0 Experience of improvement of Nuclear Regulation in Japan Yutaka HARA Director, International Affairs Office Nuclear Regulation Authority (NRA) JAPAN 20 September 2017, IAEA GC 2017 “Effective Partnerships for Nuclear Safety and Security in the Arab Region” , Vienna
1 Ⅰ New regulatory requirements on Lessons Learned
2 New Requirements Based on Lessons Learned Large scale common cause failures due to extreme natural hazards led to long lasting SBO / LUHS , resulting in severe accidents . SBO: Station Blackout LUHS: Loss-of Ultimate Heat Sink Enhanced measures against natural hazards Not only earthquakes and tsunamis but also volcanic activities, tornadoes, forest fires, etc. Enhanced reliability of safety functions such as power supply Use of mobile equipment, strengthened “ diversity ” Mandatory measures against severe accidents Prevention and mitigation of core damage Suppression of radioactive materials dispersion Back-fitting to existing plants
3 Comparison between Previous and New Requirements <Previous requirement> <New requirement> (Against SA* & Terrorism) Response to intentional aircraft crash Suppression of radioactive materials dispersal 4 th Layer New of DiD* Prevention of CV failure & large release Prevention of core damage Design basis to prevent severe accidents (Postulate multiple failures) (Confirm that a single failure would not Internal flooding (New) lead to core damage) Reinforced Fire protection & New 3 rd Layer of DiD Fire protection Reliability of power supply Reliability of power supply Function of other SSCs Function of other SSCs* & New Reinforced Natural phenomena (Volcano, Tornadoes, Forest fire: New) Natural phenomena Seismic / Tsunami resistance Seismic / Tsunami resistance DiD* : Defense in Depth SSCs*: Structure, Systems and Components SA* : Severe Accident
4 (Example) Measures against Tsunamis Accurate Evaluation Method on Earthquake and Tsunami ; Particularly Enhanced Tsunami Measures More stringent standards on Define “Design Basis Tsunami” that exceeds the largest in the historical records and require to take protective Tsunami measures such as breakwater wall based on the design basis tsunami Enlarged application of higher SSCs for Tsunami protective measures are classified as seismic resistance Class S equivalent to RPV* etc. of seismic design importance classification *RPV: Reactor Pressure Vessel ＜ Example of tsunami countermeasures （ multiple protective measures ）＞ Breakwater Wall Tsunami Guard (prevent inundation to the site) (prevent water from flowing into the building) Tsunami Guard
Status of Conformity Review for Nuclear Power Plants 5 As of 1 September 2017, 16 PWRs and 10 BWRs have filed application. Five PWRs are in operation. (Sendai 1&2, Ikata 3 and Takahama 3&4 ) ＜ Tomari ＞ PWR (20) ＜ Kashiwazaki Kariwa ＞ BWR (22) BWR, under ＜ Shika ＞ ＜ Ohma ＞ Construction Specified ＜ Higashidori(TEPCO) ＞ nuclear facility ＜ Higashidori(Tohoku Co.) ＞ ＜ Tsuruga ＞ Reactors undergoing decommissioning (9) ＜ Onagawa ＞ + Applied (26) ＜ Mihama ＞ Restarted (5) ＜ Fukushima Dai-ichi ＞ ＜ Ohi ＞ ＜ Fukushima Dai-ni ＞ ＜ Takahama ＞ Application ＜ Tokai Plant, Tokai Dai-ni ＞ PWR 16 ＜ Shimane ＞ ＜ Hamaoka ＞ BWR 10 ＜ Ikata ＞ Total 26 ＜ Genkai ＞ ＜ Sendai ＞
6 Ⅱ Continuous Improvement of Nuclear regulation
7 • Continuous improvement of ordinances and guides - Amendments of NRA ordinances and guides will be continuously done through the NRA’s improvement process of regulation based on new knowledge and experience. - For Example Single-phase open circuit Toxic gas releases HEAF: High Energy Arcing Faults
8 • Back-fitting - New regulatory requirements are being back- fitted to the existing plants under the legal framework • New requirements based on the lessons learned from the Fukushima Daiichi accident • Amendments of the requirements triggered by operating experience and new technical knowledge
9 Ⅲ IRRS Mission
10 Overview of IRRS Mission in 2016 Date: 11-22 Jan, 2016 , including other stakeholders’ interviews and site visits In IRRS Mission report, 2 good practices, 13 recommendations and 13 suggestions are indicated. ⇒ NRA has responded to them in an effective manner since right after receiving these. Responses Major items NRA has been working to introduce NRA’s new inspection system and Inspection Program amended the Reactor Regulation Act in 2017. NRA has been working on strengthening RI security and clarifies the Regulation for responsibility of RI users etc. and also amended the Radioisotope Radioisotope (RI) Regulation Act in 2017. Human Resource NRA started a plan to increase and secure qualified staff as well as to improve NRA’s education and training system for expertized personnel. Development NRA improved and systematized its management system to more Management System sophisticated one.
11 Benefits gained from IRRS Mission IRRS is used as an effective tool to strengthen nuclear safety in Japan ( Ex. A cts were amended to enhance NRA’s regulation. ) NRA gained international knowledge and practice through discussion with IRRS reviewers. NRA developed its knowledge and understanding of IAEA standards through the self assessment for IRRS. The following points are important: Conduct IRRS mission on a regular basis to find challenges for nuclear safety Conduct Follow-up mission (after summer in 2019 ) (Japan did not host a follow-up mission after the IRRS mission in 2007)
12 Ⅳ Conclusion NRA was established under the lessons learned from Fukushima Daiichi Accidents just five years ago. NRA has been pursuing and will pursue “continuous improvement of safety”. NRA will make efforts to further enhance nuclear safety and security in Japan through IAEA peer review services (IRRS and IPPAS Follow-up Missions a few years later.). NRA would share experiences with other countries through opportunities such as IAEA GC side-events, RCF activities, review meetings of JC/CNS, safeguard training programs supported by IAEA/ MEXT and other IAEA TMs.
13 Thank you for your attention. http://www.nsr.go.jp/english/ 13
14 Appendix
15 NRA’s Commissioners As of September 22 2017 Chairman Toyoshi Fuketa Commissioner Commissioner Commissioner Commissioner Nobuhiko Ban Shinsuke Yamanaka Akira Ishiwatari Satoru Tanaka
16 Organizational Chart of the NRA Secretariat As of July, 2017 The Secretariat of the NRA Number of staff: about 1,000 Secretary-General Deputy Secretary-General for Technical Affairs Deputy Secretary-General (Chief Engineering Officer) Secretary- General’s Secretariat Nuclear Regulation Department Director-General for Director-General for Radiation Protection Director-General, Nuclear Strategy and Security Emergency Response Regulation Department Director for Cybersecurity and Director-General (3) Information Technology Nuclear Regulation Policy Policy Planning and Planning Division Radiation Protection Regulatory Standard and Coordination Division Fire Management Office Research Department Department Management SystemOffice Licensing Regulatory Standard and Public Information Office Radiation Protection Public Research Division Policy Planning Division International Affairs Office Divisions of Licensing(4) *2 Safeguards Office Divisions of Accidents Response Office Research(4) *1 Radiation Monitoring Oversight Division Litigation Office Division of Oversight Planning and Nuclear Security Coordination Division Personnel Division Division of Budget Division of and Accounting Divisions of Oversight(3) *3 Division of Legal Affairs Regulation for Radiation *1 Research for Reactor System Safety, Research for Severe Accident, Research for Nuclear Fuel Cycle and Research for Radioactive Waste, Earthquake and Tsunami *2 Licensing for Nuclear Power Plants, Licensing for Research Reactors, Use of Nuclear Material and Specified Nuclear Facilities, Licensing for Nuclear Fuel Facilities, Licensing for Earthquake and Tsunami Measure *3 Oversight of Nuclear Power Plants, Specified Oversight, Oversight of Nuclear Fuel Related Facilities and Research Reactors
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