ML23150A030
| ML23150A030 | |
| Person / Time | |
|---|---|
| Issue date: | 05/17/2023 |
| From: | Kenneth Hamburger, Reinaldo Rodriguez NRC/NRR/DRA |
| To: | |
| Hamburger K | |
| Shared Package | |
| ML23150A023 | List: |
| References | |
| Download: ML23150A030 (9) | |
Text
LIC-504 Reinaldo Rodriguez Reliability and Risk Analyst Division of Risk Assessment Assessment Office of Nuclear Reactor Regulation US NRC Public Meeting on Risk Insights Associated with HEAF 1
Background - Integrated Decision-Making Process for Emergent Issues (LIC-504)
- Developed as a lessons learned from Davis-Besse reactor vessel head degradation
- Provides a structured process and expectations to document decisions for issues that may warrant safety orders
- Provides guidance to apply integrated decisionmaking including risk, defense-in-depth, and safety margins considerations
- Has been used frequently for a range of emergent plant-specific and generic issues
- Not a substitute for other NRC processes 2 Public Meeting on Risk Insights Associated with HEAF
LIC-504 Graded Recommendations - Examples Weigh a Spectrum of Regulatory Options 10-3 Immediate regulatory action - compensatory measures Formal backfit analysis ( 10-4 )
10-4 50.54(f) letters Change in CDF Bulletin 10-5 Information Notice/Outreach Smart inspection samples -
within baseline program 10-6 No Actions Use RIDM -
10-7 Not numbers alone Regulatory Intensity 3 Public Meeting on Risk Insights Associated with HEAF
HEAF LIC-504 STEP 1 - NO IMMEDIATE SAFETY CONCERN STEP 2 - DETAILED EVALUATION USING DRAFT METHODOLOGY Public Meeting on Risk Insights Associated with HEAF 4
Scope Copper and aluminum HEAF zones The LIC-504 assessment was then of influence should be treated the focused on examining the change same based on the current state of in estimated HEAF risks associated knowledge. with the use of the new HEAF PRA methodology.
Public Meeting on Risk Insights Associated with HEAF 5
Visited one BWR and one PWR plant Assistance provided by each reference plant licensee was essential and added credibility and realism to the team's analyses Work Completed The team generated risk-informed insights and recommendations Publicly available memo with WG recommendations was issued on July 22, 2022 (ADAMS Accession No. ML22201A000).
Public Meeting on Risk Insights Associated with HEAF 6
THE RISK OF HEAF COULD BE HIGHER OR HEAF LIC-504 -
LOWER THAN CALCULATED UNDER THE PREVIOUS METHODOLOGY RISK COULD VARY SIGNIFICANTLY BASED ON PLANT CONFIGURATION Staff Insights FOR CERTAIN CONFIGURATIONS, THE ESTIMATED RISK FROM NON-ISO-PHASE BUS DUCTS COULD BE NOTABLY HIGHER THAN PREVIOUSLY MODELED CONCLUDED THERE IS NO SIGNIFICANT INCREASE IN TOTAL HEAF RISK, THAT WARRANTED THE NEED FOR ANY ADDITIONAL REGULATORY REQUIREMENTS Public Meeting on Risk Insights Associated with HEAF 7
Issue Information Notice Risk insights into NRRs ongoing PRA Incorporate configuration control initiative.
Recommendations Integrating risk insights into NRRs Consider inspection program in accordance with ROPs change control processes.
Risk insights with internal and external Communicate stakeholders.
Public Meeting on Risk Insights Associated with HEAF 8
Q&As and Comments Public Meeting on Risk Insights Associated with HEAF