Summary of the 1st Technical Advisory Committee (TAC) Meeting
1. Date:Oct. 27 (Mon), 2014 － Oct. 31 (Fri), 2014

2. Place:
Central Research Institute of Electric Power Industry (CRIEPI)
3. Participants: TAC; Mr. Stetkar (Chair), Mr. Afzali (Member), Dr. Chokshi(Member)Prof. Takada (Member, Partially attended),Prof. Yamaguchi (Member, Partially attended)
CRIEPI; experts of Nuclear Risk Research Center,Industry; experts of Shikoku EPCO, Tokyo EPCO, Kansai EPCO and
Mitsubishi Heavy Industry (MHI) for respective topics
4. Proceedings
The agenda of the 1st TAC meeting was developed by Dr. Apostolakis, the Head ofNRRC and Mr. Stetkar, the chair of TAC. Topics were selected based on thefollowing three objectives.
1) To explore the current situation of Probabilistic Risk Assessment (PRA) as
applied in Japan in order to support Japanese utilities’ efforts to utilize PRA
more intensively2) To discuss the NRRC research plan and provide advice to NRRC
3) To discuss how to proceed with the key issues of NRRC R&D focused on theneeds of electric utilities
Oct. 27 (Mon)At the opening of the meeting, Mr. Stetkar stated his views regarding the guidanceof TAC as follows.
・The formal statements of TAC will be developed by its six members includingthe chair.
・If there is a difference of opinion among members, a formal statement of TAC
will require the agreement of four or more members. However, in that case,minority opinions may be included in the TAC report.
・TAC will submit a report of the discussion result to the head of NRRC. This
report will be posted on the NRRC website, except when proprietary mattersor matters relevant to security are discussed.
The basic rules of TAC including the above will be fixed at the next TAC meeting
after hearing opinions from all TAC members.
Topic 1: Utility safety upgrade beyond Regulatory Requirements.
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・The outline of the voluntary safety improvement by Japanese electric industry
was presented by NRRC.
(Handouts)
Utility safety upgrades beyond Regulatory Requirements.
Topic 2: Level-1 internal event PRA models for Ikata Unit 3, Shikoku EPCO
・MHI presented the PRA model attached in the application documents for theconformity assessment of Ikata Unit 3, based on the new regulatory
requirements.
・MHI explained that this PRA model does not include the equipment for“Accident Management” because the regulators require that the model beconstructed with only the equipment described in the previous conformity
assessment.
(Handouts)
Probabilistic Risk Assessment (PRA) for Unit 3, Ikata NPP / Level 1 Internal
Event PRA during At-Power Operation and Shutdown
Oct.28 (Tue)Topic 3: Level-1.5 internal event PRA models for Ikata Unit 3, Shikoku EPCO
・ MHI presented the Level 1.5 internal event PRA models attached in theapplication documents for the conformity assessment of Ikata Unit 3, based on
the new regulatory requirements.
・In addition to the above, the Level 1 and Level 2 PRA models that were used byShikoku EPCO for the Periodic Safety Review (PSR) in 2002 were also presented
as candidates for the foundation of the PRA improvement.
(Handouts)
Probabilistic Risk Assessment (PRA) for Unit 3, Ikata NPP / Level 1.5 Internal
Event PRA during At-Power Operation
Ikata Unit 3 Level 1 PRA, At-Power with Accident Management
Ikata Unit 3 Level 1 PRA, Low Power and Shutdown with Accident Management
Ikata Unit 3 Level 2 PRA, Event Tree with Accident Management
Ikata Unit 3 Level 2 PRA, Table No. 4.2.6-3, Containment Event Tree Branching
Probability
Topic 4: Plant Walkdown
・As the one of the key issues for NRRC R&D based on the electric utilities’ needs,2the current practices of “Plant Walkdown” in Tokyo EPCO, Kansai EPCO, andShikoku EPCO were presented.
(Handouts)
None.
Topic 5: Human Reliability Analysis (HRA)・Human Reliability Analysis (HRA) was selected as one of the key issues for NRRC
R&D based on the electric utilities’ needs. The idea of developing a guideline forHRA was presented by NRRC.
(Handouts)
Research Plan of Develop HRA Procedure GuideOct. 29 (Wed)Topic 6: Seismic and Tsunami PRA for Ikata Unit 3
・MHI presented the seismic PRA model and the tsunami PRA model used in theapplication documents for the conformity assessment of Ikata Unit 3, based on
the new regulatory requirements.
・There were some questions and answers about the details. Due to the time
constraints, the discussion will be continued in the January 2015 TAC meeting.
(Handouts)
Probabilistic Risk Assessment (PRA) for Unit 3, Ikata NPP / Level 1 Seismic andTsunami PRA during At-Power Operation

Topic 7: External Event PRAs of Kashiwazaki-Kariwa
・Tokyo EPCO presented the seismic PRA model and the tsunami PRA model usedin the application documents for the conformity assessment
Kashiwazaki-Kariwa Unit 7, based on the new regulatory requirements.

of(Handouts)
External Event PRAs of Kashiwazaki-Kariwa NPS
Topic 8: NRRC’s PRA development plan for Ikata Unit 3
・NRRC presented the contents of the research project on Ikata Level 2 seismic PRA
sponsored by METI (Ministry of Economy, Trade and Industry).
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(Handouts)
NRRC’s PRA Development Plan for Ikata Unit 3
Oct. 30 (Thr)
Topic 9: NRRC Research Plan 2014-2015
・NRRC presented the outline of its research plan and the contents of major
research items.
・Additional details of the research plan and priorities will be discussed during theJanuary 2015 TAC meeting.
(Handouts)
Road map & Working Plan (2014-2015) for Risk Assessment team in NRRC
Research Plan on Risk Assessment area (WG1) Offsite EffectResearch Plan (2015fy) of the Plant Thermal-hydraulics unit
Study on Risk Communication
Internal & Seismic-induced Fire and Flooding PRA
Research Plan on Natural External Event Assessment Area (NRRC-WG2)
Oct. 31 (Fri)Topic 10: State of knowledge on Multi-Unit PRA
・NRRC presented the current knowledge on the multi-unit PRA.
(Handouts)
State of the Knowledge on Multi-Unit PRA / Floor and System/Components
Response4