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Central Research Institute of Electric Power Industry

Spent Fuel Management in Japan

2015

INMM Spent Fuel Seminar, Washington DC, USA

Jan. 13, 2015

Masumi WATARU

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Contents1.Regulatory and Operational Status2. Japanese studies on the Spent Fuel Storage3. Summary

2015 2

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1. Regulatory and Operational Status after Fukushima Accident

Mar. 11, 2011 Tohoku Big Earthquake Sep. 19, 2012 Establishment of Nuclear Regulation Authority Apr. 12, 2013 Start of Cask Transfer from Dry Storage Facility to Common Pool at Fukushima

Daiichi NPP (Completion on May 21, 2013) July 8, 2013 Enforcement of New Regulatory Requirement for Nuclear Power Plant

First Applications to restart 10 Reactors Aug. 22, 2013 Completion of Construction of the Dry Storage Building at Mutsu Site of RFS

(Start on Aug. 31, 2010) Nov.18, 2013 Start of Fuel Removal from Unit 4 Spent Fuel Pool at Fukushima Daiichi NPP

(Completion on Dec. 22, 2014) Dec. 18, 2013 Enforcement of New Regulatory Requirement for Fuel Cycle Facilities and

Research Reactors Jan. 15, 2014 Application of RFS Dry Storage Facility Mar. 1 , 2014 Integration of the JNES into the NRA Apr. 11, 2014 Cabinet Approval of New Basic Energy Plan Sep. 10, 2014 Permission for Change in Reactor Installation of Units 1 and 2, Sendai NPP, Kyusyu

Electric Power Co.

2015 3

Integration of JNES with NRA

2015 4

Nuclear Regulation Authority

The Secretariat of the Nuclear Regulation Authority

Incorporated Administrative Agencies

Japan Atomic EnergyAgency

National Institute ofRadiological Sciences

Japan Nuclear EnergySafety Organization

Integration (March 1, 2014)

The JAEA starts the researcheson the dry storage.

Establishment (September 19, 2012)

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New Regulation for the Storage Facilities

2015 5Ref: Home page of NRA (https://www.nsr.go.jp/)

Enforcement on December 18, 2013RFS submitted an application document to the NRA in compliance with new

regulatory requirements on January 15, 2014.

New Basic Energy Plan

2015 6

Cabinet Approval of the New Basic Energy Plan Nuclear power will be positioned as an important baseload power source

and the nuclear fuel cycle will continue to be promoted.

The government will lead the efforts for final disposal of high-levelradioactive waste.

Open solicitation of municipalitiesThe repository site selection process

New approach led by the government

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Operational Status

2015 7http://www.nsr.go.jp/english/nuclearfacilities/

Mutsu

Under Re-design

Mutsu

Kansai EPCO

Kyushu EPCO

Source: Recyclable Fuel Storage Company

(Photos of August 30,2013)

Current situation of Mutsu site

2015 8

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Operational Status

2015 9http://www.nsr.go.jp/english/nuclearfacilities/

MutsuMutsuOhmaUnit 1&2

Unit 1

Unit 1

Unit 1

Unit 1&2Unit 1&2

Fuel Removal of Fukushima Daiichi NPP

2015 10

Before Tsunami

Temporary Storage Equipment（28/50 casks ）

Cask Inspection

Number oftransferredassemblies

1533/1533As of Dec.22, 2014

Number of times of cask transportation : 71Spent Fuel: 1331/1331 Fresh Fuel: 202/202

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Contents1.Regulatory and Operational Status2. Japanese studies on the Spent Fuel Storage3. Summary

2015 11

2015

Sea

給気温度33℃

排気温度98℃

一次蓋・二次蓋溶接

胴部-底部溶接

0.8～1 m/s

Air Outlet

Air Inlet

Measurement of sea salt in air andsalt deposition rate (by CRIEPI)

0.01

0.1

1

10

100

1000

10000

1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07

Deposition of Salt（mg/m

2as C

l-）

Tim e（h）

1.4m /s, 30℃

1.4m /s, 100℃

0.85m /s, 30℃

0.3m /s, 30℃

1.4m /s, 200℃

Field test

（30℃、10 m g/m 3）

tQin 07.5

tQout 0892.0（30℃、2 μg/m 3）

0

20

40

60

80

100

120

0 50 100 150 200 250 300

電気

伝導

率（μ

S/cm）

時間（h）

H23.8.31-9.10

H23.9.10-9.20

H23.9.20-9.26

H23.9.30-10.11

H23.10.11-10.21

H23.10.25-11.4

Time (h)

Ele

ctric

al C

ondu

ctiv

ity (

μS/c

m)

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2015 13

SCC Test using Mock-up MPC Model (by CRIEPI)

• Verify the effectiveness of the surface treatment technique MPC of Ring type with full-scale diameter (1,832mm) and wall thickness

(16mm) Part of the weld line were treated by LPB 4g/m2 as Cl , 80˚C with RH=35% for 5000 hours The existence of the SCC will be checked

NozzleWeld Line（Lid）

Masking

Spray ofArtificial SeaWater

Mockup

Weld line（Canister Body）

LPB

Inspection Technology for Canister Surface (by CRIEPI)

• Inspection of the occurrence of SCC Evaluation of the deposition of chloride attached on canister

during storage Development of the laser measurement system

Threshould Value for SUS304L

I Clno

rmali

zed

by I O

Cl Concentration (g/m2)

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Canister

Sensor head

Optical probe

2015

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Monitoring Technology for Canister Confinement (by CRIEPI)

Canister

TB

TT

Ref: H.Takeda, Development of the detecting method of helium gas leak from canister, Nuclear Engineering and Design 238 (2008)D.Toriu, Development of monitoring system of helium leakage from canister, GLOBAL2013

2015 15

Demo Test of PWR Spent Fuel (by Electric Power Companies)

2015 16

Nuclear Safety Commission requested utilities to accumulate knowledge andexperience on long-term integrity of spent fuels during dry storage 2 AR storage facilities of BWR SFs have been already operating. No dry storage experience for PWR SFs

Test Program by PWR Utilities Loading 2 PWR SFs

(48 and 55GWd/t) Periodically analysis 85Kr Gas Composition

Monitoring during storage Surface temperature Boundary Pressure

License Approval The test will start in 2015.

End of TestInspection of fuelafter storage test

Increase of Kr-85 level

[ 48GWd/t fuel ]

– Visual inspection of fuel assembly

– Kr-85 radioactivity analysis– Gas composition analysis– Monitoring of surface temperature

of test container– Monitoring of containment

boundary pressure of test container

Loading to test container** The following inspections of sampledcavity gas are to be carried out at thestart of storage test after fuel loading;– Kr-85 radioactivity analysis– Gas composition analysis

Inspection of fuelbefore storage test

Start of Storage Testunder Dry Condition

Inspection of fuelbefore storage test

[ 55GWd/t fuel ] Loading to testcontainer*

- Visual inspection of fuel assembly

– Visual inspection of fuel assembly

10 years

Pause of TestInvestigation of cause

Analysis and monitoringduring storage test

End of TestInspection of fuelafter storage test

Increase of Kr-85 level

[ 48GWd/t fuel ]

– Visual inspection of fuel assembly

– Kr-85 radioactivity analysis– Gas composition analysis– Monitoring of surface temperature

of test container– Monitoring of containment

boundary pressure of test container

Loading to test container** The following inspections of sampledcavity gas are to be carried out at thestart of storage test after fuel loading;– Kr-85 radioactivity analysis– Gas composition analysis

Inspection of fuelbefore storage test

Start of Storage Testunder Dry Condition

Inspection of fuelbefore storage test

[ 55GWd/t fuel ] Loading to testcontainer*

- Visual inspection of fuel assembly

– Visual inspection of fuel assembly

10 years

Pause of TestInvestigation of cause

Analysis and monitoringduring storage test

Ref: A.Otsuka et. al, Demonstration Test Program for Long-term DryStorage of PWR Spent Fuel, Proceeding of GLOBAL2011

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3. Summary・Japanese utilities submitted applications to the NRAto restart the twenty plants.・Sendai NPP obtained the permission from the NRA.But, no nuclear power plant works.・RFS submitted applications to the NRA.・Removal of Spent Fuel in the Pool of Unit 4 atFukushima Daiichi Site were completed.・Cabinet adopted the New basic Energy Plan.・CRIEPI are continuing the study on the SCC of canister.

2015 17