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| Entered date | Event description | |
|---|---|---|
| ENS 52216 | 1 September 2016 14:51:00 | This letter will serve as notification from EnerSys to the United States Nuclear Regulatory Commission of an identified deviation in published literature information. The literature defines requirements for resistance in both cell to cell and cell to terminal connections in supplied battery systems. High connection resistance causes increased cell voltage drop and a potential failure to meet run time requirements. Internal investigation by EnerSys confirms that no defects exist in systems tested before shipment to customer utilities as internal documented procedures define correct parameters. However, the potential of less than desired performance exists if the values noted in the literature are used during installation and test at utility sites. EnerSys does not have the ability to evaluate if a defect exists at customer utilities so per the provisions of Part 21, notification is being made to both the Commission and affected EnerSys customers. POC: 800-538-3627 ext. 1974
The literature in question is the EnerSys Safety, Storage, Installation, Operation and Maintenance Manual for Flooded Lead-Acid Batteries C, D, E, F and G, number US-FL-IOM-002 dated January 2007. The errors are located in Section 7.4.3.8c line 2. The current wording of '... connection is more than 30 percent or 5 Mohms above the average...' should read 'connection is more than 10 percent or 5 micro-ohms, whichever is greater, above the average'. Licensees affected are Dominion North Anna, Dominion Surry Nuclear Power Plant, Energy Northwest Columbia Generating Station, Entergy Nuclear Operations IP2, First Energy Beaver Valley NPP, NextEra Energy Point Beach Nuclear Plant, Perry Nuclear Power Plant, and San Onofre Nuclear Generating Station. Notified R1DO(Powell), R2DO (Bartley), R3DO (Dickson), R4DO (Warnick), and Part 21Group via email. |
| ENS 47735 | 12 March 2012 15:33:00 | 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 hour 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 hour 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. |