ML12091A055
| ML12091A055 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 03/11/2011 |
| From: | On Yee Office of Nuclear Reactor Regulation |
| To: | Atomic Safety and Licensing Board Panel |
| SECY RAS | |
| Shared Package | |
| ML12091A053 | List: |
| References | |
| RAS 22178, 50-247-LR, 50-286-LR, ASLBP 07-858-03-LR-BD01 | |
| Download: ML12091A055 (6) | |
Text
NRC000119 Submitted: March 31, 2012 Audit of Salems use of WESTEMS Fatigue Software On Yee March 11, 2011
Identified Issues in New Reactors
- Two issues associated with WESTEMS performing NB-3600 calculations:
- the use of the algebraic summation of three orthogonal vectors
- methodology for stress combination related to thermal stresses t
- Configuration control in WESTEMS - the ability of users to modify intermediate data (peak and valley stresses/times) used in the analyses 2
Impact to License Renewal
- Salem Nuclear Generating Station
- RAI 4.3-07 issued November 22, 2010
- Requested applicant to perform benchmark calculations for two locations (pressurizer surge nozzle and 1.5 BIT safety injection nozzle)
- Discuss applicability of identified issues 3
Impact to License Renewal
- Audit Objectives
- Review benchmark calculations to ensure WESTEMS provides results comparable to traditional NB-3200 analysis
- Address the acceptability of analyst intervention in modifying intermediate WESTEMS data
- Address the role of the WESTEMS NB-3600 module in license renewal calculations 4
Audit Observations
- January 18-19, 2011
- Documentation of analyst intervention was not available
- Applicant verbally justified analyst intervention for the BIT nozzle
- Confirmed that WESTEMS calculations that support the Salem LRA did not use the NB-3600 module
- Confirmed C fi d th thatt WESTEMS provides id resultslt th thatt are reasonable bl andd consistent with a traditional ASME Code Section III, NB-3200 analysis for the two locations
- Applicant agreed to revise calculations to document results, for both locations, with and without analyst intervention
- February 8, 2011
- Revised calculations for both locations documented the results with and without analyst intervention
- Justifications for analyst intervention needs to be sufficiently specific 5
Results from Audit
- Use of a software package to perform fatigue calculations should be consistent with ASME Code,Section III
- Analyst intervention should be justified and documented when using a software package to perform fatigue calculations
- WESTEMS NB-3600 module should not be used until identified issues are resolved
- The staff has reasonable assurance that Salems use of the WESTEMS NB-3200 Design CUF module provides results that are consistent with a traditional ASME Code,Section III NB-3200 analysis
- Options are currently being considered on how to generically communicate the concerns and results of the audit 6