Recent Changes of Safety Regulation in Korea

Transcription

1 IAEA TM on Novel Design and Safety Principles, 3-6 Oct Recent Changes of Safety Regulation in Korea Kyun-Tae Kim TFT for SA Regulation KINS

2 Contents 1. History of Regulation on Severe Accident TMI Action Items in 1980s and 1990s to Severe Accident Policy in 2000s Responses to Fukushima Accident 2. References of Rulemaking Existing Practice and International Trend Vienna Declaration on Nuclear Safety 3. Amendment of Nuclear Safety Act Subsequent rulemaking Concepts, DiD, Safety Target Scheme of APM 4. Concluding Remarks 2

3 1.1 History of Regulation on Severe Accident TMI(1979) Chernobyl(1986) Fukushima(2011) s * SA : Severe Accident; * SAP : Severe Accident Policy 3

4 1.2 Responses to Fukushima Accident Fukushima Accident (2011) Regulatory authority performed special inspection after Fukushima accident and issued 50 post-fukushima Action Items (2011) Post-Fukushima Action Items are for Enhancing capabilities against natural hazard; Improving safety functions and accident management capabilities; and Improving emergency preparedness and emergency medical system. New regulatory authority (Nuclear Safety and Security Commission; NSSC) was established (2011) Stress Test for the old NPPs : Wolsong-1, Kori-1 4

5 2.1 References of Rulemaking Trend Previous regulations on severe accident were reviewed Regulations under administrative orders based on Severe Accident Policy Regulations under administrative orders after Fukushima accident Recent international efforts to reflect the lessons learned from Fukushima accident is reviewed IAEA s new safety series (SSR-2/1, TECDOC ) and TECDOC US NRC s rulemaking (Fukushima orders, 10 CFR , ) Japan NRA s new safety standards (2013) Canadian REGDOC Design of Reactor Facilities (2014) European countries safety rule EU Council Directive 2014/87 to amend 2009/71 ( ) WENRA RSHG safety objectives ASN resolution 2012-DC-0283 ( ) & 2014-DC-0406 ( ) Vienna Declaration on Nuclear Safety ( ) 5

6 2.2 References of Rulemaking - VDNS Vienna Declaration on Nuclear Safety ( ) 1. New nuclear power plants are to be designed, sited, and constructed, consistent with the objective of preventing accidents in the commissioning and operation and, should an accident occur, mitigating possible releases of radionuclides causing long-term off site contamination and avoiding early radioactive releases or radioactive releases large enough to require long-term protective measures and actions. 2. Comprehensive and systematic safety assessments are to be carried out periodically and regularly for existing installations throughout their lifetime in order to identify safety improvements that are oriented to meet the above objective. Reasonably practicable or achievable safety improvements are to be implemented in a timely manner. 3. National requirements and regulations. 6

7 3.0 Amendment of Nuclear Safety Act in 2015 Background of the Amendment of Nuclear Safety Act Previous regulation was on the basis of administrative orders. National Assembly (parliament) amended the Nuclear Safety Act to clearly stipulate the regulatory control on severe accident in legal basis. Accident Management Plan requirement Amended NSA requires submission of Accident Management Plan(AMP) (including severe accident management) at the time OL application for new units and within 3 years for existing units Accident Management : A set of actions to prevent the escalation of accidents, to mitigate the consequence of accidents and to recover a nuclear power plant from accident conditions The effective date of the amendment is 23 July, 2016 AMP will cover all levels of accidents (DBA, SA prevention & mitigation) and explain management measures to cope with each of accident levels. 7

8 3.1 Amendment of Decree and Regulations Subsequent rulemaking is done To support the amendment of NSA, subsequent rulemaking (amendment of presidential decree, prime ministry s decree and other rules) is under way and will be completed before the effective date of the amendment of NSA. To reflect international trends and domestic requests. Major elements of the rulemaking are; Rules on the contents and acceptance criteria for AMP, including safety goal, accident management strategies, procedures and guidelines to address accidents, licensee s staffing, education and training. Rules on design features and mitigation strategy to prevent and mitigate severe accidents resulting from multiple failures of safety systems as well as from extreme natural or man-made hazards Rules on assessment of environmental impact from severe accidents 8

9 3.2 Concepts of AMP Role and Contents of AMP AMP is a document to explain the capability of NPP to cope with design basis accident, to prevent severe accident, and to mitigate severe accident based on; Safety goal of NPP SAR, PSA, and RER Operating procedures and guides SAR DBA, BDBE ESF, Other Equipment PSA Results RER Radiological Impact on Environment Realistic Approach EOG/ /SAMG Procedures and Guides Response Measures Integration Strategy Accident Management Plan Safety Goal Selection of Events Counter Measures to Events 9

10 3.2 Defense-in-Depth in AM Basic Concept for Accident Management Definition of Accident Management by Nuclear Safety Act A set of actions to prevent the accidents, to mitigate the consequence of accidents and to recover a nuclear power plant from accident conditions Adoption of IAEA s Defense in Depth (DiD) Concept Level Plant State (Accident Condition) Management Measures Design Basis Accident (3a) Single failure of Safety System Design Basis Event (Seismic, Flood, ) Engineered safety features Emergency procedures Prevention of Severe Accident (3b) Multiple failure of Safety System Extreme natural/man-made hazards SA prevention features SA prevention guidelines (3) recovery Mitigation of Severe Accident (4) Core melt-down SA mitigation features SA mitigation guidelines (1) Prevention of escalation (2) Mitigation of consequence AMP will cover all levels of accidents and explain management measures to cope with each of accident levels. 10

11 3.3 Amendment of Decree and Regulations Decree of NSA To include AMP related measures in the inspection (Article 35) Enforcement Regulation of NSA Contents of AMP at the time of OL Application (Article 16.4) scope of the accident management, equipments used for accident management, accident management strategies and implementation systems, evaluation of accident management capabilities (including PSA), development of emergency operating procedures, management plan for severe accidents, training for accident management, and other matters required by the Commission for accident management. Periodic Safety Review (Article 20) To include AMP in the scope of evaluation 11

12 3.3 Amendment of Decree and Regulations Regulation on Technical Criteria of Nuclear Installations Section 6 is created to define the criteria for AM (Article 85.19) DBA, Multiple Failure, External Event, and Severe Accident shall be included in the scope of AMP (Article 85.20) Equipment required for AM shall be able to perform the required functions in the accident conditions. (Article 85.21) AM Strategy and Implementation system (Article 85.22) Safety objectives and Assessment Avoid large release to cause health effects and long-term contamination Extremely low increase in risk to the public and environment Deterministic and Probabilistic Safety assessment to be performed whether the safety objectives are met. (Article 85.23) Education and Training of AMP 12

13 3.3 Amendment of Decree and Regulations Safety Target in Commission Notice Site Boundary Exposure Dose < 250mSv Environment Cs TBq < 10-6 Health Objective Risk< 0.1% of Total Risk, or CDF<10-5 & LERF<

14 3.4 Assessment of AMP Accident Category Conditions to be Considered Goal No Significant Fuel Damage Core Damage DBA Prevention of SA Multiple Failure External Event Mitigation of SA Major Threats Anticipated Transient With Scram Station Black Out Multiple SGTR Total Loss of Feedwater Flow Inter-system Loss of Coolant Accident Loss of Shut-Down Cooling Loss of Ultimate Heat Sink Loss of SI or Recirculation with SBLOCA Loss of Cooling in Spent Fuel Storage Additional condition identified by PSA Natural event beyond design basis Intentional aircraft crash (that is not able to predict the likelihood of occurrence) Conditions induced by the condition 1 & 2 Combustion or explosion of combustible gas High temp. or overpressure in containment Molten core concrete interaction High pressure melt ejection Direct containment heating Fuel-coolant interaction Containment Bypass including TI SGTR Additional condition identified by PSA Fuel Cooling & CV Integrity CV Integrity Exposure Dose : 250mSv at Site Boundary Risk Increase less than 0.1% of Total Risk Cs-137 > 100 TBq Release Freq. < 10-6 /yr Equipment, Procedure, Guidance, and etc) 14

15 [Ref.] IAEA TECDOC-1791 (Safety Demonstration) 15

16 4. Concluding Remarks Harmonization with International Trend Reflection of Vienna Declaration on Nuclear Safety Establishment of reasonable safety goal and standards by benchmarking international standards Amendment of Regulation under Nuclear Safety Act Amendment of regulation by the enforcement date of June 23, 2016 Regulatory guidance is to be examined : Exposure dose calculation Dedicated measures including movable equipment Consideration of domestic status Considering the level of safety from the point of view of public acceptance Voluntary and proactive efforts of operators are needed 16

17 Thank you for your attention KINS