Summary of 12th Technical Conference
1. Date:September 1, 2016 (Thur.) 15:00 ～ 17:30

2. Place:

Board Room, Otemachi Headquarters, Central ResearchInstitute of Electric Power Industry
3. Participants:
Chair: Yokoo（NRRC）
Members: Furukawa (Hokkaido EPCO, substitute for Maki), Obonai (TohokuEPCO, substitute for Kato), Igarashi, Kawamura (Tokyo EPCO),Nakagawa, Nagura (Chubu EPCO), Kuwahara (Hokuriku EPCO,substitute for Takahashi), Oishi, Suzuki, Urata (Kansai EPCO,substitute for Yoshihara), Hayashi (Chugoku EPCO, substitute forIwasaki), Nishimura (Shikoku EPCO, substitute for Kawanishi),Okano (Kyushu EPCO), Ishizaka (JAPC), Okamura (JNFL),
Kuramoto (J-Power), Noda (Toshiba), Konno (Hitachi-GE), Kono(MHI), Kurata (JANSI), Takahashi, Shimeno, Zama, Sakai, Ueda,
Yamamoto (NRRC)
Observer: Ono (FEPC), Apostolakis, Omoto (NRRC)
4. Proceedings:(1) Tentative R&D Plan for FY2017
NRRC made a presentation on the tentative R&D plan for FY2017.
(2) Tentative Action Plan of RIDM Promotion TeamThe RIDM promotion team presented its major near-term activities.
（Remarks from members）（◆Industry members, ◇CRIEPI members）◆We expect much contribution from the activities and the strategic plan of
the RIDM team. It is important to promote NRRC’s various R&D activities
as a concerted effort based on this strategy so that we can make steadyprogress in the practical application at the sites.
◇As the RIDM team starts developing a strategic plan, NRRC can obtain aclearer understanding of each R&D such as when and where the output ofR&D will be applied. Also, as we have made progress in PRA development,

we have become aware of a new task to connect internal event PRA models
and external natural event PRA models. In this context, NRRC’s
individual teams must work in a closer collaboration.
◇So as to provide research outcomes in a more timely manner, we are
discussing enhanced release of interim results in addition to the final
output. (Apostolakis)◇ We are engaged in the Senior Seismic Hazard Analysis Committee(SSHAC) process for the Ikata 3 pilot project. It is an effort to demonstrate
the process which has a proven track record in the US. It also represents afirst opportunity for Japanese and US experts to develop a seismic hazard
evaluation method in Japan by introducing a probabilistic approach.
◆We expect that insights and information gained from the demonstration ofthe SSHAC process will be shared by all utilities.
(3) Discussion with NRRC Head
（Remarks from NRRC Head）◇It was an issue of controversy in the US whether or not to integrate theinternal event PRA models and external event PRA models because theevaluation of external events entails far greater uncertainties incomparison to the internal event PRA. But, from a practical viewpoint ofrisk management, we must concentrate on the high probability area in theprobability distribution of CDF, not on extremely low numbers such as 10-9
or 10-10. (Apostolakis)◇Whenever the topic of risk-informed regulation came up in the US, some
focused only on the shortcomings or deficiencies of PRA, without
mentioning similar problems of the deterministic approach. But it is only
PRA that could identify the specific accident sequences in a loss of all AC
power event and also highlight the importance of support system andhuman error. We must recognize there is no perfect regulatory system andeach system (probabilistic and deterministic) has its own advantages anddisadvantages. (Apostolakis)