Summary of the 3rd Technical Advisory Committee (TAC) Meeting
Date:
Place:

May 25 – 29, 2015
Central Research Institute of Electric Power Industry

Participants:
TAC:
Mr. Stetkar (Chair), Mr. Afzali, Dr. Chokshi, Mr. Pouget-Abadie,
Prof. Takada, Prof. Yamaguchi
NRRC:
Dr. Apostolakis (Head), Experts of Nuclear Risk Research CenterIndustry:
Representatives of Federation of Electric Power Companies (FEPC),
Experts of Shikoku EPCO for respective topics
Proceedings
TAC and NRRC agreed that some technical topics would be discussed in focusedsessions. The purpose of the focused sessions was to examine details of specifictopics that could not be covered in the same depth during the Full Committee
briefings. Focused sessions were conducted in parallel in the morning andafternoon on Tuesday, May 26, and in the morning on Wednesday, May 27. TAC
members attended the focused sessions according to their respective areas oftechnical expertise.
The Full Committee briefings were conducted in theafternoon on Monday, May 25, the afternoon on Wednesday, May 27, and on
Thursday, May 28. All TAC members participated in the Full Committee
briefings.

May 25 (Mon.)
Full Committee: Topic 1: Japan PRA Standard for Internal Events• NRRC explained the Japanese Level 1 PRA standard for internal events.
(Handouts)
1-1. AESJ - Standard for Level 1 PRA during power operation
1-2. Amendment of Standard for Procedures of Level 1 PRA

Full Committee: Topic 2: Japan PRA Standards for External Events• NRRC explained the Japanese PRA standards for seismic and tsunami events.
(Handouts)
12-1. AESJ - Implementation Standard for Seismic PSA
2-2. AESJ - Implementation Standard Concerning the Tsunami PRA

May 26 (Tue.)
Focused session: Group 1: Topic 3: Ikata 3 PRA Event Trees and Fault Trees••In response to the questions asked by Mr. Stetkar after the 2nd TAC meeting,Shikoku EPCO answered a list of technical questions about Ikata Unit 3 EventTrees.
Mr. Stetkar stated that follow-up questions about the Ikata Unit 3 Event Trees
and new technical questions from the review of the Ikata Unit 3 Fault Trees
would be sent after this meeting.

(Handout)
3-1. Ikata 3 PRA Event Trees and Fault Trees
3-1. (Attachment). Response to Mr. Stetkar’s Comments

Focused session: Group 1: Topic 4: Ikata 3 PRA Project Plan• Shikoku EPCO presented the detailed plan, schedule, and specific tasks for theIkata Unit 3 PRA project.
(Handouts)
4-1. Ikata 3 PRA Project Plan
4-2. AESJ - Standard for ensuring quality of PRA (Excerpt from the chapter on PRAPeer Review)

Focused session: Group 2: Topic 5: Ikata 3 PRA Seismic Hazard Analysis Methods• Shikoku EPCO reported on the current status of investigations for use of theSenior Seismic Hazard Analysis Committee (SSHAC) process in the Ikata Unit 3project.
• TAC members commented that it is important for parties involved in theSSHAC process to have common and clear understanding of probabilistic hazard
assessment methods and the SSHAC process.
(Handout)
5-1. SSHAC Application for the Seismic Hazard Assessment for Ikata Unit 32

Focused session: Group 2: Topic 6: Ikata 3 PRA Seismic Fragility Analysis Methods• NRRC presented the JAERI method as an analytical method for producing
seismic fragilities for the Ikata Unit 3 PRA.
• TAC members commented that uncertainty should be evaluated appropriatelyin the fragility analysis.
(Handout)
6-1. Seismic fragility analyses to be performed for Ikata 3 PRA

May 27 (Wed.)
Focused session: Group 1: Topic 7: Ikata 3 PRA Data
• Shikoku EPCO presented the methods and plan for collecting and assessing
plant-specific data.
• TAC members advised Shikoku EPCO to have enough time to decide on thescope of data collection and prepare so that the data collection can be done only
once, because additional data collection after finishing the original work would
be a large effort.
(Handout)
7-1. Ikata 3 PRA Data Analysis

Focused session: Group 2: Topic 8: Ikata 3 PRA Tsunami Hazard Methods• Shikoku EPCO presented procedures for tsunami hazard analysis for Ikata Unit
3.
(Handout)
8-1. Ikata Nuclear Power Station (Tsunami Evaluation - probabilistic tsunamihazard assessment)

Full Committee: Topic 9: Ikata PRA Scope and Project Plan
• Shikoku EPCO presented the tentative scope of PRA which is underconsideration for the submission of the first Safety Analysis Report (SAR) andthe detailed plan of the Ikata Project. It was also confirmed that the topics ofdiscussion in TAC meetings should be determined based on the requests by
NRRC and/or utilities.
3•

TAC members commented that the Ikata project should be conducted to bringthe PRA to the international state of the practice independently of the SARprocess. NRRC added that research conducted by the NRRC and the industry
will push the Ikata Unit 3 PRA beyond the state of the practice in certain areas.
It was agreed that TAC would be offering recommendations to bring the Ikata
PRA, at a minimum, to the international state of the practice. The SAR process
will be outside the scope of TAC’s deliberations. It was also agreed that theconcepts of "state of the practice" and "state of the art" will be discussed andclarified further at the next TAC meeting in Tokyo.

(Handouts)
Same as Topic 4

May 28 (Thu.)
Full Committee: Topic 10: Ikata PRA Seismic Hazard and Fragility Analyses• Shikoku EPCO reported on the SSHAC process application study for the Ikata
Unit 3 project.
(Handouts)
Same as Topics 5 and 6

Full Committee: Topic 11: Ikata 3 PRA Tsunami Hazard••

Based on the comments in the focused sessions, it was agreed that NRRC will
increase priority for the combination of seismic and tsunami hazards, rather
than performing a separate evaluation of only tsunamis.
TAC members commented that the Ikata site has a relatively low tsunamihazard. It was noted that this analysis methodology should be applied at othersites to confirm the reliability of the method.

(Handout)
Same as Topic 8

Full Committee: Topic 12: Ikata 3 PRA Data Analysis•Shikoku EPCO presented the process to collect Ikata NPP plant-specific data
and the method of collecting failure data by using the Enterprise AssetManagement (EAM) system.
4•TAC members commented that data for equipment failures and maintenancetimes should be available from the sources that were discussed. However,additional effort may be needed to compile consistent data for the respective
equipment operating times and demands.

(Handout)
Same as Topic 7
Full Committee: Topic 13: Japanese Industry Safety Goals for Multi-Unit Sites• NRRC presented the preliminary concept and plan to consider JapaneseIndustry Safety Goals.
• TAC was supportive of this effort.
(Handout)
13-1. Japanese Industry Nuclear Safety Goals for Multi-Unit Site

Full Committee: Topic 14: Cabinet Fire Experiments and NRRC Research Plan••NRRC presented the issues on fire PRA and the status of fire testing research.
TAC members commented that fire tests should be executed in more realistic
conditions and discussed topics that should receive priority.

(Handout)
14-1. Fire Test Research and Fire PRA of Japan

Full Committee: Topic 15: Human Reliability Analyses• NRRC presented the near-term target of HRA and asked TAC to give advice.
• TAC members agreed that Option 2 of the NRRC presentation should beimplemented in the near-term, pending further research on evolving HRA
methods. Option 2 means to upgrade the current HRA methods by using theEPRI HRA calculator with enhanced guidance for the scenario narratives.
(Handout)
15-1. NRRC’s HRA Upgrade5