from any load combination for the download leg will be assumed to act simultaneously with the maximum foundation compression force. Maximum foundation shear force from any load combination for the uplift leg will be assumed to act simultaneously.

7.4.8 Hardware and Fittings

The conductors shall be attached to the tower by insulator assemblies including hardware and fittings which shall be designed to hold the conductors under every loading condition and shall have adequate electrical strength to prevent earthing.

7.4.9 Communication System

The composite overhead ground wire with optical fibers (OPGW) shall be used as a transmission medium for communications signals and as a conventional overhead shield wire along the length of the power transmission line. Since the OPGW forms an integral part of the power transmission system, it’s electrical and mechanical performance characteristics shall be as close as possible to those of conventional overhead ground wire with respect to: sag, tension, dimension, short circuit capacity, life span, etc. The supply shall include the OPGW and all necessary accessories, including connectors, joint boxes, clamps, mounting hardware, etc. The characteristics of optical fiber and OPGW are provided in the Technical Specifications.

LAO PDR / VIETNAM




7.4.10 UXO/Mines Risks Assessment

Fig 10

In accordance with US Bombing Data from the 1960’s and 70’s, Southern Laos was one of the most heavily bombed areas. The area was extensively bombarded with cluster munitions (or Bombies as they are known), and was also the sight of extensive ground fighting. The proposed route for the transmission line begins in the most heavily bombarded area in Southern Province, and follows almost exactly the line of bombardment, which was likely to have been a wartime supply route along the ridgelines and hill tops southeast towards Vietnam. It is therefore essential that skilled companies will implement the clearance of UXO/mines to ensure a safe working environment for construction personnel. During the finalization of the angle points staking, scope of the present TA, a path finding activity was used in order to insure the safety of the surveyor. This activity did not include the disposal of the UXO; No mines field were noticed. The TL and S/S Contractor will have to use the UXO specification that is included in Annexes 2.7 or 5.8. It shall be noted that under Lao standards, as well as IMAS, there are two types of specifications, for UXO and for demining, therefore in case of mine/field this specification cannot be used. For Lao PDR, it is recommended to include UXO clearance for TL in the EPC of the contractor, in order to put the risks under the contractor responsibility. In addition it is quasi impossible in forest area to entrust this activity under the Owner responsibility. All access tracks will be cleared during construction phase. The specifications will refer to specific training, reporting to be carried out by the EOD contractor.

7.5 DESIGN CRITERIA FOR TRANSMISSION LINE IN VIETNAM

7.5.1 General

According to paragraph 7.2, final decision regarding the bidding method, has to be taken during the last tripartite meeting in Vientiane. The specifications which are included in the Volumes 4 and 5 are not adapted for an EPC contract, but are consistent with a detailed design usually included in the bidding documents for Vietnam side.

LAO PDR / VIETNAM




The transmission lines in Vietnam will be 500 kV, double circuit with four conductors per phase strung on self-supporting lattice steel towers extending southward from existing 500kV Pleiku substation in Vietnam to Lao PDR-Vietnam border approximately 93.5 km in length. The conductor to be used shall be Aluminium Conductors with Steel Reinforcement type (ACSR 330/43). The shield wires shall be one Aluminium Alloy Conductors Steel Reinforced type (AACSR-PHLOX 116.2) and one OPGW 90 with 24 cores of optical fiber. The design, supply, construction, and installation under this portion will have to take into account the design criteria set forth below.


The electrical characteristics of the transmission lines shall be as stated below:

Nominal system voltage 500 kV

Highest system voltage 550 kV

Rated switching impulse withstand voltage phase to earth (peak) 1,175 kV

Nominal current 2,000 A

Rated lightning impulse withstand voltage (peak) 11800 kV

Frequency 50 Hz

Minimum insulator creepage distance 16 mm/kV

Rated short-time current (3 sec) (rms) 40 kA

Maximum shielding angle to outer phase conductor 0 degree

Minimum creepage distance 9,135 mm

Minimum arcing distance phase to earth 4,000 mm

System neutral solidly earthed

Number of circuits and conductors per phase 2 / 4

Approximate length of line 95 km

Phase to phase clearance on gantry; without wind 10.5 m

Note1: Taken from the Norm of Electric Power Equipment, MOIT, Vietnam, 2006. However, according to the IEC this value was 1,550kV


Mechanical design of this project (for Vietnam side) shall be designed to comply with TCVN (consists of Vietnamese Standard (TCVN), Vietnamese Construction Standard (TCXDVN) and Specialized Standard (TCN)). The minimum factors of safety for the design of the transmission line components shall be as specified as follows:

Item Description Minimum Factor of

Safety 1 All types of towers See Note

LAO PDR / VIETNAM




2 Foundation for all types of towers See Note

1

2

Insulator Strings Complete tension insulator strings and fittings at Conductor maximum working tension based on minimum breaking load of insulator Complete suspension insulator and fittings at maximum vertical load at insulator attachment point based on minimum breaking load of insulator

2.7

2.7

1

2

3

Conductors Conductors at final maximum working tension based on ultimate strength Conductors at still air everyday temperature final tension based on ultimate strength Dead end compression clamps and compression splices based on conductor ultimate strength

2.5

4.0

0.95

1 2

Shield Wires Complete tension assembly at shield wire maximum working tension Complete suspension assembly at maximum vertical load

2.0 2.0

Note: For tower and foundation, see details in Annex 4.2 of this report.

7.5.4 Towers

Steel tower types of this project (for Vietnam side) shall be designed, made, and installed to comply with TCVN (consists of Vietnamese Standard (TCVN), Vietnamese Construction Standard (TCXDVN) and Specialized Standard (TCN)). Transmission line towers shall be self support lattice steel structure. Tower family shall include suspension towers, angle tension towers, dead end towers, and transposition towers. The towers shall be analyzed and designed in accordance with the stiffness method and shall follow all requirements to be specified in details in the Technical Specifications. The transmission line components shall be designed for the following main loading conditions:

a. Climatic or Weather Related Loads: Extreme Wind

b. Failure Containment Loads

c. Construction and Maintenance Loads

d. High Intensity Wind Loads Load factors and Strength factors shall be specified in details in the Technical Specifications. The dimensions of the tower braces shall be such as to give the most economical structures, considering foundations and right-of-way conditions. The towers shall be designed for leg extensions of equal increments, to best conform to the variations in topography, without reducing the degree of safety. The design shall be such as to keep the number of different parts to a minimum in order to facilitate transportation, erection, and inspection. Pockets and depressions likely to hold water shall, where possible, be avoided and, if unavoidable, care shall be taken to provide an outlet to ensure proper drainage.

LAO PDR / VIETNAM




Towers of all types and height variations shall be designed so that the stub-legs and any other members, which are erected before backfilling of the foundation hole, are firmly held in correct level and position during all field operations prior to, and including the backfilling. Plan bracing of towers at the levels of crossarms shall be such type to prevent the cross section of the towers from deforming from the original form under torsional loading. The included angle between any two connection stressed members shall not be less than 15 degrees.

7.5.5 Conductors

The conductors shall be Aluminium Conductor Steel Reinforced (ACSR) type, and meet the requirements of TCVN 5064-94 (Vietnamese Standard) equivalent to OCT 839-80 (Russian Standard). Specification for Aluminium Conductors, Concentric-Lay-Stranded, Steel Reinforced. The complete conductors shall conform to the general characteristics as follows:

Conductor type ACSR

Nominal area 330/43 mm2

Aluminium structure (No./mm) 54/2.80

Steel structure (No./mm) 7/2.80

Overall diameter 25.2 mm

Aluminium cross section 332 mm2

Overall section 375.1 mm2

Maximum DC resistance at 20oC 0.0869 Ohm/km

Minimum breaking load 10,378 daN

Approximate weight 1,255 kg/km

Current carrying capacity at 75oC 730 A

7.5.6 Earth Wires

The earth wires shall be Aluminium Alloy Conductors Steel Reinforced (AACSR) type according to the French sizes – C34 - 125. The earth wires shall have general characteristics as follow:

Code name PHLOX 116.2

Aluminium alloy area 56.55 mm2

Steel wire area 59.69 mm2

Number of Aluminium alloy wires 18

Number of steel wires 19

Diameter of wire 2 mm

Overall diameter of conductor 14 mm

Rated strength of conductor1 10,490 daN

Maximum DC resistance at 20oC 0.590 Ohm/km

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Linear mass 624 kg/km

Final modulus of elasticity 124,000 MPa

Coefficient of linear expansion 14.2 10-6 K-1

Note: 1: Calculated with steel wires of grade “extra high resistance”

7.5.7 Foundations

Foundation types of this project (for Vietnam side) shall be designed, and installed to comply with TCVN (consists of Vietnamese Standard (TCVN), Vietnamese Construction Standard (TCXDVN) and Specialized Standard (TCN)). Foundation design shall be such that each tower is securely supported and unbalanced displacement of each tower’s loading condition that may cause harmful effect to the tower is avoided. The loads acting on the foundation shall be the maximum working loads determined from each tower loading condition and shall take the different leg extensions of the tower into account. Foundation design loads shall be calculated on the basis of the maximum axial and horizontal tower base reactions inclusive of tower overload factor and further multiplied by the factors specified above. Maximum foundation shear force from any load combination for the download leg will be assumed to act simultaneously with the maximum foundation compression force. Maximum foundation shear force from any load combination for the uplift leg will be assumed to act simultaneously.

7.5.8 Hardware and Fittings

The conductors shall be attached to the tower by insulator assemblies including hardware and fittings which shall be designed to hold the conductors under every loading condition and shall have adequate electrical strength to prevent earthing.

7.5.9 Communication System

Communication system shall be designed, made, and installed to comply with TCVN (Vietnamese Standard), ITU-T, and IEC. The composite overhead ground wire with optical fibers (OPGW) shall be used as a transmission medium for communications signals and as a conventional overhead shield wire along the length of the power transmission line. Since the OPGW forms an integral part of the power transmission system, it’s electrical and mechanical performance characteristics shall be as close as possible to those of conventional overhead ground wire with respect to: sag, tension, dimension, short circuit capacity, life span, etc. The supply shall include the OPGW and all necessary accessories, including connectors, joint boxes, clamps, mounting hardware, etc. The characteristics of optical fiber and OPGW shall be provided in the Technical Specifications.

7.5.10 UXO/mines risks assessment

As shown in Fig 10 the Vietnamese side was also heavily bombed. The clearing is usually carried out separately by the army, and not included in the different contracts. On the Vietnamese side, the UXO clearing specifications will not be included in the bidding documents. The safety rules, as well as the path finding activity during survey works will also be in force. A corridor of 36 m width will be cleared, as per NPT/EVN’s practices, no additional surface is forecasted at tower locations.

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8 COST ESTIMATE FOR TRANSMISSION LINE

8.1 COST ESTIMATE FOR TRANSMISSION LINE IN LAO PDR

8.1.1 Environmental Mitigation and Monitoring

Mitigation and monitoring costs were estimated in the draft IEE. Including contingency, but excluding the erosion protection works and revegetation which is usually a part of the engineering costs, the total estimated costs for one pre-construction year, 2 construction years and 3 operating period years, including equipment costs, will be around 100,000 US$. The compensation for rubber trees is no longer considered due to the move of Hatxan S/S.

8.1.2 Construction Cost Details

In order to finalise the route, an additional detailed site visit was implemented in April 2011. It was noticed that, for the last 8km before the Border, the construction will be very difficult due to very dense forest, and steep slopes. The cost estimate was increased accordingly.

8.1.3 O&M costs in Lao PDR

The yearly O&M costs are generally equivalent to 0,8% of the construction costs, namely: 370 000 US$/Year

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8.2 COST ESTIMATE FOR TRANSMISSION LINE IN VIETNAM

8.2.1 Environmental Mitigation and Monitoring

Mitigation and monitoring costs were estimated in the draft IEE. Including contingency, but excluding the erosion protection works and revegetation which is usually a part of the engineering costs, the total estimated costs for one pre-construction year, 2 construction years and 3 operating period years, including equipment costs, will be around 100,000 US$. The compensation along the whole TL is estimated at 300,000 US$

8.2.2 Construction Cost Details

8.3 COMMENTS ON THE TRANSMISSION LINE COSTS

8.3.1 Difference between Lao PDR and Vietnam

We may notice a huge difference between the unit cost per km between Lao PDR standards, and Vietnam. The difference of cost/km between both countries is mainly due to the tonnage of towers, which is almost 50% higher in Vietnam compared to the one used in Lao PDR for a same length. Nevertheless a new design, included in this report, proposes one tension tower for 2 circuits, instead of the 2 towers proposed previously. This solution reduces considerably (by roughly 3000 tons) the total weight of towers in Vietnam, and thus the cost estimate for the TL has been reduced significantly. In addition the weight of the new suspension towers family has also

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decreased and then the new tower families have been improved and optimized, although the global tonnage per km remains higher than the one used for Lao PDR. The price is still lower in Lao PDR where the conductors are bigger than on the Vietnam side. The difference may also come from the use of several contracts instead of EPC. The lengths were adjusted for the final cost estimate, and the use of anti-theft bolts was included.

8.3.2 Technical Option

According the different meetings with all the parties it was decided the following:

8.3.2.1 Antitheft Bolts

This option will be proposed for both sides, it seems that all the parties agree to use this devices to avoid problems in the future, and which could be evaluated to 4000 US$ /km

8.3.2.2 Temporary Line

This device will not be needed as there is already a temporary line on the Vietnam side, which shall be used in case of major failure in Lao PDR under a condition to be included in a special agreement (Agreement/PPA between EVN/EDL, for example see section 13.4.5). The temporary line is specified in annex 2.1.

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9 DESIGN CRITERIA & SPECIFICATIONS FOR SUBSTATIONS

The specifications for 500kV Substations in Lao PDR and Vietnam are respectively included in annexes 2.4, and 5.4, the technical data sheets in annexes 2.5 and 5.6, and the drawings in annexes 1.4 and 4.4. In addition specifications for 500kV Underground Cables are attached in annex 5.5, in case EVN/NPT agree to install Underground Cables at Pleiku arrival in order to avoid crossing with other 500kV TL (solution strongly recommended by the Consultant). The spare parts and tools will be included in the price schedule. In addition the implementation of an Operation and Maintenance Manual will be included in the scope of works or the Contractors. The high voltage for the IPPs substations in Lao PDR will be 230kV (under IPP’s responsibility).

9.1 DESIGN CRITERIA FOR HATXAN SUBSTATION

9.1.1 General

The design criteria are reiterated in this present report. The design drawings and cost estimate are based on the technical choice which was decided during the tripartite meetings held in Hanoi and Vientiane The preferred configuration is double bus bars, with 3 Auto Transformers 600MVA. In addition a temporary situation was studied, i.e. direct connection of Xekaman 1 / Xanxay to Pleiku 230/220 kV, then avoiding in a first step the construction of the 500/230kV Hatxan S/S (only the 230/115kV S/S in Hatxan would be constructed). The Transmission Line from Hatxan to Pleiku will be in 500kV technique, but operated in 230/220 kV in the first step. The principle drawings with two stages are in annex 1.4. On the Vietnam side this step would also involves temporary works which are described in section 9.2 and annex 4.5. The financial impacts of the temporary solution are studied in chapter 12, and the impact on the system has been analyzed in chapter 11. Nevertheless this solution will be kept only in case of important delays of some associated projects, as the temporary configuration in Pleiku substation is not easy.

9.1.2 Standards

All electrical equipment shall be designed and tested according to International Electro-technical Commission (IEC) as applicable. All other design detailing and fabrication shall comply with the recommendations of the following codes and standards:

AISC AMERICAN INSTITUTE OF STEEL STRUCTURE CODE

ASCE American Society of Civil Engineers

ASME American Society of Mechanical Engineers

ASTM American Society for Testing and Materials

AWS American Welding Society

IEEE The Institute of Electrical and Electronics Engineers

NEMA National Electrical Manufacturers Association

NFPA National Fire Protection Association

NF French Standard

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TIS Thailand Industrial Standard Institute

DIN Deutches Institute fur Normung


Electrical clearances

Clearances 115kV 230kV 500kV

Minimum line-to-earth clearance 1.1 m* 1.9 m* 4.1 m*

Minimum line-to-line clearance 1.4 m* 2.45 m* 5.8 m*

Standard value for bus bar, line-to-earth clearance 1.4 m* 2.3 m* 8.0 m*

Standard value for bus bar, line-to-line clearance 2.3 m* 3.6 m* 8.0 m*

Minimum ground clearance (lower bus) 5.3 m 6.0 m 9.0 m

Minimum ground clearance (upper bus) 7.3 m 9.0 m 16.0 m Notes:

1. “*” taken from final draft of Lao Electric Power Technical Standards (LEPTS), March 26,

2003.

2. The clearance between overhead conductors (excluding cables) and their supporting structures, cross arms or guys (pole braces) shall not be less than 2700 mm even when electrical conductors sways by a wind velocity of about 20m/s.

System Data and Equipment Ratings

1. Service Condition

- Ambient Temperature (indoor) C

- Relative Humidity (indoor) %

- Ambient Temperature (outdoor) C

- Relative Humidity (outdoor) %

- 40

- 90

- 45

- Not available

2. Nominal Voltage (kV) 500 230 115

3. Maximum Voltage Rating (kV) 550* 245* 123*

4. Power Frequency (Hz) 50 50 50

5. Power Frequency Withstand Voltage (kV)

- Phase to earth and between phases

- Across open switching device and isolated distance

620

800

460

460

230

265

6. Lightning Impulse Withstand Voltage (kV)

- Phase to earth and between phases

- Across open switching devices and isolated distance

1550

1865

1050

1050

550

630

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7. Switching Impulse Withstand Voltage (kV)

- Phase to earth

- Across isolating distance

1175

1350

-

-

-

-

8. Rated Short Time Current, 1s (kA) 50* 40* 40*

9. Equipment Rated Current (A)

- Feeder

- Busbar

2000

4000

3150/2500

3150

1250

1250

10. Bus Scheme Double bus or Breaker and a half

Double bus or Breaker and a half

Main and Transfer bus

11. Pollution Level Level II moderate (16 mm/kV)

12. Auxiliary Supply

- AC

- DC (Control & Protection)

- DC (Communication)

400/230 V – 3 phase 4 wire, grounded neutral

110 V

48 V

Note: “*” TAKEN from Final Draft of Lao Electric Power Technical Standards (LEPTS), March 26, 2003


The mechanical integrity of the bus system shall be analysed using relevant standards such as IEEE or IEC to consider all the natural and unnatural mechanical forces which, from time to time, tend to disturb the mechanical integrity of the bus system. The following forces shall be applied to the conductors to verify that the designed materials would subsequently provide an effectively operating bus system.

Wind loadings

Conductor tension and sag

Tubular sag

Supporting insulator strength Most apparatus insulators are available in several mechanical strength ratings, based primarily on the cantilever strength of the insulators. The various ratings available can be found in relevant standards, such as IEC, IEEE, ANSI and NEMA, and in manufacturers’ literature. For most applications, cantilever strength is the most important mechanical characteristic. However, depending on the actual insulator application, some of the other characteristics can become important and should be considered. These insulator characteristics include tensile strength, compressive strength, and torsional strength. The design and manufacture of post-type apparatus insulators allow equal cantilever strength ratings in both upright and underhung mounting positions. Conductors of adequate ampacity and mechanical strength should be considered for bared conductor (grounding and phase conductor and OHGW) and insulated conductor. To provide protection against mechanical damage, the allowed stresses for structural members under

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mechanical loads plus emergency load shall be calculated and have a safety factor consistent with the AISC.

9.1.5 Structure

The structures shall be designed to meet the maximum of the total forces calculated vectorially from the following loadings:

Dead weight

Wind loading

Short circuit force

Seismic loading

Loads arising during assembly and erection

Vertical loading shall consist of the weight of the conductors, overhead ground wires, insulators strings, workers, the structural steel and equipment to be supported.

Wind loads on cables, towers, fittings and hardware shall be as follows:

Wind Load 500kV 230kV 115kV

Wind on projected area of structure, kg/m2 127 100 100

Wind on wire, kg/m2

Overhead ground wire

Phase conductor

85

85

67

67

67

67

Fitting and Hardware, kg/m2 85 67 67 Tensions of conductors and wires shall be in accordance with the maximum tension to be applied in theses conductors. The overload factors to be used for design are:

Item Factors based on

Normal Exceptional load (short-circuit load)

Steel structures Yield point 1.3 1.1

Tubular busses Yield point 1.5 1.1

Post insulators Failing load 2.8 1.25

String insulators Failing load 2.8 1.5

Insulator fittings Yield point 1.45 1.1

Insulator fittings of forged steel Failing load 2.25 1.25

Insulator fittings of cast iron Failing load 2.8 1.5

Foundations against compression, overturning or uprooting regardless of structure overload factors.

2.5 1.5

The strength of the compression members shall be based on the crippling loads as formula specified in ASCE Manual No. 52. The ratio of unsupported length of these to their least radius

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of gyration ("L/R ratio") shall be more than that specified. The strength of tension members is based on elastic limit. Maximum ratio of unsupported length of compression members to their last radius of gyration (L/R):

main members 150

braces and other computed stress members 200

redundant members 250

tension members 500 Maximum permissible ultimate stresses in the design of structures:

tension Fy

compression Fy

Shear bolts 0.6 Fy

Bearing on bolts 1.8 Fy Note: Fy = Yield point of the material.

9.1.6 Busbar

Busbar Scheme Two types of busbar schemes were considered for 500/230kV and 230/115kV substations.

Breaker-and-a-half scheme Double bus single breaker scheme

Breaker-and-a-Half Scheme This configuration consists of two main buses, between which connected cross buses each contain three circuit breakers. Between the first and second, and the second and third circuit breakers of each cross bus are connected transmission lines or transformers. Thus, for each two positions there are three circuit breakers, or 1 ½ circuit breakers per position. The advantages and disadvantages of this configuration are as follows: Advantages

Great operational flexibility High availability Breaker fault on the busbar side disconnects only one branch Each bus can be isolated at any time All switching operations executed with circuit-breakers Changeover switching is easy, without using isolators Busbar fault dose not lead to branch disconnections

Disadvantages

Three circuit-breakers required for two branches, resulting in overcost Greater outlay for protection and auto-reclosure, as the middle breaker must respond

independently in the direction of both feeders

Double Bus Single Breaker Scheme This configuration consists of two main buses, with each line or transformer circuit breaker is connected to both main buses through disconnect switches. This feature allows loads and

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sources to be equally distributed between both main buses, and allows all lines and transformers to be connected to one bus if the other must be de-energized. This configuration includes at least one coupling bay. The advantages and disadvantages of this configuration are as follows: Advantages

High changeover flexibility with two busbars of equal merit Each busbar can be isolated for maintenance Each branch can be connected to each bus with tie breaker and BB isolator without

interruption Disadvantages

Extra breaker for coupling Bus bar protection disconnects all branches on the affected busbar Fault at tie breaker causes complete station outage

Main and Transfer Bus Scheme This configuration consists of one main bus to which all lines and transformers are connected with circuit breakers. There is a transfer bus connected to the main bus through a transfer circuit breaker. Each line and transformer is connected to the transfer bus through a disconnect switch. Under normal operating conditions, all lines and transformers are connected to the main bus. This configuration is normally used for 115kV substations. Busbar Scheme Selection Double bus single breaker is particularly suitable for highly interconnected power networks in which switching flexibility is important and multiple supply routes are available. However this scheme also gives no security against busbar faults and needs to be sectionalised to limit their effects. Breaker-and-a-half is particularly suitable for important substations handling large amounts of power, such as those associated with generating stations. This scheme also gives high security against busbar faults and involves minimum outage for maintenance. All of the bus schemes compared have advantages and disadvantages. It appears that increasing reliability by provision of alternative feeds increases the cost substantially. Therefore, the double busbar single breaker scheme is recommended for 500/230kV and 230/115kV Hatxan Substation based on the comparison price and area while for 115/22kV substation, main and transfer bus is recommended to meet EdL standard. Type of Busbar The busbars will be of the rigid type and the strain type. In the rigid type bus bars, aluminium tubes are used for bus-bars and also for making connections among the various equipments wherever required. The bus-bars and the connections are supported on station post insulators. This leads to a low level type of switchyard wherein equipment as well as the bus-bars are spread out. Since the bus-bars is rigid, the clearances remain constant. However as the bus-bars and connections are not very high from the ground, the maintenance is easy. Due to large diameter of the aluminium tubes, the corona loss is also substantially less. It is also claimed that this system is more reliable than the strain bus.

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The strain type bus bars are an overhead system of wires strung between two supporting structures and supported by suspension insulators. This strain bus will be used to connect with the transmission lines and tap-off to the equipment.

Description 500kV substation 230kV substation 115kV substation

Type Tubular bus and strain bus

Tubular Size

Main Bus

Branch Bus

5 inch IPS

5 inch IPS

5 inch IPS

5 or 3 inch IPS

3 inch IPS

3 inch IPS

Aluminium schedule Schedule 40, 6063 T6 Alloy

Conductor size

Strain bus

Between equipment

4x795 MCM ACSR

4x795 MCM ACSR

4x795 MCM ACSR

4x795 MCM ACSR

1x795MC MACSR

1x795 MCM ACSR

Cantilever strength of station post insulators

10 kN 8 kN 8 kN

The maximum vertical deflection of aluminium tube bus shall not exceed 1/200th of the span or one bus diameter whichever is greater. The corona-free bus fittings will be specified at the connections to the equipment. Where the configurations require additional shielding, corona rings and shells are included with the particular connectors.

9.1.7 Circuit Breakers

Circuit breakers will be SF6 gas, single pressure puffer type, live tank design and spring type. The continuous current rating of 2000 A will be established for 500kV circuit breaker to meet the line circuit breaker from Vietnam.

Description 500kV substation

230kV substation

115kV substation

1. Type SF6 Gas, outdoor, live-tank, single pressure

2. Rated Voltage (kV) 525 245 123

3. Maximum System Voltage (kV) 1550 1050 550

4. Number of Interrupter per Pole 2 1

5. Rated Frequency (Hz) 50

6. Rated normal current (A) 2000 3150 1250

7. Rated short time withstand current (kA) 50 40 31.5

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Description 500kV substation

230kV substation

115kV substation

8. Making Capacity (kA peak) 125 100 78.75

9. Breaking Time (cycles) 2 2 3

10. Operating mechanism Spring

11. Operating sequence O+0.3s+CO+1min-CO O+0.3s+CO+3min-CO

12. Type of tripping

- Line bay

- Transformer bay

- Single-pole & Three-pole

- Single-pole & Three-pole

- Single-pole

- Three-pole

13. DC supply

- Rated Control Circuit Voltage (VDC)

- Tripping Circuit, min-max (VDC)

- Closing Circuit, min-max (VDC)

- 110

- 85-110 % of VDC

- 85-110 % of VDC

14. Applicable Standard IEC60056 & IEC60694

9.1.8 Transformers

The 500/230-22 kV and 230/115-22 kV transformers shall be autotransformers, oil filled conservator type and 115/22-22 kV transformer shall be three-phase transformer, oil filled conservator type. The 500/230-22 kV autotransformers shall be single phase because of the large physical sizes of three phase EHV (Extra High Voltage) autotransformers. The large size makes them more difficult to transport to the site. It is much cheaper and easier to stock a spare single phase unit than a three phase unit, if required.


Type Outdoor, Single-phase, Auto-transformer, Oil-filled, conservator type with OLTC

Outdoor, Three-phase, Auto-transformer, Oil-filled, conservator type with OLTC

Outdoor, Three-phase, Three windings transformer, Oil-filled, conservator type with OLTC

Rated Frequency (Hz) 50

Rated Voltage (kV)

- HV

- LV

- TV

- 525/3

- 245/3

- 22

- 230

- 115

- 22

- 115

- 22

- 22

Highest System Voltage (kV)

- HV

- LV

- 550

- 245

- 245

- 123

- 123

- 24

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- TV - 24 - 24 - 24

Class ONAN/ONAF/ONAF ONAN/ONAF

Rated Capacity (MVA)

- HV

- LV

- TV

120/160/200

120/160/200

5.6/7.5/10

- 56/70

- 56/70

- 18.6/23.3

- 16/20

- 16/20

- 5.3/6.6

BIL (kV)

- Winding HV/LV/TV/Neutral

- Bushing HV/LV/TV/Neutral

-1,550/1,050/125/ 125

-1,550/1,050/125/ 125

-1,050/550/125 /125

-1,050/550/125 /125

-550/125/125

-550/125/125

Winding Connection in Three-phase

YN yn0,d1 YN yn0,d1 YN yn0,d1

On Load Tap Changer (Rated Voltage Base)

525/3 10%

x1.25 % Step

230 10%

x1.25 % Step

115 10% x1.25 % Step

Winding Insulation Temperature Class (°C)

120 120 120

Surge Arrester (Tank Mounted Type)

- HV Side

- LV Side

- TV Side

- None

- 192 kV

- 21 kV

- 192 kV

- 96 kV

- 21 kV

- 96 kV

- 21 kV

- 21 kV

Bu Bushing Current Transformers

- HV Side

- LV Side

- TV Side

- Neutral Side

- 2-core

- 2-core

- 2-core

- 2-core

- 2-core

- 2-core

- 2-core

- 2-core

- 2-core

- 1-core

- None

- None

The tertiary winding rating is selected to be 33% of the main winding rating. The tertiary winding rating must be large enough so that it is not damaged by zero sequence phase fault currents circulating in the transformer tertiary winding from a line to ground fault at the transformer terminals. The 33% rating is an industry standard. It may be possible to use a smaller rating if there is a significant economic advantage to do so. A common control cubicle (CCC) will be provided by the supplier of 500/230-22 kV autotransformer. The CCC is for interfacing between individual single phase transformer control cabinet and remote control and protection system. For three-phase power transformer, power transformer marshalling cubicle (PMC) is required for the interfacing between the three-phase power transformer and remote control and protection system.

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9.1.9 Auxiliaries

AC Auxiliary

500/230 & 230/115kV Substations:

AC power shall ultimately be supplied from 2 completely independent sources. No single contingency should result in an outage of both AC power sources. Automatic switchover from the primary source to the secondary source shall be provided when the primary source if lost. AC auxiliary power shall be furnished from a 22 kV source connected to a 22/0.4-0.23kV delta-wye ground station service transformer. A station service transformer shall ultimately be furnished for each of the primary and secondary sources of auxiliary power. The automatic transfer switch shall be furnished on the 0.4-0.23kV system. The primary source of AC auxiliary power shall be the 22kV tertiary winding of one of the 500/242-22kV autotransformers. The secondary source shall be 22kV tertiary winding of one of the 230/115-22kV autotransformers. Two 22kV buses shall each have the capability of furnishing station service power if one or the other is out of service.

115/22 kV Substation:

The primary source of AC power at 115kV substation shall be 22kV tertiary winding of one of the 115/22-22kV power transformers. The secondary source of AC power at 115kV substation shall be a 22kV feeder from EDL. When 500kV substation is installed, the station service will be supplied from 22kV tertiary winding of the 525/242kV Autotransformer. The 22kV power cable will be run from this autotransformer and connected to the existing 22kV switchgear in control building.

DC Auxiliary All 500/230kV, 230/115kV and 115/22kV substations shall be furnished with two 48 VDC and two 110 VDC batteries and battery chargers for control and protective relaying. These batteries shall be installed in the control building and relay house. The 110 VDC batteries shall be utilized for DC control and protection requirements in the control room, relay house and switchyard. In case the circuit breaker has two tripping coils, one battery will be used for circuit breaker closing, one circuit breaker trip circuit and motor operated disconnecting switch operation. The other battery is used for the second circuit breaker trip circuit. The 48 VDC batteries shall be utilized for communication equipment.

9.1.10 Civil Works

Sub-soil investigation Sub-soil investigation shall be performed by means of boreholes to determine the physical and chemical characteristics of the various strata and of the groundwater, if encountered. All tests, both field and laboratory will be carried out to the ASTM standards. The boring will terminate to the stiff layer.

Site work

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The new Hatxan S/S location is not adapted for a substation construction, such as the previous location at km 27. In fact, due to the presence of two creeks, and a level difference of 17 meters, the important works of levelling, compacting and sustaining are necessary. In addition due to the natural constraints, it was not possible to locate the 16ha necessary for the whole substation within the 100 ha allocated by the local Authorities. As a consequence, the Consultant has requested an additional 10 ha from the Ministry of Mines in order to place the switchyard in the best conditions. Further study would be required to determine whether sustainable structures are needed to maintain the platform which will be at a level of 165m.

Drainage system The drainage system will drain all the storm run-off water and all other water by using a pipe sump and open gutter system to a drainage pit outside switchyard area in accordance with rural or any Lao government acts or regulations. A surface drainage system is required for flat yard. This consists of a gently sloping (0.5% to 0.75%) ground surface so that the water drains to the edge of the yard or to shallow ditches within the yard. A rainfall intensity of 100 mm/hr continuous will be assumed if site specific data is not available. Gravity flow with velocity of 0.75-1.50 m/s will be specified. The coefficient of run-off of 0.5 will be used except 0.90 for roads and 0.70 for switchyard. The yard surface drainage must be coordinated with the location of cable trenches and roads within the yard.

Earth work The computation of earth work quantities is usually the first step toward establishing the nominal rough grade elevation of the yard. Clearing and grubbing of the site is required and all vegetation should be removed and properly disposed off. Earth filling is required in order to increase the substation finished grade to be higher than 0.50 m from flood level and or rural road level. Adequate compaction during placement of the fill is necessary to develop the required soil bearing capacity and lateral resistance for the foundation design. It is necessary also to prevent settlement due to consolidation of the embankment which may result in ponding, broken ducts, conduits, cable trenches, etc. All fill areas should be compacted in 200 mm layers to 95% of the maximum density obtained by AASHTO-99, where the entire yard is assumed to be used as a driving surface. Upon completion of the earth work, all excavated earth not used in backfilling should be leaved off or shaped to present a neat appearance and not obstruct any drainage.

Substation surfacing It is desirable to have 100 mm of 1 ½ to 2 ½ inch size crushed rock covering the entire substation yard and extending 1.5 m beyond the substation fence.

Security fence The entire substation area will be enclosed by a barbed wire fence. This fence should be installed as soon as possible after the site work is complete.

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The wire-mesh fence should cover the switchyard area including switchyard equipment and control and relay building. The wire-mesh fence should be galvanized steel fence. An entrance gate should be installed for main entrance of each substation.

Fire wall The firewalls shall be furnished for each transformer to protect adjacent transformers from damage due to a fire. The fire wall will be reinforced concrete. The fire walls will have at least 1.2 m of clearance to any part of the transformer and will be located such that transformer maintenance, transformer removal and transformer cooling, is not impaired.

Oil containing pits and oil separators The oil containing pits will be furnished around the transformer and shunt reactor foundations to prevent during oil spreading from the vicinity of the damaged transformer or reactor. Oil and water will be quickly drained from oil containing pits to the oil separators. The oil containing pit will be furnished with a steel grate, located near the top. The steel grate will be filled with at least 150 mm of 3 to 4 inch size crushed rock. The bottom of the pit will be sloped to a drain pipe leading to an oil separator. The oil containing pit will have sufficient volume for storing the entire quantity of oil from any transformer and reactor plus conservator and radiators of transformer and reactor. The oil containing pit will be furnished with curbing around the outside to keep surface water out. The oil separator volume will be governed by the transformer or reactor with the largest volume of oil in the substation.

Foundations The selection of the type of foundation will depends on loads and configuration, soil, foundation and site conditions and material, labor and equipment costs. All of this comes down to selecting a foundation type that performs the required function for the least cost.

Cable trench Cable trench with cover will be a reinforced concrete trench with hot dip galvanised steel cable hangers attached to the sides. The hanger galvanizing should be a minimum of 70 µm (minimum zinc coat 460 gm/m2). The cable trench cover should be a steel plate with steel frame and should be galvanized. The cover loading should be per AASHTO H20-S16.

Road The road should be reinforced concrete road. The width of 5.00 and 3.00 m should be specified and the curve radius should be 12.00 m for 5.00 m wide.

The road for transportation by lorry of the transformer or reactor shall be 5.00 m wide.

Water supply Water supply for serving kitchen, toilets and washrooms in the substation buildings will be supplied from deep well.

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An overhead water tank with sufficient pressure for all water consumers will be provided for the water supply system. The capacity of the tank shall be more than 4.0 m3 and it should be made of plastic or glass fibre. The tank should be installed on a self-standing separate tower.

Fire Protection Portable fire extinguishers will be installed in the 500/230kV control building, 115kV control building, relay house, operator’s house and storage building. The mobile fire extinguisher will be installed in the fire extinguisher house. This house will be painted in red and located not further than 40m from the transformer yard. The fire alarm system will be provided in the control room of the control building and relay house of each substation.

Control Building The two control buildings are for installing control and communication equipment including auxiliary system, one for 500kV and 230kV substation and another one for 115 kV equipment plus 230/115kV transformer bays. Each building will also consist of a control room, office room, meeting room, pantry, rest room and battery room. The control and relay building should be constructed for a long life and should include minimum maintenance. They should be provided with facilities such as interior lighting, ventilation and air conditioning.

Relay House The relay panels will be installed in the relay house which will be located between two bays of 500kV and 230kV substations, as central as possible, to minimize the circuit length of cables to electrical equipment. The relay house shall be constructed for long life and minimum maintenance and be provided with a battery room and facilities such as interior lighting, ventilation and air condition.

0perator’s House Operator’s houses are required for operators of 500kV, 230kV and 115kV substations. An operator’s house should be two stories and include at least a living room, bed room, kitchen and toilet.

Storage Building The storage building will be used for storing spare parts of equipment for each substation.

Guard House The guard house will be located close to the main gate of each substation.

9.1.11 Protection Policy

The provision of protection system is to detect and disconnect elements of the power system in the event of faults to minimize any risk to life and/or property. Protective relays and their associated hardware and software for a complete use shall be provided with the following functions as a minimum:

1. Busbar protection

2. Transmission line protection

3. Shunt reactor protection

4. Transformer protection

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5. Breaker protection

In order to conform to the 500kV Pleiku Substation of Vietnam, main relays shall be numerical type, IEC61850 standard for communication protocol between host computers and IEDs, intelligent electronic devices with the functionality installed devices in the relays:

Protective relays

Measuring devices

Metering devices

Control devices

Monitoring devices

Disturbance recorders

Event recorders

Power quality monitoring devices

Remote terminal units Energy meters with complete components for measuring and recording of the active energy and reactive energy at the 500kV transmission lines, 500/230kV power transformer bays, 230kV transmission lines and 115kV transmission lines shall be provided separately from the relays. Control and monitoring of substation equipment can be performed via:

Numerical relays

Supervisory control and data acquisition (SCADA) The SCADA shall include all hardware, software and telecommunication facilities necessary to meet the minimum features:

Monitoring and control of the equipment

Analog value processing

System database management

Event and alarm handling

One line diagram with busbar coloring

Trend curves

Interlocking

Reporting and printing

Global Positioning System (GPS)

Monitoring of power quality

Remote relay setting

Uploading and evaluation of disturbance record files

Multi-level user authorization

Interface to remote SCADA

System supervision

Modification to client-specific requirement such as displays, grouping, reporting etc.

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9.1.12 Telecommunication

1. Communication media between 500kV Hatxan Substation in Lao PDR and 500kV Pleiku Substation in Vietnam shall be as follows:

Overhead Ground Wire with Optical Fibers (OPGW)

Power line carrier (PLC)

2. The following standard shall be applied:

IEC61850 : Communication networks and system in substation for communication between SCADA and intelligent electronic devices (IEDs) or network interface modules (NIM)

IEC60870-5-101 : Telecontrol equipment and systems for communication between substation real-time database to the existing SCADA system of Vietnam

3. Communication equipment are as follows:

3.1 Power Line Carrier shall consist of:

o Transceiver to transmit and/or receive signals

o Coaxial cable for connection between terminal and coupling device

o Coupling device or line matching unit or line tuning unit for separating terminal equipment and power line

o Coupling capacitor for coupling signals into the transmission line

o Line trap for blocking the carrier signal back to substation

3.2 Teleprotection equipment for intertripping to the remote shall be capable of simultaneously transmitting and receiving signals between the line protective relays provided at each substation. The line protective relays shall be divided into two types. One can be used for direct and permissive transfer trip scheme. The other can be used for blocking and unblocking scheme.

3.3 Multiplexer shall consist of:

o 4 Wire E & M voice frequency module

o 2 Wire voice frequency module for PABX

o V.11 synchronous data module

o RS232 asynchronous data module

o 64 Kbps ITU-T Rec. G.703 for teleprotection equipment

3.4 Private automatic branch exchange (PABX) for voice communication

3.5 Optical line terminal equipment (OLTE) shall be designed to handle time sensitive application such as protective relaying and shall be designed for back-to-back and drop-and-insert equipment.

3.6 Optical distribution frame (ODF) shall be suitable and large enough to accommodate the connection of all optical fiber and fiber cord leading to OLTE.

The communication block diagram for this project can be shown as follows

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9.1.13 Hatxan S/S Single line Diagram

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9.1.14 Hatxan S/S Layout (Phase 1)

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9.1.15 Hatxan S/S Layout (Phase 2) or Final Phase

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9.2 DESIGN CRITERIA & SPECIFICATION FOR PLEIKU SUBSTATION EXTENSION

9.2.1 General

The high voltage for the IPPs substations will be 230kV. All electrical equipment shall be designed and tested according to International Electro-technical Commission (IEC) as applicable. All other design detailing and fabrication shall comply with the recommendations of the following codes and standards:

AISC American Institute Of Steel Structure Code

ASCE American Society of Civil Engineers

ASME American Society of Mechanical Engineers

ASTM American Society for Testing and Materials

AWS American Welding Society

IEEE The Institute of Electrical and Electronics Engineers

NEMA National Electrical Manufacturers Association

NFPA National Fire Protection Association

IEC International Electrotechnical Commission

TCVN Vietnamese Standard (TCVN), Vietnamese Construction Standard (TCXDVN) and Specialized Standard (TCN) and EVN regulations

DIN Deutsches Institute fur Normung


Electrical clearances

Clearances 220kV 500kV

Minimum line-to-earth clearance 12.1 m 14.1 m

Minimum line-to-line clearance 12.1 m 17.4 m

Standard value for bus bar, line-to-earth clearance 14.35 m 16.35 m

Standard value for bus bar, line-to-line clearance 14.35 m 16.35 m

Minimum ground clearance (lower bus) 212.0 m 220.0 m

Minimum ground clearance (upper bus) 219.0 m 228.0 m

NOTES:

“1” taken from Norm of Electric Power Equipment, MOIT, Vietnam, 2006.

“2” elevation taken from insulator suspension point at gantry.

System Data and Equipment Ratings

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1. Service Condition

Maximum Ambient Temperature (indoor) C

Average Relative Humidity (indoor) %

Maximum Ambient Temperature (outdoor) C

Relative Humidity (outdoor) %

39

78.4

44

Not available

2. Nominal Voltage (kV) 500 220

3. Maximum Voltage Rating (kV) 550 245

4. Power Frequency (Hz) 50 50

5. Power Frequency Withstand Voltage (kV)

Phase to earth and between phases

Across open switching device and isolated distance

710(680)

800

460(460)

530

6. Lightning Impulse Withstand Voltage (kV)

Phase to earth and between phases

Across open switching devices and isolated distance

1,800 (1,550)

1,865

1,050

1,200

7. Switching Impulse Withstand Voltage (kV)

Phase to earth

Across isolating distance

1,175

1,350

-

-

8. Rated Short Time Current, 3s (kA) 40 40

9. Equipment Rated Current (A)

Feeder

Busbar

2,000

4,000

2,000

4,000

10. Bus Scheme Breaker-and-a-half Double bus, single breaker with bypass bus

11. Pollution Level Level II moderate (20 mm/kV)

12. Auxiliary Supply

AC

DC (Control & Protection)

DC (Communication)

400/220 V – 3 phase 4 wire, grounded neutral

220 V

48 V

Note: xxx(xxx) where

“xxx” : taken from Norm of Electric Power Equipment of MOIT, Vietnam, 2006.

“(xxx)” : Taken from IEC


The mechanical integrity of bus system shall be analyzed using relevant standards such as TCVN (Vietnamese Standard), IEC or IEEE to consider all the natural and unnatural mechanical forces which, from time to time, tend to disturb the mechanical integrity of the bus system. The following forces shall be applied to the conductors to verify that the designed materials would subsequently provide an effective operating bus system.

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Wind loadings

Conductor tension and sag

Tubular sag

Supporting insulator strength Most apparatus insulators are available in several mechanical strength ratings, based primarily on the cantilever strength of the insulators. The various ratings available can be found in relevant, such as IEC, IEEE, ANSI and NEMA standards and in manufacturers’ literature. For most applications, cantilever strength is the most important mechanical characteristic. However, depending on the actual insulator application, some of the other characteristics can become important and should be considered. These insulator characteristics include tensile strength, compressive strength, and torsional strength. The design and manufacture of post-type apparatus insulators allow equal cantilever strength ratings in both upright and under hung mounting positions. Conductors of adequate ampacity and mechanical strength should be considered for bared conductor (grounding and phase conductor and OPGW) and insulated conductor provide protection against mechanical damage. The allowable stresses for structural members under mechanical loads plus emergency load shall be calculated and have the factor of safety according to the AIS.

9.2.4 Structure

Structure shall be designed to comply with TCVN (consists of Vietnamese Standard (TCVN), Vietnamese Construction Standard (TCXDVN) and Specialized Standard (TCN)). The structures shall be designed to meet the maximum of the total forces calculated vectorially from the following loadings:

Dead weight

Wind loading

Short circuit force

Seismic loading (just consider for cases of seven on the Richter scale or more)

Loads arising during assembly and erection

Vertical loading shall consist of the weight of the conductors, overhead ground wires, insulators strings, workers, the structural steel and equipment to be supported.

Wind loads on cables, towers, fittings and hardware shall be as follows:

Wind Load 500kV 220kV

Wind on projected area of structure, kg/m2 127 100

Wind on wire, kg/m2

Overhead ground wire

Phase conductor

85

85

67

67

Fitting and Hardware, kg/m2 85 67 Tensions of conductors and wires shall be in accordance with the maximum tension to be applied in theses conductors.

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The overload factors to be used for design are: Item Factors based on Normal Exceptional load

(short-circuit load)

Steel structures Yield point 1.3 1.1

Tubular busses Yield point 1.5 1.1

Post insulators Failing load 2.8 1.25

String insulators Failing load 2.8 1.5

Insulator fittings Yield point 1.45 1.1

Insulator fittings of forged steel Failing load 2.25 1.25

Insulator fittings of cast iron Failing load 2.8 1.5

Foundations against compression, overturning or uprooting regardless of structure overload factors.

2.5 1.5

The strength of the compression members shall be based on the crippling loads as formula specified in TCXDVN 338:2005 (Vietnam Construction Standard). The ratio of unsupported length of these to their least radius of gyration ("L/R ratio") is more than that specified. The strength of tension members is based on elastic limit. Maximum ratio of unsupported length of compression members to their least radius of gyration (L/R):

main members 120

braces and other computed stress members 150200

redundant members 250

tension members 250350

Maximum permissible ultimate stresses in the design of structures:

tension Fy

compression Fy

Shear bolts 0.6 Fy

Bearing on bolts 0.6 Fy

Note: Fy = Yield point of the material.

9.2.5 Busbar

Busbar Scheme Busbar Schemes of the existing 500kV Pleiku S/S for 500kV and 220kV voltage levels as below:

Breaker-and-a-half scheme for 500kV busbar

Double bus, single breaker with bypass bus scheme for 220kV busbar So, breaker-and-a-half scheme shall be used for 500kV busbar scheme and Double bus, single breaker with bypass bus scheme shall be used for 220kV busbar scheme in this project. Type of Busbar The busbars will be of the rigid type and the strain type.

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In the rigid type bus bars, aluminium tubes are used for bus-bars and also for making connections among the various equipments wherever required. The bus-bars and the connections are supported on station post insulators. This leads to a low level type of switchyard wherein equipment as well as the bus-bars are spread out. Since the bus-bars are rigid. The clearances remain constant. However as the bus-bars and connections are not very high from the ground, the maintenance is easy. Due to large diameter of the aluminium tubes, the corona loss is also substantially less. It is also claimed that this system is more reliable than the strain bus. The strain type bus bars are an overhead system of wires strung between two supporting structures and supported by suspension insulators. This strain bus will be used to connect with the transmission lines and tap-off to the equipment.

Description 500kV 220kV

Type Tubular bus and strain bus

Tubular Size Aluminium-Φ160/150

Conductor size 3xAAC 805 2xAAC 885

Cantilever strength of station post insulators 10 kN 8 kN The maximum vertical deflection of aluminium tube bus shall not exceed 1/200th of the span or one bus diameter whichever is greater. The corona-free bus fittings will be specified at the connections to the equipment. Where the configurations require additional shielding, corona rings and shells are included with the particular connectors.

9.2.6 Circuit Breakers

Circuit breakers will be SF6 gas, single pressure puffer type, live tank design and spring type. The continuous current rating of 2000 A will be established for 500kV circuit breaker to meet the line circuit breaker from Vietnam.


Type SF6 Gas, outdoor, live-tank, single pressure

Rated Voltage (kV) 550 245

Lightning Impulse Withstand Voltage (kV) Phase to earth and between phases

1800(1550) 1050(1050)

Number of Interrupter per Pole 2

Rated Frequency (Hz) 50

Rated normal current (A) 2000 2000

Rated short time withstand current (kA/s) 40 40

Making Capacity (kA peak) 100 80

Maximum Breaking Time (ms) 80 100

Operating mechanism Spring

Operating sequence O+0.3s+CO+1min-CO

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Type of tripping

Line bay

Transformer bay

Single-pole & Three-pole

Three-Pole

DC supply

Rated Control Circuit Voltage (VDC)

Tripping Circuit, min-max (VDC)

Closing Circuit, min-max (VDC)

220

85-110 % of VDC

85-110 % of VDC

Applicable Standard IEC 62271-100, etc…

Note: xxx(xxx) where

“xxx” : taken from Norm of Electric Power Equipment of MOIT, Vietnam, 2006.

“(xxx)” : Taken from IEC

9.2.7 Auxiliaries

AC Auxiliary 220/380V AC auxiliaries will be used the existing AC power system of Pleiku S/S and will be supplemented some MCBs.

DC Auxiliary 220VDC and 48VDC auxiliaries will be used the existing DC power systems of Pleiku S/S and will be supplemented some MCBs. The 220 VDC batteries shall be utilized for DC control and protection requirements in the control room, relay house and switchyard. In case the circuit breaker has two tripping coils, one battery will be used for circuit breaker closing, one circuit breaker trip circuit and motor operated disconnecting switch operation. The other battery is used for second circuit breaker trip circuit. The 48 VDC batteries shall be utilized for communication equipment.

9.2.8 Civil Works

Sub-soil investigation Sub-soil investigation shall be performed by means of boreholes to determine the physical and chemical characteristics of the various strata and of the ground water, if encountered. All tests, both field and laboratory will be carried out to the TCXDVN (Vietnamese Construction standard). The boring will terminate to the stiff layer.

Site work The site work should provide an easily accessible, dry, maintenance free area for installation and operation of electrical substation equipment and structures.

Pleiku substation extension area is flat yard which is more desirable for the layout and operational function of the substation. This type of yard permits uniformity in foundation elevations and structure heights.

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Drainage system The drainage system exists in Pleiku S/S.

Earth work The computation of earth work quantities is usually the first step toward establishing the nominal rough grade elevation of the yard. Clearing and grubbing of the site is required and all vegetation should be removed and properly disposed off. Earth filling is required in order to increase the substation finished grade to be higher than 0.50 m from flood level and or rural road level. Adequate compaction during placement of the fill is necessary to develop the required soil bearing capacity and lateral resistance for the foundation design. It is also necessary to prevent settlement due to consolidation of the embankment which may result in ponding, broken ducts, conduits, cable trenches, etc. All fill areas should be compacted 250 mm layers to 95% of the maximum density obtained by TCVN 4447-1987 (Vietnamese Standard), where the entire yard are assumed to be used as a driving surface. Upon completion of the earth work, all excavated earth not used in backfilling should be leaved off or shaped to present a neat appearance and not obstruct any drainage. Substation surfacing It is desirable to have 100 mm of 1 ½ to 2 ½ inch size crushed rock cover the entire substation yard and to extend 2.0 m beyond the substation fence. Security fence The entire substation area shall enclosed by a brick wall fence. This fence should be installed as soon as possible after the site work is complete. The entrance gate should be installed for the main entrance of each substation. Oil containing pits and oil separators Oil containing pits will be furnished around the transformer and shunt reactor foundations to prevent during oil spreading from the vicinity of the damaged transformer or reactor. Oil and water will be quickly drained from oil containing pits to the oil separators. Oil containing pit will be furnished with a steel grate, located near the top. The steel grate will be filled with at least 250 mm of 3 to 4 inch size crushed rock. The bottom of the pit will be sloped to a drain pipe leading to an oil separator. The oil containing pit will have sufficient volume for storing the entire oil from any transformer and reactor plus conservator and radiators of transformer and reactor. The oil containing pit will be furnished with curbing around the outside to keep surface water out. The oil separator volume will be governed by the transformer or reactor with the largest volume of oil in substation.

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Foundations The selection of type of foundation will depends on loads and configuration, soil, foundation and site conditions and material, labor and equipment costs. All of this comes down to selecting a foundation type that performs the required function for the least cost. Cable trench Cable trench with cover will be reinforced concrete trench with hot dip galvanized steel cable hangers attached to the sides. The hanger galvanizing should be a minimum of 80 µm. The cable trench cover should be steel plate with steel frame and should be galvanized. Road The road should be reinforced concrete road. The width of 6.00 and 4.00 m should be specified and the curve radius should be 12.00 m for 6.00 m wide. The road for transportation by lorry of the transformer or reactor shall be 6.00 m wide. Water supply Water supply system will be used for existing water supply system of Pleiku S/S. Fire Protection Fire Protection system will be used for existing Fire Protection system of Pleiku S/S Control Building Control Building will be used for existing Control Building of Pleiku S/S. Relay House Relay House will be used for existing Relay House of Pleiku S/S. Operator’s House Operator’s House will be used for existing Operator’s House of Pleiku S/S. Storage Building Storage Building will be used for existing Storage Building of Pleiku S/S. Guard House Guard House will be used for existing Guard House of Pleiku S/S

9.2.9 Protection Policy

The protection policy shall comply with the EVN’s regulation. The protection policy shall follow all requirements to be specified in details in the Technical Specifications (for the next design stage). The provision of a protection system is to detect and disconnect elements of the power system in the event of faults to minimize any risk to life and/or property. Protective relays and their

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associated hardware and software shall be provided with the following minimum safety functions:

Busbar protection

Transmission line protection

Shunt reactor protection

Breaker protection In order to conform to the new 500kV S/S of Vietnam, main relays shall be numerical type, IEC61850 standard for communication protocol between host computers and IEDs, intelligent electronic devices with the functionality installed devices in the relays:

Protective relays

Measuring devices

Metering devices

Control devices

Monitoring devices

Disturbance recorders

Event recorders

Power quality monitoring devices

Remote terminal units Energy meters with complete components for measuring and recording of the active energy and reactive energy at the 500kV transmission lines, and 220kV transmission lines shall be provided separately from the tariff meter. Control and monitoring of substation equipment can be performed via:

Numerical relays

Supervisory control and data acquisition (SCADA) The SCADA shall include all hardware, software and telecommunication facilities necessary to meet the minimum features:

Monitoring and control of the equipment

Analog value processing

System database management

Event and alarm handling

One line diagram with busbar coloring

Trend curves

Interlocking

Reporting and printing

Global Positioning System (GPS)

Monitoring of power quality

Remote relay setting

Uploading and evaluation of disturbance record files

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Multi-level user authorization

Interface to remote SCADA

System supervision

Modification to client-specific requirement such as displays, grouping, reporting etc.

Policy of Control and Protection System Metering System Inputs for control and protection system:

Current (A)

Voltage (V)

Power (MW & MVAr)

Energy (MWh & MVArh)

Frequency (Hz)

Power factor

Control system

Control via numerical relays

Computerized control system (CCS: main and back-up)

Control via hard-wire logic at bay level Control of Equipment

Breaker (ON/OFF)

DS/ES (Close/Open)

Transformer (Raise/Lower, Temp.) Protection System Protection functions are listed below:

1) Busbar protection

Differential protection (F87B)

2) Line protection Differential protection (F87L) Distance protection (F21/21N) Directional overcurrent protection (F67/67N) Overcurrent protection (F50/51, F50/51N) Over/under voltage protection (F27/59) Negative sequence/Broken conductor (F46) Overload protection (F51L) Autoreclosing relay (F79) Synchronism check relay (F25)

3) Shunt reactor protection

Differential protection (87R) Overcurrent protection (F50/51, F50/51N)

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Negative sequence protection (F46) Overload protection (F51L)

4) Breaker protection

Breaker failure protection (F50BF) Trip circuit supervision relays (F74) Pole Discrepancy relay (PD)

9.2.10 Telecommunication

1) Communication media between 500kV Bansok (Hatxan) Substation in Lao PDR and 500kV Pleiku Substation in Vietnam shall be as follows:

o Overhead Ground Wire with Optical Fibers (OPGW)

o Power line carrier (PLC)

2) The following standard shall be applied:

o IEC61850 : Communication networks and system in substation for communication between SCADA and intelligent electronic devices (IEDs) or network interface modules (NIM)

o IEC60870-5-101 : Telecontrol equipment and systems for communication between substation real-time database to the existing SCADA systems of Vietnam (National Load Dispatch Center (NLDC) in Hanoi City and Central Regional Load Dispatch Center (CRLDC) in Danang City).

3) Communication equipment is as follows:

3.1. Power Line Carrier shall consist of:

o Transceiver to transmit and/or receive signals

o Coaxial cable for connection between terminal and coupling device

o Coupling device or line matching unit or line tuning unit for separating terminal equipment and power line

o Coupling capacitor for coupling signals into the transmission line

o Line trap for blocking the carrier signal back to substation

3.2. Teleprotection equipment for intertripping to the remote shall be capable of simultaneously transmitting and receiving signals between the line protective relays provided at each substation. The line protective relays shall be divided into two types. One can be used for the direct and permissive transfer trip scheme. The other can be used for the blocking and unblocking scheme.

3.3. Multiplexer shall consist of:

o 4 Wire E & M voice frequency modules

o 2 Wire voice frequency modules for PABX

o 2 Wire FXS, hotline

o V.35 synchronous data module

o RS232 asynchronous data module

o 64 Kbps ITU-T Rec. G.703 for teleprotection equipment

3.4. Private automatic branch exchange (PABX) for voice communication

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3.5. Optical line terminal equipment (OLTE) shall be designed to handle time sensitive applications such as protective relaying and shall be designed for back-to-back and drop-and-insert equipment.

3.6. Optical distribution frame (ODF) shall be suitable and large enough to accommodate the connection of all optical fiber and fiber cord leading to OLTE.

4) The communication block diagram for this project is provided in Annex 4.4.

9.2.11 Underground Cables

As mentioned in the revised Inception Report, the ADB’s Consultant noticed during a site visit at Pleiku S/S, that the 500 kV circuits coming from Hatxan S/S would cross three other 500 kV lines, including the lines coming from Yali hydro power plant and four 220 kV lines. The risks of such a situation are explained in Chapter 11, and this is the reason why the use of underground cables along the last 500 meters is strongly recommended by ADBs’ Consultant. The following map describes the vicinity of the Pleiku substation:

Fig 11

In order to be compatible with overhead transmission line, the minimum needed size of 500kV underground cable would be 2500 mm2 along the last 500 meters, laid in trough.

At this voltage level the terminations cannot be installed on the dead towers, but have to be constructed close to last towers in a restricted area of 25 x 25 m per circuit. The pictures below show a dead end tower with descents connecting underground cables to the cables terminations inside a substation. If EVN/NPT agrees on this principle, the ADB’s Consultant will study it in the final report, and will specify the underground cables.

The protection system shall take into account that if a failure occurs on the underground cable, there is no auto-reclosure on the feeder.

The Specification for 500kV Underground Cables is provided in Annex 5.5.

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Fig 12: Underground Cables Termination in 500kV Substation

Fig 13: Underground Cables Termination at Dead End Tower

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9.2.12 Bays permutation

According to the third tripartite meeting, EVN/NPT requested the consultant to check another solution to avoid the 500kV crossing, in permuting two existing bay (Phu Lam and Ialy), and install at the same place the future Ban-Sok (Hatxan).:

1. Analysis the advantages and disadvantages of the permutation of two bays:

* Technical solution:

- Adjustment the route segments of 500kV before connecting with the Pleiku 500kV substation:

- Constructing one tension tower with two circuits of the Hatxan-Pleiku 500kV transmission line at the appropriated position before connecting with the existing circuit ending towers of the circuit 500kV going to Ialy HPP and one circuit going to Phu Lam (dismantling the 3 bodies of tension towers of the left circuit going to Ialy HPP).

- Constructing a new adjustment route segment to connect the two circuits of 500kV going to Ialy HPP with the Pleiku 500kV substation, at the proposed extension area.

* Analysis of advantages and disadvantages:

- Disadvantages:

(1) It has to conduct a detailed survey to assess the ground situation, geographical, terrain around the Pleiku 500kV substation before design connection.

(2) It has to establish the adjustment alternative and get approval for the new the route direction arrangement with the local Authority.

(3) Electric shutdown duration to install the tension tower (for the adjustment route segments) under the 500kV transmission line going to Ialy HPP and going to Phu Lam is relatively long (7 days/ phase, with 3phases), it will cause a huge effect to the generating ability of the plant and the power supply to the Southern part of Vietnam.

- Advantages:

- The routes of 500kV transmission line are not crossed each other, therefore it does not affect each other case of conductor or earth failure.

2. Analysis the advantages and disadvantages on technical point of view

* Technical solution:

- The working items of the bays moving/going to Phu Lam (circuit 1) are as follows:

Dismantling, installing thecapacitorsand the switchgear equipments.

Dismantling, installing the reactor and the switchgear equipments.

Renovating the protection cabinet of existing bay going to Phu Lam to be proposed for bay going to Hatxan.

Installing the new equipment at the protection cabinet going to Phu Lam.

Total circuit testing for the bay going to Hatxan.

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- The working items of the bays moving/going to Ialy (circuit 1) are as follows:

Renovating the protection cabinet of existing bay going to Ialy in a bay going to Hatxan.

Installing new equipment at the protection cabinet going to the future bay to Ialy

Total circuit testing for the bay going to Hatxan

* Analysis the advantages and disadvantages of permutation works of bay going to Phu lam (circuit 1):

- Disadvantages:

The technical solution is complicated.

The existing devices in the substation shall be moved.

Electric shutdowndurationto conduct connection quitelong (about 20 days).

The generation unit of the Ialy HPP - 360MW shall be outage during about 20 days.

- Advantages: none

3. Cost Estimate of the permutation solution.

About 10,800,000 USD (construction costs: 2,000,000 USD; and electric shutdown operation costs: 8,800,000 USD)

4. Conclusion

Considering that the overcost is higher than the underground cables solution, and due to the constraints on the network operation, this solution has to be abandoned.

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9.2.13 Pleiku S/S Single line Diagram

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9.2.14 Pleiku S/S Layout

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9.2.15 Pleiku S/S in Case of Temporary Interconnection in 230/220 kV

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10 COST ESTIMATE FOR SUBSTATIONS

10.1 COST ESTIMATE FOR HATXAN SUBSTATION

The options 2 and 3 were added for financial simulation only. The option is the full scheme, and its corresponding cost has to be taken into account by the Lenders.

The costs are detailed in the tables below:

10.1.1 Option 1: Double BB Configuration with 3 AT 600MVA Full Scheme

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10.1.2 Option 2: Double BB Configuration with 3 AT 600MVA in case Xekaman 2 & 2A not connected

This option 2 was proposed, as to date the MOUs for Xekhaman 2 & 2A between VLPC and Lao PDR are no longer valid.

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10.1.3 Option 3: Double BB Configuration with 2 AT 600MVA in case XEKAMAN 2 & 2A and 4 & 4A not connected

This option 3 was proposed, in addition to option 2, in case Xekhaman 4 & 4A would be connected to Xekhaman 3 or directly to Vietnam, as both IPPs are close to the Vietnam Border (see Fig 17).

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10.1.4 Cost of Hatxan 230/115kV

10.1.5 Cost Estimate for O&M of Hatxan Substation

The yearly cost of O&M for Hatxan Substation is 1.2% of the construction cost.

10.2 COST ESTIMATE FOR EXTENSION OF PLEIKU SUBSTATION

10.2.1 Option 1: Overhead Line Connection

With 1.5 CB Configuration, including 2 shunt reactors 55 MVAr, with disconnectors, is 13.3 Million US$

10.2.2 Option 2: Underground Cable Connection

With 1.5 CB Configuration, including 2 shunt reactors 55 MVAr, with disconnectors, is 13.3 Million US$, and, +2 feeders underground cables 500kV 2,000 mm2 Cu along 500 meters, including terminations: 10 million US$ Total: 23.3 million US$

10.2.3 Option 3: with bays permutation at Pleiku S/S

According to 9.2.12 the bays permutation would impact an overcost of 10,8 millions US$,

Total: 24.1 million US$

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10.2.4 Temporary Configuration with Hatxan to Pleiku in 230/220kV – Additional Cost at Both Substations

This value was taken into account in the financial simulation, as these works are compulsory for the temporary step. In the financial simulation the temporary works in Pleiku were considered as taken in charge by the TPO.

10.3 COMMENTS ON THE COSTS

The unit costs in Vietnam are based on existing contracts, and are higher than the unit costs in Lao PDR. This can be partially explained because NPT specify 40kA during 3 seconds, instead of 1 second. In Lao PDR the Short Circuit reference for equipment is 50kA 1 s, however most of manufacturers are now providing equipment 40 or 50 kA at roughly the same price; the cost impact could be on the bus bars and steel structure. In the revised specifications for Vietnam, the closing resistors 600 ohms are cancelled as they are not needed, therefore the costs are reduced by 100,000 US$. Another fact may explain the cost difference, which is the packaging. In Vietnam the EPC contracting principle is not used, and the multiplication of contracts (at least x10) undeniably involves a cost increase, with added complications for management and supervision. All the above cost in Lao PDR, plus the temporary installation in Pleiku S/S for the temporary step 230/220kV are used for the financial simulation in this report.

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11 SYSTEM STUDY

11.1 INITIAL CONNECTION

11.1.1 On Vietnamese side

On the Vietnamese side the initial scheme was the connection to the existing Pleiku S/S. The distance of the line from Pleiku to the border is 93.5 km.

The 220 kV and the 500 kV substations are almost saturated, and with the connection of the two circuits from Hatxan, it will be saturated. The overhead line connection of the two circuits should over cross several overhead lines (at least three 500 kV circuits and four 220 kV circuits). In case of fault on the 500 kV circuits from Hatxan, the over crossed lines may also be affected, of which two circuits are coming from Yaly 720 MW hydro power plant, and then jeopardize the system. The probability is very high that the Vietnamese system will be split into two parts and in that case the generation/demand unbalance may drive to a blackout. It is therefore strongly recommended to connect the circuits from Hatxan via underground cables in order to mitigate the risks.

11.1.2 On Lao side

During the tripartite meeting held on September 6th in Vientiane, EDL proposed to design Hatxan 500 kV substation with the future interconnections with Thailand, Cambodia in addition with the interconnection with Vietnam and the 500 kV Laotian backbone. In that case Hatxan substation would be connected with four systems. In case of disturbances, all systems will be affected; in particular during the maintenance the whole exchanges between the four systems may be jeopardized. In addition, in case of disturbances, disputes will occur because the origin of the disturbance will affect other exchanges and there are no contractual agreements for compensations between the partners, except bilateral agreements, which are not relevant in such cases. A multilateral agreement may exist in the framework of a regional structure as it exists in Europe, but such structure is not yet planned to be implemented. In accordance with the latest version of the PDP, the connection is located at Hatxan 500 kV, which is now only connected to the hydropower plants with 230 kV lines. A temporary connection at 230 kV may be used, with only Xekaman 1 and Xekaman Xanxay in operation (year 2015).

11.2 REVIEW OF PDP IN VIETNAM

The Master plan 7, which covers the period until 2025, is approved by the Prime Minister on July 21st. In this Master plan, the load, which is a key figure for the system development is forecasted at 30974 MW and respectively 52617 MW and 77333 MW for 2020 and 2025. These figures determine the need of additional generation and the associated network reinforcement

Hatxan 230kV Hatxan 500kV Pleiku

500kV

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for the studied period. The demand growth rates used for the Master Plan are very high and imply large generation installed capacity reinforcement, taking into account that in 2010 and 2011 the installed generation capacity was not sufficient to cover the demand and load shedding was used periodically

Therefore, Vietnam implements a huge program of generation extension, which encompasses hydro power plants, coal or gas fired power plants and even nuclear power plants. In addition to these extensions of the national installed capacity, interconnection’s development program is under progress. The interconnection line Ban Sok (Hatxan) Pleiku 500 kV is included in this program.

The Institute of Energy is in charge of the network studies in Vietnam and in particular it carried out the studies for the Master plan 7. It is also in charge of the network studies for the Ban Sok-Pleiku interconnection project.



Fig 14: PDP VIETNAM IN PLEIKU AREA



11.3 REVIEW OF PDP IN LAO PDR

In Lao PDR, several versions of the PDP have been produced in a very short period of time, with large changes in the future network development. In particular in the previous version of the PDP, two backbones were planned: one 500 kV and another one at 230 kV for connecting all Laotian networks from North to South. The last version of the PDP, dated July, 8th, 2011, has been reviewed. In this version, there is no more 500 kV backbone for the Laotian system and only a 230 kV backbone is planned to be implemented, which is not compatible with the distance from North to South of the country. The Hatxan substation is no longer connected to the 500 kV system, but during the tri partite meeting held in Vientiane on September 6th, EDL required the modification of the substation design for the future interconnection with Thailand and Cambodia and the 500 kV Laotian backbone, this is a large discrepancy. In addition, a new 500 kV substation is implemented: Ban Sok, which is connected to Ban Lak and then Thailand and not connected to Hatxan. The hydro power plant Xepian Xenamnoy is connected to Ban Sok and Nam Kong 1 hydro power plant is connected to Saphaodong at 115 kV level and Xekaman Xanxay is also connected to Saphaodong at 115 kV level, instead of Hatxan through the double circuits line 230 kV from Xekaman 1. The hydro power plants Xekaman 4A and 4B are not more connected to Hatxan or to another substation. These changes may reduce the export to Vietnam and change the wheeling charges calculations. Finally, there is no more 115 kV level at Hatxan substation, this compromises the sharing out of the hydro generation, 20% dedicated to the Lao system, which could not be delivered from Hatxan. This may suppose that the delivery of the 20% of the hydro generation is done from other substations, maybe from directly from the hydro power plant. In that case the design of Hatxan substation may be modified, in particular the size of the 230/500 kV transformers. Nevertheless, due to the too many changes in Lao PDP and the lack of consistent information, the assumptions used for the network studies have been kept with the whole planned hydro power plants connected to Hatxan and 20% of the generation delivered to the Lao system, because the issues are worse for load flows, voltage drops and stability in case of high energy transfer. Therefore a lower energy transfer will reduce the constraints.



Fig 15: PDP LAO PDR Version March 2011



It should be noted that for this report, the design of Hatxan S/S, the System Study are based on the map dated 29 July 2010, as below:

Fig 16: PDP LAO PDR Version July 2010

In the last version of the PDP, the demand forecast takes into account the development of mining. The table hereafter presents the projects for mining development in the south. In accordance with this table, in 2019 the yearly industrial consumption in the south will be around 10 700 GWh for a peak demand around 1500 MW. The values for the year 2010 are respectively 360 GWh and 60 MW. The total demand forecast for 2019 is around 12 000 GWh for the south, taking into account the development of the residential consumption. The table hereafter presents these values, provided by EDL:


BAN SOK – PLEIKU DRAFT FINAL REPORT10-02-2012 Page 121 of 208



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CONSULTANCY SERVICES FOR PREPARING THE BAN-SOK PLEIKU POWER TRANSMISSION PROJECT 500kV OHL_TA 6481-REG


We may notice that the aluminium factory (SLACO) will consume 6 700 GWh for a demand equal to 900 MW from 2015. This project will be implemented in Attapeu region, where the hydro projects for exporting energy to Vietnam are implemented. The table hereafter presents the hydro project, which will be connected to Hatxan substation, the expected commissioning periods have been given during the tri partite meeting held in Vientiane in September 6th. Name Expected

commissioning year

Installed Capacity in

MW

Yearly average energy sold to Vietnam in GWh (80% of yearly output)

Yearly average energy sold to Laos

in GWh (20% of yearly output)

Xekaman 1

Xan Xay

2015 322 928 232

Xekaman 4 2016 80 253 63

Xekaman 4A 2016 116 363 91

Dak Emeule 2016 112 408 102

Xekong 3 up

Xekong 3 down

2016 105

100

640 160

Xekaman 2

Xekaman 2A

2017 100

64

511 128

Total 999 3103 776 At the end of the implementation of the hydro projects, the total installed capacity will equal to 999 MW and the yearly average energy generated will be equal to 3879 GWh and 80% of this amount should be exported to Vietnam, 3103 GWh. This amount should be compared with the forecast for 2015 equal to 10 000 GWh and the actual value for 2010, which is 880 GWh. Taking into account the export to Vietnam and the demand forecast, the energy generated for the year 2015 should reach roughly 13 000 GWh, without taking into account exports to Cambodia and Thailand. The industrial project SLACO has a load factor of 85% and requests 900 MW, but in low hydro season (around 6 months) the generation is around 20% of the installed capacity, which gives 200 MW in December 2017 and only 65 MW in 2015. Obviously these calculations are rough and only take into account the power projects in the south, however in the case that the energy would come from power plants implemented in the north (other hydropower projects, or thermal power plants), the planned 230 kV backbone will not enable the sufficient North-South energy transfer. It seems that the demand forecast, including the industrial project, the generation expansion plan and transmission Master plan, are not coherent with the energy export to Vietnam. All these topics are developed in the latest PDP. During the last tri partite meeting in Vientiane the Laotian Ministry of Energy, announced that thermal generating units will be implemented for covering the southern industrial demand. Such thermal units require large permanent cold water resources, which are not obvious.

11.4 THE GREAT MEKONG SUBREGION MASTER PLAN

The Master plan of the Mekong sub-region has been studied by TEPCO in 2007. This study proposed to interconnect the three systems: Laos, Thailand and Vietnam, through 500 kV lines in southern Laos: Pleiku, Ban Sok and Ubon 3. The hydro projects taken into account for this study are the following:

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Name of power plants Installed capacity MW Commissioning year

Xe Pian/Xe Namnoy 296 2013

Xe Kaman 1 488 2013

Xe Kong 4 464 2015

Xe Kong 5 388 2017

Nam Kong 1 229 2018 The installed capacity used in this study is equal to 1865 MW, larger than the value used for the hydro projects connected to Hatxan but less than the hydro projects in South Laos. The assumptions regarding the demand were the following:

Country unit 2004 2010 2015 2020

Laos MW 232.3 491 665 884

Laos GWh 1 102 2 721 3 623 4 757

Thailand MW 18 121 29 800 40 978 52 148

Thailand GWh 116 743 193 530 265 788 338 046

Vietnam MW 8368 19 550 32 196 48 642

Vietnam GWh 39 594 97 111 164 961 257 260 This Master plan was oriented for the interconnections development, and except for Lao PDR demand, the assumptions are not really different in the national PDP. For Vietnam, the peak demand for 2020 is forecast at 52 617 MW. The industrial development was not estimated in this study at the level, planned in Lao PDP. The Mekong regional Master plan supported the necessity of a 500 kV interconnection between Laos and Vietnam (Ban Sok-Pleiku), for economic and technical reasons. In the case of export of electricity from Xekaman 1, Xekong 4 and Xekong 5 to Vietnam at 230 kV level, instability risks may occur.

11.5 CONCLUSIONS ON THE PDP OF BOTH COUNTRIES AND THE GREATER

MEKONG MASTER PLAN

11.5.1 Great Mekong Master Plan

The Greater Mekong Master plan is supposed to be the first study, which represents a step in the regional interconnection project development. It is also the only project, which develops a regional strategy for exchange and development, and the studies carried out, take into account the three systems, even with the lack of data and forecasts. The interconnection of the three systems is profitable for all and enables the development of the hydro projects in southern Laos with the electricity exported to Vietnam or Thailand. The huge change in the Lao demand forecast modifies the export possibilities and therefore the interest of the interconnection. The PDP in Vietnam considers the interconnection with Laos as a connection for the delivery of the energy generated by the hydro IPP located in South Laos and sold to EVN. For the Laotian PDP it is supposed that the assumptions are similar for the export of electricity to Vietnam.

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11.5.2 Laotian PDP

Many PDP versions have been delivered by EDL in a very short period of time, with large modifications in the assumptions and therefore in the results. In particular, the demand forecast has a huge growth rate, due to the implementation of large industrial projects in the South, which are high electricity consuming such as aluminium industry. It seems that the energy generated, even with all hydro projects, will not be able to cover the internal demand (industrial and residential) and the export requirements. The network development has also been modified and the last version presents a 230 kV backbone, which seems to be very weak, regarding the amount of energy generated by the hydropower plants and the distance between the power plants and the consumption centres or the delivery points for exports. Risks of instability may occur.

11.5.3 Vietnamese PDP

The Master plan 7 is validated. Vietnam faces a large increase in its electricity consumption and has a large plan for generation development in Vietnam (thermal and hydropower plants). In addition, Vietnamese companies develop hydro projects in Laos, which are at different progress levels. The actual electricity balance presents a shortage of generation and, in peak periods, load shedding is used. The system has two main development centres Hanoi in the north and Ho Chi Minh City in the south. These two centres are connected with long 500 kV lines. These lines are equipped with serial capacitors, for stability purposes, however with the demand increase these lines should be reinforced to enable energy flow through the system.

11.6 SUMMARY OF HYDRO PROJECTS

Southern Laos has large potential hydro resources and several are under development. The actual consumption in Laos is low and these projects are generally developed by foreign companies for export to Vietnam and Thailand. The energy produced by the hydropower plants is gathered at Hatxan substation, which is connected to the Vietnam system by two 500 kV lines. The transmission from the hydropower plants to Hatxan is done at 230 kV or 115 kV levels. At Hatxan 80% of the power generated is exported to Vietnam and the remaining 20% is dedicated to local consumption fed by the 230/115 kV transformers in Hatxan. Ten hydropower plants are planned to be connected to Hatxan between 2015 and 2017, with a total installed capacity of 999 MW. The sites of Xekaman 1, installed capacity 290 MW, and Xan Xay, 32 MW, are under process and the dam is under construction. Xekaman 1 power plant is 20 km from the new location of Hatxan substation and it is planned to start operation at the end of 2015.

11.7 CURRENT STUDIES FOR CONNECTING HATXAN S/S TO THE VIETNAMESE

SYSTEM

The network studies are carried out by the Institute of Energy, which is in charge of elaborating the Master plan for the Vietnamese system. The interconnected system will be studied for three years: 2015, 2020 and 2025, for peak and off-peak load and for two hydro generation seasons: high and low levels. The data used for the Vietnamese system are the same used for the Master plan 7. The terms of the Power Purchase Agreements of the hydro power plants, specify that 20% of the hydro generation are dedicated to Lao consumption. It is supposed that EDL is able to maintain the flow through the 230/115 kV transformers at Hatxan, at this level. Due to the lack of information regarding EDL equipment beyond Hatxan 115 kV, the 20% has been modelled as a load connected to Hatxan 115 kV. For the study, it is assumed that the low level period for hydro generation is the same as the off peak period for the consumption. The load for off peak is equal to 60% of the peak load and the

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power factor is taken equal to 0.96 in Vietnam and 0.90 for the load in Laos. The hydro generation during the low level period is taken equal to 18.8% (2015), 19.1 % (2020) and 12.8 % (2025) compared to the high hydro level. These values are in accordance with the Master plan 7. In Vietnam, several solutions have been proposed for the connection of the 500 kV line double circuits coming from Hatxan:

Pleiku, initial location, validated by the Minister in 2008. The substation may be saturated at the 220 kV level and reinforcements of the 500 kV network in this area, are under study.

Kontum, a new 500 kV substation closer to the border, north of Pleiku

Duc Co, a new 500 kV substation, south of Pleiku.

These two new locations are studied in the framework of the reinforcements of the 500 kV network in the Pleiku area. However the location validated by the minister is still Pleiku and only this location has been studied by the IoE, in accordance with the tripartite meeting held in Hanoi, January 25th, 2011. This location has been confirmed with the validation of the Master Plan 7. In case of change, the effects of the new location for the interconnection should be studied, in particular in the case of Duc Co, which increases the length of the interconnection line and therefore decreases the system stability. The 500 kV line Hatxan-Pleiku has been modelled for the study, with a length of 162 km. Due to the change of Hatxan location the actual length for the line is 152.5 km, this will not modify the conclusions of the network studies. Each 500 kV circuit between Hatxan and Pleiku generates reactive power, around 170 MVAr. The reactive power generated by the line is generally compensated totally or partially. The normal design is the partial compensation and the percentage for compensation depends on the load factor of the line. In our case, the line will be lightly loaded even after the implementation of all hydro projects. In that case, the high level of compensation is required. A level of 60% for the compensation gives 102 MVAr, which should be equally shared at both ends and gives 51 MVArs. The standard value for reactor closer to this calculation should be implemented. At both ends of each 500 kV circuit a 55 MVArs reactor has been modelled. In Vietnam the peak load for 2015 is forecasted at 30 803 MW, including losses, which amount to 525 MW and the off peak load is forecasted at 18 482 MW, including 165 MW of losses. For 2020 the peak load is forecasted at 52 422 MW, including 883 MW of losses; the off peak load is equal to 31 453 MW, with 483 MW of losses. For 2025, the peak load is equal to 77 130 MW, with 1358 MW of losses, and 46 278 MW for off peak including 837 MW of losses. The table below presents the hydro power plants taken into account in the network study:

No. Name of HPP Installed capacity (MW) Operation Year

1 Xekaman 1 290 2014

Xekaman Xanxay 32 2014

2 Xekaman 4 80 2014

Xekaman 4A 116 2015

3 Dak E Meule Up. 18 2015

Dak E Meule Mid. 112 2015

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No. Name of HPP Installed capacity (MW) Operation Year

4 Xekaman 2 100 2016

Xekaman 2A 64 2016

5 Xekong 3A Upstream 105 2015

Xekong 3B Downstream 100 2015

Total 1017

With this table, the exchanges by year and season may be calculated. These calculations are presented in the tables hereafter:

No. Name of HPP 2014 2015 2016 2017 2018 2019 2020 2025

1 Xekaman 1 290 290 290 290 290 290 290 290

Xekaman Xanxay 32 32 32 32 32 32 32 32

2 Xekaman 4 80 80 80 80 80 80 80 80

Xekaman 4A 116 116 116 116 116 116 116

3 Dak E Meule Up. 18 18 18 18 18 18 18

Dak E Meule Mid. 112 112 112 112 112 112 112

4 Xekaman 2 100 100 100 100 100 100

Xekaman 2A 64 64 64 64 64 64

5 Xekong 3A Upstream 105 105 105 105 105 105 105

Xekong 3B Downstream 100 100 100 100 100 100 100

A Total (MW) 402 853 1017 1017 1017 1017 1017 1017

B=0.2*A Provide to Lao's load (MW) 80 171 203 203 203 203 203 203

C = A-B Remaining Power to Vietnam (MW) 322 682 814 814 814 814 814 814

Export on the 500 kV line Hatxan Pleiku for high level hydro

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No. Name of HPP 2014 2015 2016 2017 2018 2019 2020 2025

1 Xekaman 1 54.5 54.5 54.5 54.5 54.5 54.5 55 37

Xekaman Xanxay 6 6 6 6 6 6 6 4

2 Xekaman 4 15 15 15 15 15 15 15 10

Xekaman 4A 22 22 22 22 22 22 15

3 Dak E Meule Up. 3 3 3 3 3 3 2

Dak E Meule Mid. 21 21 21 21 21 21 14

4 Xekaman 2 19 19 19 19 19 13

Xekaman 2A 12 12 12 12 12 8

5 Xekong 3A Upstream 20 20 20 20 20 20 13

Xekong 3B Downstream 19 19 19 19 19 19 13

A Total (MW) 75 160.5 191.5 191.5 191.5 191.5 192 129

B=0.2*A Provide to Lao's load (MW) 15 32 38 38 38 38 38 26

C = A-B Remaining Power to Vietnam (MW) 60 128.5 153.5 153.5 153.5 153.5 154 103

Export on the 500 kV line Hatxan Pleiku for low level hydro

It should be noted that the commissioning dates for the hydro power plants are earlier than the ones given during the tri partite meeting held in Vientiane. But, these studied cases are worse regarding the stability, because the percentage of these imports to the demand in Vietnam is greater and consequently the effects on the stability larger. The following single line diagrams present the network modelled for the studies:

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Network modelled for the year 2015

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FIG N° 17 - 230kV and 500kV TRANSMISSION LINES

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11.7.1 Static Results

Normal Conditions The initial connection is Pleiku 500 kV. The interconnected system has been modelled for the three selected years 2015, 2020 and 2025 and for the two load levels. The single line diagrams, in annexes 25-1 to 25-6, present the load flows and the voltage profiles in normal conditions (all equipments in operation). In 2015, for peak load (which means an import of 682 MW from Hatxan), two 500 kV lines around Pleiku are over-loaded (Pleiku-Dak Nong and Dak Nong-Cau Bong) and the other 500 kV lines are heavily loaded. In Vietnam the 500 kV lines are very long and most of them are equipped with serial capacitors for stability improvement. The limitation, for the two 500 kV lines over-loaded, is due to the serial capacitors and it is supposed that the up-grading of the serial capacitors is planned before 2015. This assumption is acceptable, because even without the interconnection with Hatxan, these two 500 kV lines do not comply with the N-1 rule. Regarding the voltage profile some 220 kV substations in Ho Chi Minh area are outside of the voltage limits, but this is not the case in relation to the Hatxan interconnection. Single Contingency The tripping of one circuit of the interconnection and the tripping of the most loaded circuit in Vietnam have been studied, for peak and off peak and for 2015, 2020 and 2025. In case of tripping of one interconnection circuit, no over load occurs and the voltage is kept within the limits for all the studied cases. The tables of the results are presented in annexes 25.7 to 25.9. In 2015, the remaining interconnection circuit is loaded at 39% of its capacity, for peak load and 7.5% for off peak; for 2020, the remaining interconnection circuit is loaded respectively at 47% and 11% and it is the same in 2025, because the import is similar. The most loaded circuits in Vietnam are: Dak Nong-Cau Bong, Pleiku-Di Linh and Di Linh- Tan Dinh. In case of tripping of Dak Nong-Cau Bong, Pleiku-Di Linh and Di Linh- Tan Dinh are over loaded and in case of tripping of Pleiku-Di Linh or Di Linh- Tan Dinh, Dak Nong-Cau Bong is over loaded. The over load is due to the limitation of the serial capacitor, which should be up-graded to 2000 A and this should be done before 2015. After that no other over load is detected in case of single contingency. Short Circuit level The short circuit currents, 3-phases and single phase at Hatxan and Pleiku have been calculated. Only the peak cases have been studied, because they present the larger short circuit current. The table hereafter presents the results for the studied years:

Year/Substation Hatxan 500 kV Hatxan 230 kV Pleiku 500 kV Pleiku 220 kV

2015: 3-phases current 10.8 kA 15.4 kA 28.9 kA 27.9 kA

2015: 1-phase current 8.7 kA 14.6 kA 26 kA 28 kA

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2020: 1-phase current 9.4 kA 15.6 kA 28.3 kA 28.8 kA


2025: 1-phase current 9.8 kA 15.6 kA 31.9 kA 33.1 kA

In 2025, the level of the 3-phases short circuit current in Pleiku overshoot the limit (40 kA), therefore at that time measures should be taken in order to reduce the level of short circuit current. The short circuit current level is a big issue, difficult to solve and this should be taken into account in the development plans. Pleiku substation is a key point of the Vietnamese system and the reinforcement of the system, in particular the connection of new generating units increase the short circuit current in Pleiku. The counter measures should be planned in advance, in order to keep the current below the technical limits, because such problem is not solve by the implementation of new transmission elements, but by the planning methods and the operational rules.

11.7.2 Dynamic Results

The dynamic simulations deal with frequency and voltage variations in cases of tripping, the tripping of the most loaded circuit in Vietnam: Dak Nong- Cau Bong has been studied and the case of a short circuit on the busbar at Hatxan and Pleiku 500 kV. In addition, the maximum clearing time has been evaluated at Hatxan 500 kV and 230 kV and at Pleiku 500 kV and 220 kV. This parameter gives a good view of the stability of the system in case of contingencies. These calculations have been carried out for the studied years and for peak and off peak periods. For all studied cases, the system remain stable, in case of short circuit at Pleiku the system is more affected but return to the initial values after around 30 s, which is acceptable and the effects of a disturbance are greater for off peak period, which is normal because less generating units are connected to the system and consequently the system has a lesser short circuit power, which is an indicator of its stability. It is assumed that all faults are cleared within 80 ms, which is the operational time of the protection devices. The trends are presented in annexes 5.10 (sheets 25.10 to 25.18) The table hereafter presents the maximum clearing time at Hatxan 500 kV and 230 kV and at Pleiku 500 kV and 220 kV: Years/substations Hatxan 500 kV Hatxan 230 kV Pleiku 500 kV Pleiku 220 kV

2015 228 ms 212 ms 260 ms 228 ms

2020 202 ms 166 ms 244 ms 244 ms

2025 178 ms 150 ms 222 ms 118 ms

The maximum clearing time is greater than the operational time of the protection devices, but it decreases along the studied period and at the end the margin is limited. Therefore, the protection devices should be carefully designed in order to insure a clearing time of 80 ms for all cases.

LAO PDR / VIETNAM




11.7.3 Temporary Connection

The last planning of the company in charge of the construction of Xekaman 1 schedules synchronization to the network for the end of 2015. The time needed for the study and the building of the 500 kV line and the substation is at least 4 years. That means that the transmission facilities implementation could be critical with regards to the COD of the first hydro power plant. This is a reason why a backup transmission solution should be investigated in case of delay due to late decision. For that purpose it is proposed to study the connection at 220 kV level, using the 500 kV lines. In Lao PDR the nominal voltage is 230 kV. In Vietnam the nominal voltage is 220 kV. Although the voltage level is different the substations can be interconnected, because the operational voltage values should be within +/- 10 % around the nominal value. Thus the operational voltage for the interconnection should be agreed between EVN and EDL and included in a common Agreement /PPA. It is reminded that a higher operational voltage level improves the stability and reduces the transmission losses. The scheme below presents the temporary connection:

This solution is also investigated in order to optimize the schedule of investment cost to allow the TPO Company to reduce the costs at the beginning of its activity, when the revenue (2015) will be low due to the connection of Xekaman 1 and Xanxay. For example the installation of the 230/500 kV auto transformers could be postponed. At 220 kV level the flow should be limited for stability reasons in case of 3-phases short circuit on the interconnection line. Thus, only Xekaman 1 and Xanxay will be connected to Pleiku 220 kV. The single line diagrams in annexes 5.10 (25-19 to 25-20), present the load flows and the voltage profiles in normal conditions (all equipments in operation). It should be noted that even with only Xekaman 1 and Xanxay, which means an exchange of 256 MW at 220 kV the 500 kV lines, Pleiku-Dak Nong and Dak Nong-Cau Bong are over-loaded and Pleiku-Di Linh is heavily loaded. Therefore, the same reinforcements of the Vietnamese system, are required, as the case of 500 kV operations. In case of single contingency, with the reinforcements of the same lines 500 kV: Pleiku-Dak Nong, Dak Nong-Cau Bong and Pleiku-Di Linh, no over load occurs, in case of tripping of one interconnection circuit. The results are presented in annex 5.10 (25.21). The short circuit currents 3-phases and single phase have been determined at Hatxan and Pleiku in case of temporary connection and the table hereafter presents the values:

Hatxan 230 kV Pleiku 220 kV

Xekaman 1

Pleiku

220kV

Hatxan

230kV

500kV Lines

Used 220kV

LAO PDR / VIETNAM




3-phases Short circuit current 7.3 kA 29.5 kA

1 phase short circuit current 6.4 kA 29.3 kA

The dynamic simulations have been carried out in case of temporary connection, the system remains stable and returns to its initial values after around 25s, which is acceptable. The trends are presented in annexes 5.10 (25.22 and 25.23 The maximum clearing time, in case of 220 kV operation is equal to 204 ms at Hatxan 230 kV and 214 ms at Pleiku 220 kV, these values give a sufficient margin for operations. All these calculations have been carried out, taking into account only the connections of Xekaman 1 and Xekaman Xanxay, with the connection of other hydro generating units, the operations at 220 kV are not recommended, because of the risk on the stability due to the increase of the flow on the interconnection line.

11.8 CONCLUSIONS

The 500 kV network in Vietnam is heavily loaded and should be reinforced soon. For the studied period it is supposed that the peak load will grow from 30 000 MW to 77 000 MW and obviously the installed capacity should increase at almost the same rate, even taking into account the interconnection. Therefore, due to the time requested for the implementation of new transmission elements, the decision should be taken rapidly. The assumptions adopted for the Laotian system are poor, but the information from EDL is not sufficient for modelling the 115 kV network, which will be fed by Hatxan. In addition, the contractual rule for the energy splitting (80/20%) does not seem to be applicable, with the relations between the involved entities: EDL, EVN and the hydro company. Moreover the demand forecast in Laos, is not coherent with the generation development plan and the planned exchanges. For the studied cases the interconnected system remains stable, but before 2025 the short circuit current in Pleiku will over shoot the technical limits and this should be taken into account in the development of 500 kV network in Vietnam. Pleiku is a key substation in Vietnamese system, but is saturated and close to the technical limits for short circuit current. The 500 kV network in central Vietnam, Pleiku area, should be adapted to face the demand increase and the connection of the new generating units, in compliance with the technical limits. In Laos, it seems that the development of an interconnected national 500 kV network will be necessary, due to the demand growth, the north-south distance and the interconnection projects in progress. At that time, a network study should be carried out with new assumptions, taking into account the whole Laotian system and the interconnected neighbouring ones. The two systems will be interconnected with the commissioning of the 500 kV line Hatxan-Pleiku and in the future, in accordance with the Greater Mekong region plan, Laos and Vietnam will be interconnected with Thailand. Systems interconnected should respect common rules and in particular to avoid black out or the spreading of large disturbances over the interconnected system. For that purpose the defence plan of each system should be harmonized in order to be compatible. The first step of this harmonization is the implementation of a common automatic under-frequency load shedding scheme, which will avoid the total collapse of the interconnected system.

LAO PDR / VIETNAM




For the time being there is no automatic underfrequency load shedding in Vietnam; if needed, the dispatch centre manages it manually. In Laos the case is similar. The interconnection of systems reinforces each system, but the operational rules must be defined and mutually agreed in order to operate the system smoothly and for the common benefits. The common under frequency load shedding scheme is necessary for interconnected operations and with the future interconnection with Thailand, this will be crucial. The sharing of reserve is also a possibility in an interconnected system as well as the common control of the voltage level and the reactive flows.

LAO PDR / VIETNAM




LIST OF ANNEXES

VOLUME 3 LAO PDR STUDIES

ANNEX 3.1 – TL & S/S IEE IN LAO PDR

ANNEX 3.2 – TL & S/S LARAP AND RESETTLEMENT POLICY FRAMEWORK IN LAO PDR

VOLUME 6 VIETNAM STUDIES

ANNEX 6.1 – TL & S/S IEE IN VIETNAM

ANNEX 6.2 – TL & S/S LARAP IN VIETNAM

VOLUME 7 DUE DILIGENCE REPORT

ANNEX 7.1 – SUMMARY OF STATUS OF ASSOCIATED PROJECT END OF 2011

ANNEX 7.2 – ENVIRONMENTAL DUE DILIGENCE ON THE ASSOCIATED

ANNEX 7.3 – SOCIAL DUE DILIGENCE ON THE ASSOCIATED PROJECTS

ANNEX 7.4 –FINANCIAL AND ECONOMIC CALCULATION TABLES

Date post:	24-Jul-2020
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