ML18094A895
| ML18094A895 | |
| Person / Time | |
|---|---|
| Issue date: | 03/14/2018 |
| From: | De Messieres C NRC/NRR/DRA/APLB |
| To: | |
| Moulton C | |
| References | |
| Download: ML18094A895 (14) | |
Text
Plans for Increasing NRC Staff Capabilities to Use Risk Information in Decision-Making Activities Candace de Messieres, PhD Reliability and Risk Analyst Risk Informed Licensing Initiatives, NRR, NRC
NRC Has a Longstanding Commitment to Increasing the Use of Risk Informed Decision-Making (RIDM)
PRA Implementation Plan, 1994 Risk-Informed Regulation Implementation Plan, 2000 Risk-Informed and Performance-Based Plan, 2006 - Present Risk Management Regulatory Framework, 2012 Current Approach 2
Significant Progress Has Been Made but Cultural, Process, and Technical Challenges Still Remain 1.
Staff members have varying degrees of awareness, knowledge, and support for RIDM processes and applications.
2.
The staff is working to more fully integrate reviews to include complementary insights from traditional engineering and risk assessment approaches.
3
Integrated Decisionmaking (RG 1.174)
- 2. Change is consistent with defense-in-depth (DiD) philosophy.
- 3. Maintain sufficient safety margins.
- 4. Proposed increases in CDF or risk are small and are consistent with the Commissions Safety Goal Policy Statement.
- 5. Use performance measurement strategies to monitor the change.
- 1. Change meets current regulations unless it is explicitly related to a requested exemption or rule change.
3.
Guidance for reviewing formal risk-informed submittals is well established.
Guidance for the use of risk insights in other types of licensing reviews could be enhanced.
Challenges Cont.
4
Internal Events Internal Flooding Internal Fire No 10%
No 7%
No 37%
Yes 90%
Yes 93%
Yes 63%
Seismic, High Winds, or External Flooding Are models across the fleet peer-reviewed?*
Yes 46%
No 54%
4.
Licensee probabilistic risk assessments (PRAs) have varying levels of maturity limiting generic applicability of risk-informed initiatives.
- Source: 2013 letter from NEI to NRC (ADAMS Accession No. ML13354B997) 5 Challenges Cont.
Level of PRA Acceptability Depends on the Application Risk-Informed Inservice Inspection 50.69 SSC Categorization 5b, Risk-Informed Surveillance Frequencies NFPA-805, Risk-Informed Fire Protection 4b, Risk-Informed Completion Times Acceptability Required scope, level of detail, technical elements, and plant representation Greater reliance on PRA More flexibility for licensee More complex staff review 6
4.
Licensee probabilistic risk assessments (PRAs) have varying levels of maturity limiting generic applicability of risk-informed initiatives.
Challenges Cont.
7 Challenges Cont.
5.
Unrealistic PRA modeling assumptions can mask or change high-risk contributors leading to over or underestimates of total risk thereby potentially affecting operational flexibility.
6.
Aggregated quantitative risk values can approach risk acceptance guidelines.
NRC Has a Cross-Cutting Approach to Overcome Challenges I.
Evaluate and Update Guidance II.
Develop a Graded Approach for Using Risk Information in Licensing Reviews III.
Enhance Mandatory Training Requirements Related to RIDM for Managers and Staff IV.
Advance Risk-Informed Initiatives V.
Enhance Communication on Risk-Informed Activities 8
Strategy Challenge Strategy I Evaluate and Update Guidance Strategy II Develop Graded Approach Strategy III Enhance Staff Training Strategy IV Advance Risk Initiatives Strategy V Increase Commun.
- 1. Knowledge and Support X
X X
- 2. Review Integration X
X X
X
- 3. Guidance Development X
X X
X
- 4. PRA Acceptability X
X
- 5. PRA Realism X
X X
- 6. Risk Aggregation X
X X
NRC Has a Cross-Cutting Approach to Overcome Challenges 9
A Living RIDM Action Plan Provides a Framework for Implementing Strategies Expand use of review teams with risk analysts and technical staff Broaden understanding of risk and risk insights Apply a graded approach for using risk information in licensing reviews Address RIDM related recommendations from an NRC differing professional opinion panel report Evaluate guidance Evaluate use of internal risk-informed tools Evaluate the use of LERF in various regulatory applications 10
Enhance the integration of risk information into the organizations decision making practices and processes to improve the technical basis for regulatory activities, increase efficiency, and improve effectiveness NRR RIDM Mission SECY Paper Strategies Strategy IV Advance Risk-Informed Initiatives Strategy III Enhance Mandatory Training Tasks PHASE 1 Evaluate tasks to generate findings and recommendations PHASE 2 Implement recommendations Strategy I Evaluate/Update Guidance Strategy II Develop Graded Approach Cross-Cutting Communication Strategy V Enhance Communication Action Plan Cont.
11
The NRC Maintains its Commitment to Increasing the Use of RIDM Staff recognizes the evolving cultural, process, and technical challenges associated with increasing the use of RIDM.
Staff has articulated a strategic vision for addressing challenges for the reactor program.
A living action plan has been developed and is enabling positive change towards increased use of RIDM.
12
References U.S. Nuclear Regulatory Commission, Policy Issue, SECY-17-0112, Plans for Increasing Staff Capabilities To Use Risk Information in Decision-Making Activities, (ADAMS Accession No. ML17270A197).
Action Plan: Risk-Informed Decision-Making - Operating Reactor Business Line (CAC No. A11008) (ADAMS Accession No. ML18005A911).
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Acronyms CDF: Core Damage Frequency LERF: Large Early Release Frequency DID: Defense-In-Depth F&O: Fact and Observation (Finding)
LAR: License Amendment Request NEI: Nuclear Energy Institute NFPA: National Fire Protection Association NRR: Office of Nuclear Reactor Regulation NTTF: Near Term Task Force PRA: Probabilistic Risk Assessment RG: Regulatory Guide RICT: Risk-Informed Completion Time RIDM: Risk-Informed Decision-Making RITS: Risk-Informed Technical Specifications SFCP: Surveillance Frequency Control Program SSC: Structure, System, or Component SR: Surveillance Requirement SRM: Staff Requirements Memorandum TS: Technical Specification TSTF: Technical Specification Task Force 14