ML12136A563
| ML12136A563 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 05/07/2012 |
| From: | Ross W EnerSys |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML12136A563 (2) | |
Text
EnerSys P.O. Box 14145 Reading, PA 19612-4145 E ner,,
800-538-3627 x 1974 Fax 610-208-1971 email: bill.rosscenersys.com wr-Full S nwww.enersys.com William R. Ross Manager, Americas Quality Assurance May 7, 2012 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555-001 To Whom It May Concern, This letter will serve as a follow up to the interim report sent to the Commission by EnerSys on March 12, 2012. The ipterim report was issued in regards to a 2GN-23 battery manufactured by EnerSys and installed as part of Station Battery 2-2 at the Dominion Virginia Power, North Anna Station. Battery verification testing performed at North Anna indicated that although the battery was able to meet North Anna's 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> discharge requirements, cell #59 appeared to show reduced capacity. As a result, Dominion returned cells #59 and #60 to EnerSys. The cells were received at the EnerSys Corporate Laboratory under Return for Analysis (RFA) ENS-1 1204.
Subsequent to the March 12 th letter, analytical testing on the components of the returned cells was completed. The results indicated there were no material composition discrepancies or assembly process anomalies. The only issue seen in cell #59 was that a portion of the positive active material physically separated from the positive grid structure. Additionally, data recorded during the manufacturing process was reviewed with no issues or nonconformities noted.
A visit to the North Anna site was undertaken by EnerSys Engineering to review information from both Station 1 and Station 2. Battery verification testing at both stations showed all station batteries to have acceptable performance. A comparison of the testing performed by North Anna and the testing performed by EnerSys indicated that there was no further capacity degradation in cell #59. It is expected that the cells in the two station batteries will perform similarly.
North Anna has agreed to return several cells from Station Batteries 2-1 and 2-2 during their spring 2013 outage. These will be returned to EnerSys for confirmation of the investigation findings.
Based upon our further investigation we have concluded that no deviation per 1 OCFR21.21 exists. The positive active material separation was determined to be to a unique inconsistency in that plate curing lot.
Please contact me with requests for additional information, comments or questions.
- Regards, William Ross Cc: W. Hunsberger (Dominion), J. Lewis, S. McHugh (Dominion), J. Reber, S. Vechy, S.
Weik, R, Zuidema, QA files