ENS 47735
ENS Event | |
|---|---|
04:00 Mar 12, 2012 | |
| Title | Interim Report Concerning Battery Cells with Potentially Reduced Discharge Capacity |
| Event Description | This letter will serve as the interim report to the Commission as pursuant to 10CFR21.21 (a) (2). The notification is 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-11204.
During our analysis, which consisted of float charging, discharge testing at the 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rate and an internal inspection it was determined that the cell was unable to meet the defined technical requirements for discharge capacity. Following the determination a series of analytical tests were ordered to perform more in depth analyses of the internal components. Testing on the component samples is currently underway. At this time we have not yet been able to determine if a "defect" as defined in Part 21 exists and therefore this interim report has been prepared. It is expected that the current tests will be completed by May 11, 2012. However, it should be noted that further analysis including the return of additional cells may be required to determine the cause and the reportability under Part 21 reporting. Throughout the return and analysis processes EnerSys has been in contact with representatives of the North Anna Station. They have been made aware of the electrical test results and recently of the internal inspection results. They are also aware that there has been no cause determination at this time. Station personnel have also been notified that this interim report has been issued.
The following information was received from EnerSys via fax: Subsequent to the March 12th 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. Based upon our further investigation we have concluded that no deviation per 10CFR21.21 exists. The positive active material separation was determined to be to a unique inconsistency in that plate curing lot. Notified R2DO (Freeman) and NRR Part 21 Group via email. |
| Where | |
|---|---|
| Enersys Reading, Pennsylvania (NRC Region 1) | |
| Organization: | Enersys |
| Reporting | |
| 10 CFR 21.21(a)(2), Interim Report for Comply or Defect in Component | |
| Time - Person (Reporting Time:+11.55 h0.481 days <br />0.0687 weeks <br />0.0158 months <br />) | |
| Opened: | William Ross 15:33 Mar 12, 2012 |
| NRC Officer: | Pete Snyder |
| Last Updated: | May 11, 2012 |
| 47735 - NRC Website | |
Enersys with 10 CFR 21.21(a)(2), Interim Report for Comply or Defect in Component | |
WEEKMONTHYEARENS 522162016-09-01T04:00:0001 September 2016 04:00:00
[Table view]10 CFR 21.21(a)(2), Interim Report for Comply or Defect in Component Part 21 - Potential Failure of Battery System Connections ENS 477352012-03-12T04:00:00012 March 2012 04:00:00 10 CFR 21.21(a)(2), Interim Report for Comply or Defect in Component Interim Report Concerning Battery Cells with Potentially Reduced Discharge Capacity 2016-09-01T04:00:00 | |