International Atomic Energy Agency

Implementation of a Risk-Informed Approach into the Legislative and Regulatory Framework

SNRCU Annual Topical Meeting Kiev, Ukraine December 2008

John F. Preston, IAEA

Risk-Informed Decision Making (RIDM) - A Way of Thinking

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We have a need – a decision is required, a judgement to be made We apply a process – we consider, weigh, integrate complex inputs & insights

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Deterministic Safety Assessment

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Probabilistic Safety Assessment

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Operational Experience Compensating or Mitigating Measures Other Pertinent Considerations We consider We assess each input & its context with each other & with whole Δ s or Conformance to Guidance We make a judgement based on: Safe, Sound, Optimum Decisions We record feedback) the decision and process so that if further information becomes available – we can re-assess the validity of the judgement. (i.e. it is a fundamentally dynamic process sensitive to

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Risk Assessment

Defense in Depth Regulatory Compliance Safety Margins Performance Monitoring • Deterministic Considerations • Risk

↓ →,

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Benefits of Risk-Informed Decision Making

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Improved Safety:

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Risk insights have revealed and led to the correction of installation vulnerabilities. Correction (provisions for prevention or mitigation) has been through installation changes; improved programs, processes, and procedures; and enhanced awareness, operations, maintenance, and other activities.

Increased Reliability:

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Risk insights provide guidance to adjust surveillance and inspection scope and frequency. This balance increases overall system and component availability while adequately verifying operability.

Increased Operational Flexibility:

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Having risk insights and understanding the change of risk with changing installation configuration can allow a more balanced and dynamic application of the licensed safe operating envelope; e.g., technical specifications.

Reduced Radiological Exposure:

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Focusing maintenance on more risk-significant areas reduces unnecessary activities in high radiation areas. Applications such as risk-informed in-service inspection have provided significant radiological exposure reductions.

Increased installation performance and cost effectiveness of operations:

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A comprehensive and balanced understanding of an installation’s risk spectrum allows limited resources to be applied to the more risk-significant aspects while conserving resources applied to less risk-significant aspects.

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How to achieve the benefits of RIDM

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To gain the benefits that RIDM can provide, changes are required at the legislative and regulatory level as well as at the plant operational level At the legislative and regulatory level, a legal basis for RIDM must be provided which includes safety goals, guidance and appropriate regulation Change should be gradual The ‘good news’ is that in many cases the existing legislative and regulatory procedures are already sufficient to allow RIDM – and if change is needed, often these can be very small (e.g. ‘should’ to ‘shall’)

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Implementation Infrastructure

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Legal Basis

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Policy

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Safety Goals Regulation RIDM Upper Tier Guidance

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Programs & Procedures

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DSA, PSA, Monitors Scope, Quality, Control, Maintenance Support: Data, Insights, References, Other Information Reporting & Communication Trending, Feedback, Adjustment Training & Qualification Applications With all these the IAEA can assist – a TECDOC is in preparation

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RIDM TECDOC RIDM Perspective, Principles, Limitations, Cautions RIDM Programme Structure Infrastructure: Legislation Safety Goals Regulatory Framework Guidance Licensing Interfaces Programmes Procedures Communication Reporting Tool Control & Maintenance: DSA PSA Monitors Hardware Assessment: RIDM-IR Support: Data References Insights Staff Organizational Culture Applications: Procedures Decision Guidance Development: Training Workshops

IAEA Assistance

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RIDM TECDOC

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RIDM Implementation Program & Infrastructure

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Centre for Advanced Safety Assessment Tools (CASAT)

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Data, Insights, References, & Other Information

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RIDM International Review (RIDM-IR)

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Capacity Development

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Pilot Studies, Workshops, Fellowships, etc

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Дякую - Спасибо

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Pilots

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Hungary HAEA & Paks NPP

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Armenia

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Other Expressed Interest Note: Parallel WWER Regulators Forum Activities Support Pilot States

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RIDM Development

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NPP Common Design Harmonization Groups

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Experience Indicates Leaders

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Assess & Resolve Spectrum of Common Issues Examples of Such Groups

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PWR Owners Group PWR Owners Group, PSA Sub-Committee

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Source: Significant RIDM Progress in U.S.

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WWER Regulators Forum WWER Regulators Forum PSA Working Group

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Potential Source: Significant RIDM Progress Internationally

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Superb Forum for Both Regulators & Operators

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The Regulatory Benefits of RIDM

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RIDM can help enhance:

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Regulation Development Licensing Inspection Planning Significance Determination Events Assessment Emerging Issues

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Education Needed

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Culture Change

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Gradual

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Needs Progressive Cultivation

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Benefits of RIDM & PSA

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Recognized in Many Arenas

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Other Arenas Starting to Recognize

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Other Arenas Appear to Need Assistance

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How to achieve the benefits of RIDM (con’t)

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The regulators must check that at the legislative and regulatory level that:

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The specified safety goals encompass a RIDM approach?

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The safety goals are quantitative?

That risk is factored into the licensing for plants in the member state?

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Does the set of legal requirements establish the means to perform activities or the goals to be achieved?

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The safety goals are reflected in RIDM related applications?

The regulators must specify and/or check the RIDM processes to ensure they have confidence in the conclusions With all these the IAEA can assist – a TECDOC is in preparation

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The international nuclear community (designers, suppliers, constructors, licensees, operators, support organizations, and regulators) increasingly recognizes and emphasizes that probabilistic safety assessment (PSA) and other risk evaluations provide extremely valuable complementary insight, perspective, comprehension, and balance to deterministic safety assessment of nuclear installations. Accordingly, there is an immediate need to establish international standards for RIDM.

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Applications

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Configuration Management

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Configuration Risk Analyzer (CRA)

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Technical Specifications Maintenance & Outage Planning, Assessment, & Management Regulatory

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Regulation Development Licensing Inspection Planning Significance Determination Events Assessment Emerging Issues

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NPPs

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Plant Vulnerabilities Design & Design Review Plant Improvement Program Improvement In-Service Inspection In-Service Testing Quality Assurance Special Treatment Security Emergency Response Training Non-NPP Emerging Applications

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How to achieve the benefits of RIDM (con’t)

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The regulators must specify and/or check the RIDM processes to ensure they have confidence in the conclusions:

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As with any decision making, RIDM is not an exact science; it requires thoughtful and balanced consideration of a spectrum of inputs

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Mathematical models, deterministic and probabilistic, can assess only what is modeled. Such models cannot address out of scope phenomena

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There are uncertainties; such uncertainties relate to phenomenological understanding, model completeness, data, assumptions, boundary conditions, equipment performance, and human performance.

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PSA Working Group Intended Direction

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Support RIDM Implementation in WWERs Assimilate, Coordinate, Disseminate:

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Data Insights References Related Information & Lessons Learned Establish & Support Harmonization

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Organizational Culture Fundamental RIDM Principles Terms & Definitions Data Format Establish & Support Fluent Communication

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