Use of Risk Information for Improving the Safety of Nuclear Power Generation

Transcription

1 Reference material 1 Nuclear Risk Research Center Symposium 2018 Use of Risk Information for Improving the Safety of Nuclear Power Generation February 8, 2018 The Federation of Electric Power Companies of Japan

2 Operation restart status of nuclear power stations 1 The industry s effort to comply with the New Regulatory Requirements is still halfway through, with just 5 plants having managed to resume operation. Situations remain tough in terms of both power supply demand and business revenue expenditure. Nuclear power generation is an important source of electricity in Japan. On the premise of safety assurance, we will work on the restart of plant operations and improvement in plants capacity factor after operation restart so as to achieve S+3E, thereby contributing to the Japanese economy. Sendai ➊➋ Tomari ➊➋➌ Kashiwazaki Kariwa ➊➋➌➍➎➏➐ Shika ➊➋ Oma Tsuruga 1➋ Mihama 12➌ Oi 12➌➍ Takahama ➊➋➌➍ Shimane 1➋➌ Genkai 1➋➌➍ Ikata 1➋➌ Higashidori (Tohoku) ➊ Onagawa ➊➋➌ Fukushima Daiichi Fukushima Daini ➊➋➌➍ Tokai Daini Hamaoka 12➌➍➎ PWR BWR Higashidori (Tokyo) ➊ Approval obtained Application filed Decommissioning Compliance approval status Approved ( ) Application filed ( ) Application not filed PWR ( ) BWR ( ) Total Total Status of decommissioning units 12 2 The above data includes 3 plants under construction. 14 PWR BWR Total Decommissioning ( )

3 Basic approach to the initiatives for safety improvement 2 Reflecting upon lessons learned from the accident at the Fukushima Daiichi Nuclear Power Station, the industry has worked on building a mechanism for tackling nuclear plants risks and reinforcing countermeasures for external events of significant impact, e.g. mega earthquake and tsunami, so as to improve the safety of nuclear power plants. 1 Multiple safety measures Multiple protection Safety-first plant operation, maintenance and management Nuclear safety risks 2 Reinforced hardware measures Design-basis measures Severe accident measures 4 Remaining risks Unflagging efforts toward safety 3 Reinforced frontline response capability Reinforced response structure Thorough employee training and education Hardware and software approaches to safety improvement Licensees initiatives Identifying important-to-safety matters and implementing effective countermeasures Actively utilize new insight (facilities, administration, etc.). Maintain and improve technological capacities (for operation, maintenance, etc.) at power stations. Maintain and improve emergencyresponse capabilities. Implement safety-improvement measures based on risk information from PRA, etc. (in collaboration with the NRRC). Handle risks based on the results of peer reviews (in collaboration with WANO, JANSI, etc.). and other initiatives it is important to work on the notion that you could never completely eliminate risks, and adopt Risk Management, in which nuclear licensees assume primary responsibility in implementing voluntary actions for safety improvement, expansion of emergency preparedness measures and appropriate risk management and reduction.

4 Strategic plan for using risk information --- To-Be state of nuclear business administration 3 In order to continuously manage power station risks, it is necessary to utilize risk information to identify areas that need reinforcement in plant equipment and administration, and implement effective measures in a timely fashion. The Strategic Plan for RIDM Introduction has been compiled to introduce decision-making based on risk information (Risk-Informed Decision-Making: RIDM) to plant management. Self-regulated management system for safety improvement (1) Performance, monitoring and evaluation (3) Decision -making (2) Risk assessment (4) Corrective Action Program (CAP) (5) Configuration management Technological foundation Process Human resources Note) Corrective Action Program (CAP): A mechanism for identifying and resolving issues at nuclear licensees, encompassing processes from assessing the issues relevance to safety, defining priority order for response and managing the progress through to full resolution. Note) Configuration management: Initiative for maintaining consistence in three elements, i.e. design requirements, physical facility configuration and facility configuration information

5 To-Be state of nuclear business administration 4 Issues concerning the management system with RIDM (1) Performance monitoring and evaluation Operation, maintenance and management capabilities for system performance monitoring, equipment reliability diagnostic technology, etc. Organizational and individual performance improvement program (2) Risk assessment Plant-specific PRA that eliminates serviceability as much as possible (3) Decision-making and implementation Management that can choose and carry out total optimization solutions taking into consideration uncertainty associated with risk assessment (4) CAP Process of ensuring to collect data on irregular statuses at low threshold from all workers Screening process in line with risk importance (5) Configuration management Sufficient ability to manage plant design so that it is not left entirely to manufacturers System for controlling facility configuration management information For all the functions, it is important to develop technological foundation / processes and foster human resources. Importance of leadership, organizational safety culture and organization-wide initiatives Accurately understand plant performance, and enhance the technological and organizational capability for identifying issues. Everyone involved in plant safety must use a common set of risk-based assessment criteria to correctly identify issues, make swift decision-making in the order of priority based on comprehensive knowledge and implement improvement measures. Use PRA to quantify risks, and build positive relationship with society and regulatory authorities, using risks as the common language.

6 Example of governance structure (Chubu Electric Power Company) 5 Hamaoka Nuclear Safety Advisory Board Internal and external experts Report President Chubu Electric Power Group Nuclear Safety Charter Nuclear Safety Improvement Board Report Opinion Advisory Board External experts On-site check Instruction Internal audit department Internal audit Report of audit results Report Instruction Chairman: President Members: Vice President General Manager of Nuclear Power Division General Manager of G Management Strategy Division Directors in charge of other departments Report Collaboration Instruction Company-wide risk management Board of Directors Reporting of important risks G Management Strategy Division Individual departments Risk communication Nuclear Power Division Checking and evaluating the status of risk reduction initiatives Risk information, response measures Opinions of people in society Communication Promotion Group Initiatives for internal and external communication Coordination Information Opinion Dialog activities Nuclear Risk Research Center WANO, JANSI, etc. Preparedness for nuclear risks Use of third-party reviews by voluntary regulatory organization People in local communities and the rest of society In light of the results of risk analysis and assessment, it is important for management to make decisions based on integrated judgment so as to implement necessary safety measures.

7 Example of risk communication (Chubu Electric Power Company) 6 Carry out active dialog activities to foster mutual understanding with the people of local communities. residents. Explain risks rather than appealing safety. Opinion exchange sessions Plan and organize opinion exchange sessions with local community associations, women s organizations, etc., and participate in opinion exchange sessions organized by local governments. Informal forums for women Under themes of strong interest among women (e.g. aromatherapy, yoga), provide energy-related information to initiate exchange of opinions. Door-to-door dialog Make door-to-door house calls in Omaezaki City, where a nuclear power station is located, as well as its surrounding three cities. Information caravan Set up a booth outside shopping centers and other places that attracts people, so as to initiate dialogs. Opinion exchange session Informal forum for women Plant tour Plant tour for the residents of Omaezaki City and 11 surrounding municipalities who apply It is important to use risk information for providing the overall picture of nuclear plants risks and risk reduction activities (accidents impact and probability, multi-layered accident prevention measures, accident mitigation measures, etc.) in plain language.

8 Initiatives for advancing the level of risk assessment 7 The NRRC has been set up within the CRIEPI to centrally undertake R&D on the mechanism of natural external events that do not occur very frequently but could deal substantial damage, the method of evaluating such events and advancement of PRA. Research examples at the NRRC Internal fires: Advancing PRA through the compilation of PRA guide, international research, testing, etc. Internal flooding: Compiling PRA guide, developing flooding simulation tools, etc. Tsunami: Using the Hamaoka Unit 4 as a model for developing tsunami PRA, and advancing PRA through assessment Severe accidents: Expanding knowledge on the progression of accidents and the integrity of PCV, etc. Other external events: Establishing a risk assessment method for tornadoes and volcanoes 3D fluid analysis on the behaviors of tsunami running up to a power station Impact force assessment of tsunami debris Incorporate the findings of research (external hazard, fragility, human reliability, equipment reliability, etc.) to licensees risk assessment as they become available to faithfully identify plant behaviors and reduce the uncertainty of risk assessment. Identify uncertainty and plant vulnerability as accurately as possible to make integrated judgment and decisions for enhancing plant safety and resilience. 2016

9 Summary 8 To achieve plant operation, it is important to ensure that licensees safety improvement initiatives are carried out autonomously and continuously. Licensees must assume primary responsibility in pursuing safety improvement and enhancement of emergency preparedness measures, and managing risks appropriately (risk management). Quantification of risks through probabilistic risk assessment (PRA) is important for risk management. Introduce risk-informed decision-making (RIDM) as an essential process. Licensees capabilities must be increased as the premise of RIDM introduction. Under strong leadership, licensees must promote necessary initiatives to attain the To-Be status of nuclear business administration. Promote R&D, continue making efforts to advance risk assessment technology and actively utilize advanced risk assessment to enhance plant safety and resilience. Through self-regulated initiatives for plant management, enhance plant performance to improve plants safety and capacity factor so as to achieve S+3E, thereby contributing to the Japanese economy.

10 (Reference) Excerpt from Strategic Plan and Action Plan for Utilizing Risk Information, a presentation material used in the Nuclear Risk Research Center Symposium 2018 (February 8, 2018) Strategic Plan for RIDM Introduction Phase 1 (up to 2020 or until the restart of plant operation) Advancing self-regulated plant management, using risk information Draw up specific initiatives and compile them into an action plan. Phase 2 (from 2020 or after the restart of plant operation) Continuously improving self-regulated plant management, and expanding the scope of RIDM use Expand the scope of RIDM use for day-to-day plant operation, maintenance and management Enhance necessary functions, such as PRA, to expand their scope of application to the mechanism of safety improvement management, incorporating RIDM, similar to in-service maintenance in the United States in the future. Phase 1 Phase 2 RIDM introduction and implementation Utilizing risk information with existing tools Developing necessary functions Implementing and utilizing RIDM in response to regulatory inspections Expanding functions in line with the introduction of RIDM Incorporating the results of R&D on external events into PRA