LAGUNA VERDE NPP Unit 1&2 - International Atomic … · • The CNSNS took the initiative of...

Gerencia de Centrales Nucleoeléctricas

“ Plant Life Management for Safe Long Term Operation (PLiM)”

LONG TERM OPERATION CNLV (LTO)

LAGUNA VERDE NPP Unit 1&2

February 2017


Laguna Verde Nuclear Power Station is a dual unit facility that is located on the coast of the Gulf of Mexico in the state of Veracruz, Mexico. The nuclear reactor system for each plant unit includes a single-cycle, forced circulation, General Electric boiling water reactor (GE BWR Type 5), housed within GE Mark II containment.

Reactors type: BWR Thermal power: 2,027 MW (th) Electric power output per unit: 810 MW(e)


• Focus to LV LTO:

– To implement the processes to operate LVNPP units 1&2 with safe and reliability during the remaining licensed period and the extended period.

– To integrate evaluation and monitoring activities for SSC like maintenance rule,

reliability program, in service inspection plans, surveillance programs, obsolescence and aging management programs.

– Optimization of maintenance, reliability and life service of SSC.

– Integration of aging management programs with economic plans for optimizing resources.

– To get from CNSNS (Mexican Regulatory Body) the operating permission to operate

for an extended period of 30 years additional to the original currently license. 2050 for U1 2055 for U2.


Plant life management for Long Term Operation


Plant life management for Laguna Verde NPP Long Term Operation


• Models identified:

– European.- LTO and aging management implementation in accordance to requirements contained in guides and rules established by IAEA.

– American LTO.- reliability process implemented

through INPO AP 913 document & MR (active components) and aging management implemented according to US license renewal rule 10CFR54 (passive components), for granting operating beyond the 40 years.


• LV NPP follows the NSSS origin country regulation (USA). The methodology approved in that country for License Renewal is the rule for the LV NPP License Renewal process:

– 10CFR54 "Requirements for Renewal of Operating Licenses for Nuclear

Power Plants“

– 10CFR51 "Environmental Protection Regulations for Domestic Licensing and Related Regulatory Functions"; 10CFR5I Subpart A "Format for Presentation of Material in Environmental Impact Statements"


• For LV NPP Unit 1&2, both licenses were granted for 30 years, although all design criteria and analysis were performed for 40 years, for that condition the LV License Renewal Application request an extended operation period for 30 year to the Mexican regulatory body CNSNS.

• The end of LV Unit 1 currently license will be in 2020, this mean less than 3 years for getting the new license, LVNPP is implementing all the commitments that were included in the LV LRA summited to CNSNS in 2015, 5 years before to the start the Extended Operation Period.

• The CNSNS took the initiative of organizing stress tests in the wake of the Fukushima accident. On October, 2012, the plant submitted to the CNSNS the report on the stress tests conducted in LV NPP.

Current Status

Reliability Program implemented according to AP 913 document in optimization process to enhancement the Maintenance Plans.

Proactive Obsolescence Program in way through POMs System.

Implementation documents prepared like new procedures and

modification of existent procedures needed to meet the aging management requirements according to US GALL.

In preparation the work orders and schedules needed for the

implementation of activities during next outages and normal operation period of both units.

In process the investment project for the inspection and

monitoring activities related with License Renewal (USD $50 M).



LV NPP License Renewal Plan 2015-2020


Scoping criteria apply

10CFR54.4(a) (1) Safety Related Systems, Structures, and

Components (SSCs)

(2) Non-safety related SSCs whose failure could impact a safety function

(3) SSCs credited for a regulated event • Fire Protection (50.48)

• Environmental Qualification (50.49)

• Pressurized Thermal Shock (50.61) – PWR only

• Anticipated Transient Without Scram (50.62)

• Station Blackout (50.63)


Screening process

Were identified each component type from the Flow Diagrams and Plant design documents.

Confirm the list of component types using the Equipment Lists in plant data bases for the systems.

It was prepared a master list of components by tag number, and environmental / material

This information was added to the LR database

41966 lines conform the main LR list with all the combinations of material and environments.


AMR process With the material and environments determined we proceeded with AMR work. The work started with AMR, but AMP reviews was performed in parallel. There has been some iteration as part of the AMR work for determining AMP consistency.

AMR reviews includes some knowledge of the scope of the AMPs credited

AMP evaluations includes knowledge of the scope of the

program


Aging management programs review

The review of the AMPs was based on the actual implemented procedures at Laguna Verde

Part of the process was to identify all the procedures which can be credited for complying the criteria of AMP´s US GALL.

“Procedures” is an inclusive term that includes: procedures, surveillances, preventive maintenance

activities, recurring work orders, chemistry sampling.


All Aging Management Programs credited for the LV LRA were reviewed against the 10 elements identified in US SRP NUREG-1800 R2 and US GALL NUREG-1801 R2.

For AMPs that are described in US GALL, Sections X and XI, exist

an description of the programs in detail that was take like model.

For AMPs that are not described in US GALL, there are generic attributes of the AMP described in US SRP that was take.

48 AMPs include AMPs with enhancements required and new

AMPs to implement in LV NPP as result as AMR process.


TLAA’s validation

The TLAAs are calculations and analysis that meet all of the following 6 conditions:

1. Involve SSCs in scope of license renewal 2. Consider the effects of aging 3. Involve time-limited assumptions based on the

current operating term 4. Relevant in making a safety determination 5. Conclusions or basis for conclusions that the SSC is

capable of performing its intended function 6. Contained of incorporated by reference in the CLB


Each TLAA must be evaluated to demonstrate that:

(i) The analyses remain valid for the period of extended operation;

(ii) The analyses have been projected to the end of the period of extended operation; or

(iii) The effects of aging will be adequately managed for the period of extended operation.


LV NPP TLAAs

Evaluations were done performed by contractor (SIA) and results were included in the LV LRA chapter 4.

The major problem for LV was the lack of design information overall for the vessel and Reactor internals, in order to solve it, GE, EBASCO(URS) support in this work.

2015 2016 2017 2018 2019 2020 2021

First updating of LRA submission to CNSNS.

Inspection, monitoring and additional activities needed for complying the AMP´s committed (activities scheduled for next cycles and outages)

LR appl. Submmi.to CNSNS

Third LRA updating submission CNSNS.

Fourth LRA updating submission CNSNS.

Fifth LRA updating submission CNSNS.


DOCUMENTAL IMPLEMENTATION IMPLEMENTATION OF PLANT INSPECTIONS, MONITORING AND ANALYSIS ACTIVITIES

Implementation procedures development.

Data base development for AMPs implementation control.

Development of additional analysis committed

Activities related with audits, inspections and RAI´s required for CNSNS

Second LRA updating submission CNSNS.



IAEA Pre-SALTO Mission & Follow up

The follow-up mission was organized in January 2017 to

review appropriateness and progress of solutions of the

pre-SALTO mission issues reported in 2015. LV NPP

provided advance information package, describing

counterpart actions to address recommendations and

suggestions made previously, one month before the

follow-up mission to the IAEA review team. Five days

follow-up mission included introductory presentation of

the plant, discussions and interviews of responsible

counterparts.


Issue No. / follow result

Fundamental Overall Problem Rec. Sugg.

Reviewed Area A: Organization and functions, current licensing basis (CLB), configuration/ modification management

A-1 / SPD Project strategy, tasks, responsibilities, organization and coordination concerning the implementation of LTO project are not appropriately defined.

1 -

A-2 / SPD Organizational arrangement for improvement of ageing management at the plant after LR evaluation is not adequate.

- 1

Reviewed Area B: Scoping and screening and plant programmes relevant to LTO

B-1 / IPD Scoping and screening process at the plant does not assure that all SSCs are in the scope for evaluation for LTO.

1 -

B-2 / SPD Existing plant programmes relevant for LTO are not adequately enhanced for LTO.

- 1

Reviewed Area C: Ageing management review, review of ageing management programmes and revalidation of time limited ageing analyses for mechanical components

C-1 / IPD The ageing management review is not properly supported by a condition assessment of all in-scope SCs.

1 -

C-2 / SPD The plant does not have documented approval of all documents prepared by contractors that support their LTO programme.

- 1

C-3 / SPD The proactive part of the obsolescence programme is not in place yet. - 1

C-4 / SPD Operating experience from the whole operational history of the plant was not considered for LTO.

1 -

LV NPP Pre-SALTO Mission results & Follow up


Issue No. . / follow result

Fundamental Overall Problem Rec. Sugg.

Reviewed Area D: Ageing management review, review of ageing management programmes and revalidation of time limited ageing analyses for electrical and I&C components

D-1 / IPD There is no temperature monitoring programme in place at the plant to identify hot spots, which can demonstrate that operational temperatures for the SCs in the EQ programme do not exceed the temperatures used in the calculations for qualified life.

1 -

Reviewed Area E: Ageing management review, review of ageing management programmes and revalidation of time limited ageing analyses for civil structures

E-1 / SPD Ageing management of containment suppression pool and associated components is not effective.

1 -

E-2 / IPD The AMR tables do not cover evaluation for all known ageing effects and do not designate the most stringent AMP for managing the ageing effects.

- 1

E-3 / SPD Visual inspections of containment liner plate, penetrations, and concrete before Integrated Leak Rate Tests (ILRT) and at periodic intervals in between the ILRT were not performed.

1 -

E-4 / SPD Many AMPs, which are identified by LR evaluation as important for managing ageing, are currently not implemented.

1 -

LV NPP Pre-SALTO Mission results

IMPLEMENTATION PROCEDURES






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