ML110760581

Slides- Audit of Salem'S Use of Westems Fatigue Software

ML110760581
Person / Time
Site:	Salem
Issue date:	03/11/2011
From:	On Yee Office of Nuclear Reactor Regulation
To:
Gettys E, NRR/DLR, 415-4029
References
Download: ML110760581 (6)

Text

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