ML12188A578
| ML12188A578 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 07/17/2012 |
| From: | Mahesh Chawla Plant Licensing Branch III |
| To: | Entergy Nuclear Operations |
| Chawla M | |
| References | |
| TAC ME8129 | |
| Download: ML12188A578 (3) | |
Text
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION
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July 17, 2012 Y",.-:
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~O Vice President, Operations Entergy Nuclear Operations, Inc.
Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043-9530
SUBJECT:
PALISADES NUCLEAR PLANT -
SUMMARY
OF CONFERENCE CALL REGARDING THE SPRING 2012 STEAM GENERATOR INSPECTIONS (TAC NO. ME8129)
Dear Sir or Madam:
By letter dated April 5, 2012 (Agencywide Documents and Management System (ADAMS)
Accession No. ML121000292), Entergy Nuclear Operations, Inc., the licensee for Palisades Nuclear Plant, submitted a notification of deviation from the Electric Power Research Institute (EPRI) Steam Generator Management Program: PWR [Pressurized Water Reactor] Steam Generator Examination Guidelines, Revision 7.
The deviation relates to the method used to size indications attributed to axially oriented outside diameter stress corrosion cracking. The deviation and the supporting justification were discussed with representatives of Palisades during conference calls on April 12 and April 20, 2012. Based on the information provided in the April 5, 2012, letter and the conference calls, the staff has the following comments concerning the deviation:
- 1. The April 5, 2012, letter does not appear to provide adequate justification for the deviation.
- 2. All data should be included in the sizing correlation unless it is excluded through application of objective data exclusion criteria (e.g., all Westinghouse data will be excluded). As a result, it may be acceptable to segregate the Combustion Engineering (CE) data from the total data set.
- 3. Statistical tests should be performed to justify that the CE data is statistically different than the total data set.
- 4. Even if the CE data set (I.e., the remaining data set after application of the data exclusion criteria) does not meet all the requirements of Appendix I of the PWR Steam Generator Examination Guidelines for sizing, it may be useful to develop a correlation to understand the uncertainties associated with the sizing method.
- 5. If the Westinghouse and CE data are from different statistical populations, assessment of the probability of detection for the data sets may be needed.
- 6. If there are not enough data points in the CE data set, a strategy for obtaining additional data could be developed which satisfies the industry guidelines for qualifying techniques.
Additional confidence in the sizing methods could be obtained from the removal of tubes for destructive examination.
- 7. Successful performance of in-situ pressure tests on indications larger than the in-situ pressure test screening criteria does not necessarily imply that the sizing methods are conservative since the screening criteria are intended to be conservative.
- 2 If you have any further questions or concerns, you can contact me at 301-415-8371 or Mahesh.chawla@nrc.gov.
Sincerely, Mahesh Chawla, Project Manager Plant Licensing Branch 111-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-255 cc: Distribution via ListServ
- 2 If you have any further questions or concerns, you can contact me at 301-415-8371 or Mahesh.chawla@nrc.gov.
Sincerely, IRAJ Mahesh Chawla, Project Manager Plant Licensing Branch 111-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-255 cc: Distribution via ListServ DISTRIBUTION:
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NAME MChawla BTully/Rohrer IfI GKulesa IFrankl DATE 7/12/12 7/12/12 7/13/12 7/17/12 OFFICIAL RECORD COpy