ML19074A142
| ML19074A142 | |
| Person / Time | |
|---|---|
| Issue date: | 03/19/2019 |
| From: | Don Helton, Tim Reed Special Projects and Process Branch, NRC/NRR/DRA |
| To: | |
| Venkataraman B | |
| References | |
| Download: ML19074A142 (8) | |
Text
Current Thoughts on Resolving Low Safety Significant IssuesOffice of Nuclear Reactor RegulationPublic MeetingMarch 19, 2019Tim Reed, Division of Operating Reactor LicensingDon Helton, Division of Risk Assessment Presentation PurposeProvide current thoughts on potential process enhancements and encourage feedback from stakeholders 2
Problem*In some cases, there is an inappropriate expenditure of resources and attention on low safety significant issues
- While this is the exception, not the rule, it appears to stem, in large measure, from the complexity, uniqueness, and lack of detail in the licensing basis 3
Nexus of Issues with the Licensing Basis
- The licensing basis (LB), while complex, challenging, and constantly changing, serves it purpose well
-but there are exceptions
- Issues arise where the information in the LB is subject to different interpretations
-e.g., "old" issues that date from the 60's, 70's, early 80's
- When an issue has a clear nexus to the LB it is addressed with the standard approaches (i.e., typically "fix it" or change the LB)
- When it does not have a clear nexus and it is not clearly in the LB then our current view is that we have discretion and flexibility on how to proceed
- One idea to address the "not in" situation: if, based on a complete LB record, the issue does not clearly fall within the LB, then pause and assess safety significance
- What about the scenario when the issue is "in" the LB and it is readilyapparent to be low safety significant?
4 High safetyLow safetyNot clearly within the existing licensing basisClearly within the existing licensing basisAddress issue with appropriate tools such as:
- Enforcement
- Order*Consider prompt corrective actions (CAP)Address issue with appropriate tools (i.e., either the licensee comes into compliance or changes the licensing basis):
- Corrective actions (CAP)
- Enforcement discretion
- Change the licensing basis (50.59, LAR, relief, exemptions, etc)*Assess adequacy of the requirement (i.e., rulemaking)Evaluate issue to determine regulatory actions with tools such as:
- 50.54(f) or generic communication
- Backfittting
- If generic
-screen as a generic issue
-EXIT:*Document decision
- Make public record 5
Thoughts on Low Safety Significance Determination
- The good news is that we have lots of ways of determining significance-unfortunately, we have lots of ways of determining significance-
- We should leverage elements of this existing guidance:
-e.g., PRA-distilled screening questions
-e.g., Office Instruction LIC
-504-e.g., Regulatory Guide 1.174
- Some challenges:
-Assessing safety margin and defense
-in-depth upstream of determining oversight vs. backfitstanding-Having sufficiently characterized the issue to reasonably judge safety significance
-Handling the nexus between individual plant
-specific issues,and emergent issues that apply to multiple plants 6
Need for Clear and Durable Documentation
- Document the issue and its impacts on SSCs, and human performance
- Document associated LB including if there were different perspectives between the licensee and NRC on the LB
- Document the conclusion: Not clearly in the LB
- Document the basis and conclusion that it is low safety significant
- Conclude no further regulatory action is needed and LB can remain "as is"
- Make the record a public record.
7 Thank You 8