decommissioning of nuclear power plantyankee rowe nuclear power plant before after decommissioning...
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The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
GROUP A
Decommissioning of Nuclear Power Plant
Auguest 2nd, 20191
2019 Maintenance Science
Summer School
presenter:土屋克嘉 Katsuyoshi Tsuchiya張孫易 Sun-Yi,CHANG蔡謹年 Ching-Nien,TSAI鄭雅云 Ya-Yun,CHENG施湘鈴 Hsiang-Ling,SHIH小松啓祐 Keisuke Komatsu小嶋拓実 Takumi Ojima
中野雅紀 Masanori Nakano
The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
Outline
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IntroductionDecommissioning of nuclear power plantThree decommissioning strategiesAnalyzing Pros and ConsFlow chart of decommission
Waste Management in Japan Current situation in Japan Waste Management in Taiwan Current situation in Taiwan Conclusions
The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
Decommissioning of nuclear power plant
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What is “ decommissioning” ?Decommissioning is the process by which nuclear power plants are retired from service. Decommissioning is the final stage in the life of nuclear power plants.
Why do the nuclear power plants need to be decommissioned ?1) no economic benefits2) end of life3) outdated technology4) Termination of operational tasks5) changes in government policies 6) serious accident
The most important purpose of decommissioning is to remove the regulatory controls from facility, and then we can start reusing the site.
2019 Maintenance Science
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The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
Three decommissioning strategies
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Immediate dismantling Commence shortly after the nuclear power plant stop operating.Ex. France, Japan (JPDR)
Deferred dismantlingDismantling may be deferred for a period of up to several decades.Ex. England
Entombment The remaining radioactive material is permanently encapsulated on site.Ex. Russia (Chernobyl Nuclear Power Plant)
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The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
Analyzing Pros and Cons
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Immediate dismantling Deferred dismantling
Duration Longer Shorter
Waste management [ton] More fewer
Cost More expensive cheaper
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2019 Maintenance Science
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Cost Estimation
Risk Analysis
Project Scheduling Dismantling Waste Management
Decontamination
Site Remediation& Reuse
Start of decommissioning CompletionTime line
The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
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Yankee Rowe Nuclear Power Plant
afterbefore
The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
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2019 Maintenance Science
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: generated from decommissioning activities
Radioactive waste
High level waste(HLW) Low level waste(LLW)
L1 waste L2 waste L3 waste
Radioactive levelHigh Low
Amount generated ManyFew
・Spent fuel (Used radioactive materials)
・Materials contaminated by radioactive materials.
・Tools used for dismantling.
What’s radioactive waste ?
The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
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2019 Maintenance Science
Summer SchoolWaste Management in Japan
HLW is generated as below
Nuclear power plant
Spent fuel
Reprocess
UraniumPlutonium
About 95%
About 5% HLW
solidified glass body
Reuse for fuel
The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
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2019 Maintenance Science
Summer SchoolCurrent situation in Japan
HLWIn Japan, we partition spent fuel into uranium and plutonium and HLW.
LLWIn Japan, we divide LLW into 3 types L1, L2 and L3 depending on its value of radioactivity.
Treatment ProblemHLW Be disposed of There are no final repositoriesUranium and plutonium Be reused as fuel Reprocessing plant stops operation now
Disposal way Main player Radioactivity criteria[1],[2] (examples)L1 Subsurface disposal Japan Nuclear Fuel
Limited(JNFL)α nuclide ≤ 100 GBq/ton
L2 Pit disposal JNFL α nuclide ≤ 10 GBq/tonCo-60 ≤ 1 PBq/ton
L3 Trench disposal Electric power plant Co-60 ≤ 10 GBq/ton
[1]原子炉等規制法施工令,[2]第二種廃棄物埋設事業規則
The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
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2019 Maintenance Science
Summer SchoolWaste Management in Taiwan
HLW
ILW
LLW
VLLW
EW
VSLW
ILW
Class-A
LLW
Greater than Class-C
Class-B & Class-C
HLW
EW
Activ
ity
Half-life
IAEA TAIWAN
The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
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2019 Maintenance Science
Summer SchoolWaste Management in Taiwan
The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
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2019 Maintenance Science
Summer SchoolCurrent situation in Taiwan
Immediate dismantlementTime limit of decommissioning : 25 yrs ( Dec,2018 – Dec,2033 )
Jinshan Nuclear Power Plant
Capacity of spent fuel
pool (assemblies)
Unit 1 3074 / 3083
Unit 2 3076 / 3083
Spent fuel pool is full.Dry storage system can not be operated. Environment issues
Final disposal site has not been determined yet.
the fuel can not be removed from the core.
Jinshan
The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
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2019 Maintenance Science
Summer SchoolCurrent situation in Taiwan
In Taiwan, some of low-level radioactive waste is temporarily stored in the Lanyu temporary storage site. The other is stored in the low-level waste storage plant in each nuclear
power plant.
The permanent storage site was undecided because the local government refused to cooperate with the referendum of low-level waste final disposal site selection.
The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
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2019 Maintenance Science
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The most important purpose of decommission is to remove the regulatory controls from facility, and then we can start reusing the site.
The options of waste management will significantly influence on the following project of decommission.
In Japan, deffered dismantlement has been adopted for NPPs which are under decommissioning.
In Taiwan, deffered dismantlement is a more suitable solution than immediate dismantlement.
The Electrochemistry Lab, Department of Engineering and System ScienceNational Tsing-Hua University
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2019 Maintenance Science
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[1] https://www.nei.org, Nuclear Energy Institute[2] https://www.taipower.com.tw/tc/index.aspx, Taiwan Power Company[3] https://www.aec.gov.tw, Atomic Energy Council[4] Selection of decommissioning strategies: Issues and factors, IAEA[5] https://www.iner.gov.tw, Institute of Nuclear Energy Research [6] https://www.numo.or.jp, NUMO VISION
Thanks for your attention!
Q&A
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