Overview of Regulations and Guides in Japan

Transcription

1 Technical Meeting on Novel Design and Safety Principles of NPPs Overview of Regulations and Guides in Japan IAEA, Vienna, Austria 3-6 October 2016 Tsuyoshi Nakajima Regulatory Standards and Research Division Nuclear Regulation Authority (NRA-Japan)

2 Contents i. Japan Update ii. Overview of the New Regulation iii. Practical Elimination and Safety Goal iv. Review Guide for Severe Accident Measures v. Continuous Improvement for Safety vi. Conclusions 1

3 i. Japan Update 2

4 Timeline and Current Status The NRA was established in Sep and urgently started developing the new regulatory requirements for NPPs which came into force in July After the 1F accidents, all the 48 units had suspended their operation one by one by May units (16 PWRs, 10 BWRs) have applied for conformance review to the new requirements NRA has granted the permissions for 7 units: Sendai-1, -2, Takahama-1~-4 and Ikata-3 Sendai-1, 2 and Ikata-3 in operation IPPAS mission s review was done in Feb IRRS mission s review was done in Jan

5 Nuclear Power Reactors in Japan Application of Conformity Review for NPPs PWR (24) <Tomari> <Kashiwazaki-Kariwa> Application BWR (24) BWR, under Construction (2) Specified nuclear facility Already Service Terminated (6) Reactors undergoing decommissioning (3) <Shika> <Tsuruga> <Mihama> <Ohma> <Higashidori> <Onagawa> PWR 16 BWR 10 Total 26 As of Oct, 2016 Applied (26) <Fukushima Dai-ichi> Restarted (3) <Ohi > <Fukushima Dai-ni> <Takahama> <Tokai Plant, Tokai Dai-ni> <Shimane > <Hamaoka> <Ikata> <Genkai > <Sendai > 4

6 Application of Conformity Review for FCFs and RRs Licensee Facility JNFL Reprocessing /Uranium Enrichment /MOX Fuel Fab /High-Level Radioactive Waste Storage Center RFS JAEA MNF NFI GNF-Japan Spent Fuel Storage Facility (Interim Storage) Oarai R&D Center (Waste Management Facility) Uranium Fuel Fab. Facility (PWR) Uranium Fuel Fab. Facility (Tokai(BWR)/Kumatori(PWR)) Uranium Fuel Fab. Facility (BWR) Kyoto Univ. RRs (KUR/KUCA) Kinki Univ. JAEA JAEA RR RRs(JRR-3/NSRR), STACY, R&D facility Oarai R&D Center, RRs (HTTR/JMTR) 5

7 ii. Overview of the New Regulations 6

8 Revision of the Reactor Regulation Act Overview 1. NRA can issue rules and permissions as the RB 2. Back-fit system: No difference from new and existing NPPs Moratorium may be decided when the additional requirement established Specialized Safety Facility 5 years moratorium 3. Clarification of the Primary Responsibilities for operators 4. Evaluations to improve the safety of NPPs: Periodically Update as FSAR 5. Limits on the operation period: 40 years only one extension up to 20 years if approved by the NRA 7

9 Structure of New Regulatory Requirements Req. for AOOs and DBAs were strengthened. Req. for SAs that are equivalent to DECs in SSR 2/1 were newly added. <Previous> Fire protection Reliability of power supply Function of other SSCs* Natural phenomena Seismic / Tsunami resistance DiD4 DiD3 <New> Response to intentional aircraft crash Suppression of radioactive materials dispersal Prevention of CV failure & large release Prevention of core damage (Postulate multiple failures) Internal flooding (New) Fire protection Reliability of power supply Function of other SSCs Natural phenomena (Volcano, Tornadoes, Forest fire: New) Seismic / Tsunami resistance (SA Measures) NEW Reinforced & New Reinforced 8

10 iii. Practical Elimination and Safety Goal 9

11 The New Requirements in Plant States Operational States Previous Design Requirements Accident Conditions NO AOO DBA DEC w/o Sig. Fuel Deg. (DEC-a) w/core Melt (DEC-b) a 4b New Design Requirements Operating Safety Program (~EOP~SAMG~) Practically Eliminated of Early/Large Release Non-P.E.: SFP, Catastrophic Disaster, Intentional Aircraft Crash B-DEC: Mobile equipment, e.g. Cannon Spray Pump DEC Mitigation Equip.: Classified in Higher Class SSR-2/1 (Rev. 1): No Significant Gaps 10

12 Safety Goal (Conceptual Scheme) Status CDF CFF-1 CFF-2 Core Damage Controlled Release Uncontrolled Release Freq Release 100 TBq (CS 137 ) Measures Prevent Core Damage Prevent CV Failure Prevent CV Damage & Large Release Mitigate Expansion Applied to all NPPs equally Safety Goal is the goal that NRA should achieve through implementing its regulation over nuclear facilities 11

13 iv. Review Guide for Severe Accident Measures 12

14 Outline of SA Measures Requirements 1. Outline of SA Measures Requirements General Requirements on the SA measures Equip. Preparation of procedures, implementation of drills, and development of organizational system Prepare equipment and procedures for the following 19 13

15 Prepare equipment and procedures Reactor shutdown Cooling reactor at high / low pressure Depressurizing RCPB Securing UHS Cooling, depressurization and RM reduction in the atm. CV Preventing the CV failure due to overpressurization Cooling molten core fallen to the bottom of the CV Hydrogen explosions inside the CV and R/B etc. Cooling, shielding and maintaining the sub-criticality of SFP Securing make-up water and water sources power sources Control room Emergency response center Instrumentation devices Radiation monitoring facilities Communications devices Suppression of off-site radioactive 14

16 AM for EE beyond DB & Evaluation 2. AM for External Events beyond Design Basis AM with mobile equipment, etc. 3. Evaluation of the Effectiveness of SA Measures Preventive measures against core damage and CV failure Prevent measures against fuel damage in SFPs Prevent measures against fuel damage in a reactor during shutdown 15

17 v. Continuous Improvement for Safety 16

18 Continuous Improvement of Regulatory Requirements and Systems 1. As-Built or As-Is plant description and compliance with requirements (Clarification of license basis ) 2. Voluntary Efforts for Safety Improvement: Policy and plan on continuous improvement of safety Feedback of operating experience and state-of-the-art knowledge/information, and plant walk-down Additional actions taken Peer Review (e.g. IAEA OSART) 3. Effectiveness of voluntary efforts demonstrated by: Level 1 and 2 PRAs for both internal / external events Safety margin analysis (e.g. stress test) 4. Comprehensive Assessment for Plant Safety 17

19 Continuous Improvement of Regulatory Requirements and Systems 1. Strengthen the OEF Process through Technical Information Committee Single-Phase Open Circuit (Byron-2, US, 1/2012), Amended a relevant regulatory guide. 2. Always be vigilant to the state-of-the-art knowledge / information and therefore, is enhancing its learning process through bilateral / multilateral international cooperative activities. 18

20 NRA s System for Global OEF The NRA Advisory Committees Secretariat of NRA: Collection and Analysis of OE and Regulatory Activities Screening and Tracking Communication with Licensees Technical Information Committee Actions: Information notice to Licensees New Regulations and Guides Amendments to Existing Rs & Gs Information Sources: OECD/NEA, IAEA IRS, FINAS, INES, OECD/NEA/CNRA WGOE, WGIP, IAEA IRS,.. IAEA CSS, INSAG, IEMs,.. OECD/NEA CSNI Public information: U.S.NRC s Bulletins, Generic Letters, Info. Notices Bilateral info. exchange Licensees 19

21 vi. Conclusions 20

22 Conclusions The New Safety Requirements have been enforced since July, 2013 taking into account L.L. from 1F Accidents and IAEA SSs, such as Introduced DiD with Independency among levels Practically Use of non-permanent equipment Back-fit rule Safety Margins by stress test Main Points are SAM for Conditions exceeding DiD level 4 Higher value of the DBE for DEC equipment Improve safety continuously 21

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