ML21217A262
| ML21217A262 | |
| Person / Time | |
|---|---|
| Issue date: | 08/11/2021 |
| From: | NRC/NRR/DNRL |
| To: | |
| Hiser A | |
| Shared Package | |
| ML21217A247 | List: |
| References | |
| Download: ML21217A262 (5) | |
Text
Materials Programs Technical Information Exchange Public Meeting Update on High-Energy Line Break Activities Nuclear Regulatory Commission August 11, 2021 Virtual Meeting
Overview and Timeline 2015:
User Need Request May 2019:
TLR - BTP 3-4 Background and History ML19144A089 June 2019:
Public Meeting ML19214A095 Fall 2019 - Winter 2020:
NRC staff developed recommended option for alternative criteria January 2021:
New UNR that focuses on recommended option March 2021:
Public Meeting ML21089A005
Revising BTP 3-4: Underlying Philosophy Significantly revamp existing BTP o
Eliminate stress reduction criteria, relax CUF criterion o
Consider other degradation mechanisms o
Tailor fatigue evaluations, as needed, to applicable systems/components Support operating reactor, new reactor, and advanced reactor applications o
Provide identical framework and approach o
Require unique evaluations or analysis depending on reactor type Approach should be risk-informed o
Consider both susceptibility to degradation and failure consequences o
Utilize a graded approach consistent with the risk Broaden scope beyond classical, LWR welded-piping systems o
Include other types of connections (e.g., bolted) o Include other appropriate passive components/systems The approach will be similarly applicable for high and moderate-energy level breaks
Guidance Approach: Similar Philosophy to SRP 3.6.3 - Leak-Before-Break (LBB)
Break Preclusion Demonstration Address consequences of failure and susceptibility to applicable degradation mechanisms Screening Analyses Screening Perform analyses to demonstrate that the probability of piping failure is extremely low Analyses SRP 3.6.3 - LBB Determination Increasing Risk Increasing Rigor
Current Status and Path Forward
- NRC staff is developing the framework and associated technical basis
- Future deliverables:
o TLR on the technical basis for the alternative framework (mid 2022) o TLR that documents the alternative framework and associated technical basis (late 2022) o NUREG documenting the technical basis for the alternative framework (2023)