Preliminary Estimation of Waste Quantities for Economic and Safe Decommissioning
(The Case of Kori-1 NPP)
I
III
II
Contents
Joint Research
Process of Estimating Wastes Quantities
General Assumptions for K-1 Decommissioning
IV Empirical Results
V Conclusion
3
05.31.1972 ConstructionOperation Permit
06.19.1977 First Criticality
04.29.1978 Commercial Operation
06.18.2007 Design Lifetime Expiration
12.11.2007 Continued Operation Permit (6.19.’07 ~ 6.18.’17 : 10yrs)
01.09.2008 Continued Operation
06.18.2017 Permanent Shutdown
4
Requirements for Decommissioning process - Safety and impact analysis for adjacent NPPs - Common and shared systems and facilities - Groundwater contamination and site remediation - Spent fuel management and waste quantities estimation
• D&D and site restoration after an optimal cooling period
• Cold to hot
• Partial Hot to Cold (Prevention of contamination)
• D&D of contaminated SSCs after transferring SF
Decom Direction Cold to Hot
Decom Strategy A Vs. B
Project Structure Tier 1,2,3 C
A B
T
Site Restoration Brown Field
• Site restoration appropriate to restricted use
• Flexible restoration principle by regulation
changes depending on site release criteria
• A : DECON + Part of SAFSTOR ☞ K-1
• B : DECON ☞ Followed by the other plants
※ 2-unit D&D constructed under the same license
• Tier 1 : KHNP(EPC)
• Tier 2 : Major companies, R&D/Academic Insti.
• Tier 3 : S&M companies
Decommissioning principles
5
Site remediation for 2yrs
Dismantling & Decontamination for 6yrs
Spent Fuel cool-down for 5yrs
Pre-Decommissioning for 2yrs +
+
+
Decommissioning Schedule of Kori-1 NPP
Total = 15yrs
KAERI
GODO Tech
KINGS RADCORE
Univ. Chosun
KEPCO E&C
• Sampling and collecting methodology
• Evaluation of radiochemistry pretreatment, separation, nuclide inventory
• In-Situ measurement methodology of Major SSCs
• Source term evaluation of non-radioactive areas
• Waste Quantity evaluation • Waste management strategy
• Waste quantity evaluation of the Primary system and major SSCs
• PWR radio-activation evaluation model
• Source term evaluation around reactor core
3D waste quantity
evaluation
• PHWR radio-activation evaluation model
• Source term evaluation around reactor core
6
Activation Inventory
Calculation
Calculation Using CRUD
in systems
Radiation Survey
Analysis
Site Radiation Analysis
Quantity, m3
(DECON) Project
Management
RADCORE (MCNP
+FISPACT)
Univ.Chosun (CRUD
Calculation)
GODO Tech (ISOCS:In-situ Object Counting System)
KAERI (Represent Sampling &
Analysis)
KEPCO-ENC (Waste
Quantity Estimation)
KHNP-CRI (Total process ·3D Quantity Calculation)
Division of Responsibility
7
8
How to quantify the wastes of Kori-1?
- Estimate the radioactive waste quantities
- Establish practical waste management strategy
- Lead to successful decommissioning
Evaluation and Verification (Radioactive sources and wastes)
- Reactor Vessel, Reactor Vessel Internal components
- Control rod assembly
- Bio–shield concrete
- Corrosion and Contaminated materials in the primary system
- Radioactive waste treatment system and structures (soil, liquid, dry active wastes, hazard wastes etc..) - Others
13
Waste Treatment
Problem
1. Difficult to secure the site for the permanent disposal
2. Disposal cost of radioactive waste : Korea≫USA per unit volume
Striving for reducing the waste quantities
1. Performing the preliminary evaluation - To demonstrate the disposal cost with volume reduction economically than the direct disposal process
2. Considering the integrated waste treatment facility - Equipment for Separation, Cutting, Decontamination, Incineration, Melting, Compression etc.. - For contaminated soil portable decontamination equipment
Solution
14
Large Components Dismantlement(RV, SG, RCP, PZR)
Disposal Ways
1. One piece removal
2. Segmentation
Problem & Solution
Problem : Our disposal facility does not consider storage space for one piece removal
Solution : Selecting the segmentation and decontamination in the decommissioning site
- Requirements : Acceptance Criteria, Sizes of drums - Factors : Occupational dose, Costs, Schedule
Requirements & Factors
15
Packaging and Shipping
Korean Disposal facility
1. Cave type Silo for ILW & LLW (200L, 320L drum)
2. Near surface type* for LLW & VLLW
(To encompass drums in rectangular parallelepiped concrete vaults)
Transportation
Efficiently transfer wastes to the disposal facility - Using the intermodal metal box - Overland or marine transport
* Under construction; planned in Operation(’20)
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Input Output
Waste classification and type
Unit volume and density
Radiation source Area designation Plant inventory Waste treatment Planning Packing,
Transferring, Disposal
DeCAT-Pro
LLW ILW VLLW CW
Location Level Volume Generated
and Disposed Quantities
Evaluation Tool
Evaluation Process of Waste Quantity
17
Classification and Disposal Methods of Radioactive Waste
IAEA Korean Nuclear Safety Law
* IAEA Safety Standards No.GSG-1(’09) *18th Nuclear Safety And Security Commission(NSSC,’13)
Classification Standard Radioactive
Waste & Quantities High Level Waste
Half life & Heat release rate(SF)
- Half life : ↑20 yr - Nuclide : α - Concentration : 4,000 Bq/g - Heat release rate : 2 kW/m3
Intermediate Level Waste
LLW excess - LLW Classification Standard ↑ - Sealed Source waste - High Level Resin waste ※ Concentration range is broad, Small waste quantities
Low Level Waste
1 mSv/yr↓ (Disposal Worker)
- 10 nuclides & specific activity of total alpha decay standard*
Very Low Level Waste
1 mSv/yr↓ (No radiation protection)
- Exempt Waste Χ 100 ↓ - α-Nuclide Over 20 yr Half life
Exempt Wastes
10 μSv/yr↓ - IAEA RS-G 1.7 Standard Concentration or Dose↓
*10 nuclides : H-3, C-14, Co-60, Ni-59, Ni-63, Sr-90, Nb-94, Tc-99, I-129, Cs-137, Total α (3.7Χ103)
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Grade of Wastes Waste Type Volume (m3)
Clean Wastes
Cable
139,527
Pieces of concrete, Hazard waste
Asbestos Large component Small components
SF Rack
ILW Small metals
23 Resin and Filters
LLW
Cable
5,673
Pieces of concrete Scrabbling concrete Dry Active Wastes
Hazard wastes Asbestos
Large components RV
Small metals SF Rack
Resin and Filters
VLLW
Cable
6,829
Pieces of concrete Scrabbling concrete
Hazard wastes Asbestos
Small metals SF Rack
Resin and Filters
Total Radioactive Wastes 12,526
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Comparison of the Radioactive Wastes
Type of Radioactive Wastes
Radioactive Wastes Generated (m3)
Maine Yankee (Actual)
(900 MWe)
Conn. Yankee (Actual)
(582 MWe)
Kori-1 (Estimated) (587 MWe)
Large Component 2,077 6,858
1,031
Commodities (Metals) 7,551 10,215
Concrete 47,289 19,311 551
Soil 17,826 45,613 -
Distributables (Others) 999 1,092 729
TOTAL 75,743 72,874 12,526
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Comparison of the Radioactive Wastes between DECON and SAFSTOR
Radio
active
Waste
s(m
3)
Cle
an W
aste
s(m
3)
21
Current Status
1. With no full experience of commercial NPP decommissioning
2. Not enough technical readiness
3. Consideration of multi-site impact
4. In need of more waste disposal facilities, etc.
5. Development of methodologies and data to be a good starting point
1. Still in need of tenacious efforts for the successful decommissioning
2. Keeping an eye on trends of regulation and government policy
3. Positive attitude to acquire the precedent decommissioning know-hows
4. Numerous others...
Assignments