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Tsuyoshi Nakajima Regulatory Standards and Research Division Nuclear Regulation Authority (NRA-Japan)

Overview of Regulations and Guides in Japan

IAEA, Vienna, Austria 3-6 October 2016

Technical Meeting on Novel Design and Safety Principles of NPPs

Technical Meeting on Novel Design and Safety Principles of NPPs, Vienna, Austria, 3-6, October, 2016

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 Technical Meeting on Novel Design and Safety Principles of NPPs, Vienna, Austria, 3-6, October, 2016

i. Japan Update


Timeline and Current Status

The NRA was established in Sep. 2012 and urgently started developing the new regulatory requirements for NPPs which came into force in July 2013.

After the 1F accidents, all the 48 units had suspended their operation one by one by May 2012.

• 26 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. 2015

IRRS mission’s review was done in Jan. 2016


Nuclear Power Reactors in Japan

＜Tomari＞

＜Higashidori＞

＜Onagawa＞

＜Fukushima Dai-ichi＞

＜Fukushima Dai-ni＞

＜Tokai Plant, Tokai Dai-ni＞

＜Hamaoka＞

＜Ikata＞

＜Sendai ＞

＜Genkai ＞

＜Shimane ＞

＜Takahama＞

＜Ohi ＞

＜Kashiwazaki-Kariwa＞

＜Shika＞

＜Mihama＞

＜Tsuruga＞

Reactors undergoing decommissioning (3)

Already Service Terminated (6)

Specified nuclear facility

BWR (24)

PWR (24)

Restarted (3)

Applied (26)

＜Ohma＞ BWR, under Construction (2)

As of Oct, 2016

Application

PWR 16

BWR 10

Total 26

Application of Conformity Review for NPPs


Licensee Facility

JNFL Reprocessing /Uranium Enrichment /MOX Fuel Fab。/High-Level Radioactive Waste Storage Center

RFS Spent Fuel Storage Facility (Interim Storage)

JAEA Oarai R&D Center (Waste Management Facility)

MNF Uranium Fuel Fab. Facility (PWR)

NFI Uranium Fuel Fab. Facility (Tokai(BWR)/Kumatori(PWR))

GNF-Japan Uranium Fuel Fab. Facility (BWR)

Kyoto Univ. RRs (KUR/KUCA)

Kinki Univ. RR

JAEA RRs(JRR-3/NSRR), STACY , R&D facility

JAEA Oarai R&D Center, RRs (HTTR/JMTR)

Application of Conformity Review for FCFs and RRs


ii. Overview of the New Regulations


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


<Previous>

<New>

Re

info

rced

&

Ne

w

(SA M

easu

res)

NEW

R

ein

force

d

Req. for AOOs and DBAs were strengthened.

Req. for “SAs” that are equivalent to “DECs” in SSR 2/1 were newly added.

DiD4

Structure of New Regulatory Requirements


Seismic / Tsunami resistance

Natural phenomena

Reliability of power supply

Function of other SSCs*

Fire protection

Seismic / Tsunami resistance

Natural phenomena (Volcano, Tornadoes, Forest fire: New)

Prevention of core damage (Postulate multiple failures)

Suppression of radioactive materials dispersal

Response to intentional aircraft crash

Prevention of CV failure & large release

Function of other SSCs

Internal flooding (New)

Fire protection

Reliability of power supply DiD3

iii. Practical Elimination and Safety Goal


The New Requirements in Plant States

New Design Requirements

Previous Design Requirements

Operational States Accident Conditions Practically

Elimin

ated

o

f Early/Large

Re

lease

NO AOO DBA DEC

w/o Sig. Fuel Deg. （DEC-a)

w/Core Melt (DEC-b)

1 2 3 4a 4b

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

Operating Safety Program (～EOP～SAMG～)

Technical Meeting on Novel Design and Safety Principles of NPPs, Vienna, Austria, 3-6, October, 2016 10

Safety Goal (Conceptual Scheme)

CDF CFF-1 CFF-2

Status

Freq. 10-4 10-5 10-6

Release 100 TBq (CS137)

Measures Prevent Core

Damage Prevent CV Failure Prevent CV Damage

& Large Release Mitigate

Expansion

Core Damage Controlled Release Uncontrolled Release

Applied to all NPPs equally

Safety Goal is the goal that NRA should achieve through implementing its regulation over nuclear facilities

Technical Meeting on Novel Design and Safety Principles of NPPs, Vienna, Austria, 3-6, October, 2016 11

iv. Review Guide for Severe Accident Measures


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

Outline of SA Measures Requirements


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

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

AM for EE beyond DB & Evaluation


v. Continuous Improvement for Safety


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

Continuous Improvement of Regulatory Requirements and Systems


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.


Secretariat of NRA: • Collection and Analysis of OE and

Regulatory Activities • Screening” and Tracking” • Communication with Licensees

• Actions: “Information notice” to Licensees New Regulations and Guides Amendments to Existing Rs & Gs

NRA’s System for Global OEF

Advisory Committees

Technical Information Committee

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

The NRA

Licensees


vi. Conclusions


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


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