Application of the Concept of Graded Approach in Core Regulatory Functions:Risk-Informed Decision Making (RIDM)

Executive Director of OperationsU.S. Nuclear Regulatory Commission

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Key Messages

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• The USNRC has a rich history of incorporating risk insights to support regulatory decisions.

• We believe that matters that have low or little safety significance divert NRC staff and licensee resources away from significant safety issues.

• Incorporating risk insights into decision-making regarding licensing and oversight activities improves safety and enhances efficiency.

• We continue to invest in infrastructure, capacity, and methods to address technical and cultural challenges associated with Risk-Informed Decision Making (RIDM).

USNRC Risk-Informed Approaches Support a Graded Approach

Regulations and Guidance• Rulemaking• Guidance Development• Generic Communications• Standards Development

Oversight• Inspection• Performance Assessment• Enforcement• Allegations• Investigations

Support for Decisions• Research Activities• Advisory Activities• Adjudication

Licensing and Certification• Licensing• Certification

Operational Experience• Emergency Response• Events Assessment• Generic Issues

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Risk-Informed Approach*

A "risk-informed" approach to regulatory decision-making represents a philosophy whereby risk insights are considered together with other factors to establish requirements that better focus licensee and regulatory attention on design and operational issues commensurate with their importance to health and safety.

* NRC STAFF REQUIREMENTS - SECY-98-144 - White Paper On Risk-informed And Performance-based Regulationhttps://www.nrc.gov/reading-rm/doc-collections/commission/srm/1998/1998-144srm.pdf

https://www.nrc.gov/reading-rm/doc-collections/commission/srm/1998/1998-144srm.pdf

Integrated Decision Making (RG 1.174)

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Performance-Measurement

Strategies Used to Monitor Change

Acceptably Small

Increases in risk (if any)

Meets Current

Regulations

Consistent with

Defense-in-Depth Philosophy

Maintains Sufficient

Safety Margins

PresenterPresentation Notes

Evolution of Risk-Informed, Performance-Based Regulation

WASH-1400 (1975)

Severe Accident Policy Statement (1985) & Safety Goal Policy (1986)

PRA Policy (1995).

SRM-SECY-98-144: White Paper on Risk-Informed Performance-Based Regulation

ROP SECY-99-007A: Recommendations for ROP Improvements

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Graded Approach in Inspection Activities

Inspection(IMC 0609)

• The USNRC Reactor Oversight Process uses a graded approach to NPP declining performance

• A process is used to risk-inform the significance and enforcement response

• Changes in risk levels informs regulatory decisions on resources to conduct additional inspection

PresenterPresentation Notes

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Refinements to a Mature Reactor Oversight Process

• Better focus USNRC and industry resources on issues of higher safety significance

• In line with USNRC’s desire to be a more modern and risk-informed regulator

• https://www.nrc.gov/reactors/operating/oversight/rop-enhancement.html

https://www.nrc.gov/reactors/operating/oversight/rop-enhancement.html

Licensing Activities:improvements in safety focus

IPEs\IPEEEs (1989-early

1990) (Mandatory request for

information)

Maintenance Rule

(Mandatory Rule)

Risk-Informed Inservice

Inspection

NFPA-805, Risk-Informed Fire Protection (Voluntary rule adopted by ~

50% units)

Surveillance Frequency

Control Program

(voluntary initiative

adopted by ~ 90% units)

10 CFR 50.69 SSC

Categorization (voluntary initiative;

majority of plants intend

to adopt)

Risk-Informed Completion

Times (voluntary initiative;

majority of units plan to

adopt

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~ 75%

~ 25% ~ 1%

~ 99%

How Regulations Allow Licensees to Adopt a Graded Approach Using Safety Significance

• 50.69 allows adjusting the treatment of SSCs based on its safety classification

• Rule consists of three major elements– Categorization

Process– Alternate

Treatment – Feedback and

Process Adjustments10

USNRC Addressing Challenges by Advancing Risk-Informed Decision Making

• Evaluate/Update guidance• Develop graded licensing approach• Enhance mandatory training• Advance risk-informed licensing initiatives• Enhance communication

Operating Reactor RIDM Action Plan

strategies

Key Outcomes• Use of Integrated Review Teams• Sustainable guidance and expectations• Communicating with stakeholders

Action Plan completed

December 30, 2018 with additional

recommendations and actions

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• Enhanced Safety Focused Review Approach− Developed for small modular reactors− Includes tools and strategies to help

formulate scope and depth of review

• Licensing Modernization Project− Technology-inclusive, risk-informed,

and performance-based guidance for licensing non-LWRs - enabling a graded approach

RIDM Applied in New Reactor Licensing

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• New Reactor Reviews− Regulations require description of PRA and

results− Risk information used to meet Commission

objectives

The USNRC is Committed to Modernize Our Decision-Making

• USNRC goal is to increase use of risk insights to decide and guide the quality and level of effort appropriate for a given activity.

• We have articulated a strategic vision for addressing RIDM challenges and created a sustainable approach for the reactor program.

• In 2018, the USNRC Transformation Initiative recognized the importance of scaling the scope and level of depth of licensing reviews according to risk and safety insights.

• Work remains to improve graded approach to safety reviews in licensing activities for operating and new nuclear plants.

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PresenterPresentation Notes

Slide Number 1Slide Number 2USNRC Risk-Informed Approaches Support a Graded ApproachRisk-Informed Approach*Integrated Decision Making (RG 1.174)Evolution of Risk-Informed, �Performance-Based RegulationGraded Approach in Inspection ActivitiesRefinements to a Mature �Reactor Oversight Process�Licensing Activities:�improvements in safety focusHow Regulations Allow Licensees to Adopt a Graded Approach Using Safety SignificanceUSNRC Addressing Challenges by Advancing Risk-Informed Decision Making�Slide Number 12The USNRC is Committed to Modernize �Our Decision-Making�