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

9

10

Radiological Characterization

11

Decommissioning Zoning

12

Decommissioning Zoning of Containment and Aux. Bldg

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

19

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

Thank you