ENS 42678
ENS Event | |
|---|---|
05:00 Jun 30, 2006 | |
| Title | Part 21 - Defective Paperless Data Acquisation Recorders |
| Event Description | On May 3, 2006, Progress Energy (CP&L) Brunswick Nuclear Plant notified Thermo Electron that, during preventive maintenance on a Safety Related CSVC recorder, the rechargeable backup battery was found to have separated. Progress Energy also indicated that a similar failure had been found on a Non-Safety Related recorder prior to this incident. Neither recorder had failed while in service. Both are believed to have been in service approximately six (6) years with the original backup batteries installed.
Progress Energy requested that Thermo Electron evaluate the failures to determine a recommended course of action and determine whether or not a Part 21 Notification was appropriate. Thermo Electron organized an engineering team to immediately begin an investigation of the failures. Thermo engineers solicited the services of the battery manufacturer in their investigation. The backup battery installed on the CSVC is a NiCad sealed package. As the batteries age, the potential exists whereby if the batteries were fully discharged, which could occur during an outage or a shut down condition, a reverse charging situation may occur when the recorders are brought back on-line. If a reverse charging condition occur, the byproduct is hydrogen gas which could be sufficient to cause the battery to split open. This is not a normal condition, but could occur in batteries that have been in service for a number of years. There is no apparent hazardous condition within the recorder as a result of this failure and the recorder would continue to function properly while under power. There have been no failures reported in any nuclear safety-related application of CSVC recorders while in operating mode. Should the battery fail, it will not cause the recorder to present or record any erroneous data. However, should a recorder lose power after such a battery failure has occurred, the system configuration would be lost. Corrective Action : Thermo Electron has determined that a recommended replacement interval for the rechargeable battery should be documented to prevent the potential for this condition to occur in the future. The battery packs as originally installed on the CSVC are no longer available. A replacement has been identified which has been tested and verified to be suitable for the backup battery application. This replacement does not compromise the original qualifications of the CSVC recorder. The battery pack (Thermo Part Number 1063-0200-001, Revision A) should be available for purchase within thirty (30) days. Thermo Electron recommends that utilities with CSVC recorders that have been in service greater than three (3) years with original batteries installed consider replacing the batteries at the next maintenance interval. The recommended replacement cycle for the replacement battery pack shall be three (3) years from the date the recorder is placed in service or the battery was replaced. Utilities have the option of purchasing batteries for replacement at their facility or returning the CSVC recorders to Thermo Electron for battery replacement. Customers may contact Thermo Electron for spare parts or to request return for service.
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| Where | |
|---|---|
| Thermo Electron Corporation Sugar Land, Texas (NRC Region 4) | |
| Organization: | Thermo Electron Corporation |
| Reporting | |
| 10 CFR 21.21 | |
| Time - Person (Reporting Time:+17.22 h0.718 days <br />0.102 weeks <br />0.0236 months <br />) | |
| Opened: | Barry Nicholson 22:13 Jun 30, 2006 |
| NRC Officer: | John Knoke |
| Last Updated: | Jul 3, 2006 |
| 42678 - NRC Website | |
Thermo Electron Corporation with 10 CFR 21.21 | |
WEEKMONTHYEARENS 426782006-06-30T05:00:00030 June 2006 05:00:00
[Table view]10 CFR 21.21 Part 21 - Defective Paperless Data Acquisation Recorders 2006-06-30T05:00:00 | |