05000313/FIN-2014002-01
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Finding | |
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| Title | Failure to Maintain Alternate ac Diesel Generator Governor |
| Description | The inspectors reviewed a self-revealing non-cited violation of 10 CFR 50.63, Loss of all alternating current power, for the licensees failure to maintain the alternate ac diesel generator as a power source available to withstand and recover from a station blackout. Specifically, the licensee failed to perform preventive maintenance on the governors of the diesel in accordance with the recommended vendor maintenance, which resulted in an overspeed trip of the engine during testing. The licensee repaired the governors and documented the issue in Condition Report CR-ANO-C-2013-00331. The inspectors determined that the failure to perform preventive maintenance on the governor of the alternate ac diesel generator in accordance with the recommended vendor maintenance was a performance deficiency. This performance deficiency was more than minor because it was associated with the equipment performance attribute of the mitigating systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences, and was therefore a finding. Specifically, the reliability of the alternate ac diesel generator was adversely affected by the lack of governor maintenance so that the diesel was unavailable to respond to a postulated station blackout. Using Manual Chapter 0609, Attachment 4, Initial Characterization of Findings, Appendix A, The Significance Determination Process (SDP) for Findings at Power, Exhibit 2, MitigatingSystem Screening Questions, the inspectors determined that the finding required a detailedrisk evaluation because it was an actual loss of function of a non-technical specification trainof equipment designated as high safety-significant in accordance with the licenseesmaintenance rule program for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The Region IV senior reactor analyst performed a detailed risk evaluation in accordance with Appendix A, Section 6.0, Detailed Risk Evaluation. The risk was dominated by internal loss of offsite power initiators and fireinduced loss of offsite power scenarios. The calculated change in core damage frequency was 8.9E-7 for Unit 1 and 5.6E-7 for Unit 2. The analyst also determined that the finding would not involve a significant increase in the risk of a large, early release of radiation. This finding has been determined to be of very low safety significance (Green). The finding was determined to have a cross-cutting aspect in the area of human performance, associated with consistent process, for the licensees failure to use a consistent and systematic approach that incorporated risk insights to make decisions. The inspectors determined that the cause of the performance deficiency was that the licensee failed to use a consistent process that incorporated risk insights to evaluate and implement preventative maintenance on the alternate ac diesel generator governor. Although the performance deficiency initially occurred over three years ago, the licensee documented in Condition Report CR-ANO-C-2014-00166 that the alternate ac diesel generator was not maintained commensurate with its risk significance and that a contributing cause was that management had not implemented a comprehensive maintenance strategy in accordance with the risk significance of the diesel. Therefore, inspectors concluded that the cause of the performance deficiency was reflective of present performance. Specifically, the licensee failed to implement a comprehensive preventative maintenance strategy on the alternate ac diesel generator governor commensurate with its risk significance [H.13] |
| Site: | Arkansas Nuclear  |
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| Report | IR 05000313/2014002 Section 1R22 |
| Date counted | Mar 31, 2014 (2014Q1) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71111.22 |
| Inspectors (proximate) | A Fairbanks B Tindell C Alldredge G Werner J Melfi L Carson M Young |
| Violation of: | 10 CFR 50.63 |
| CCA | H.13, Consistent Process |
| INPO aspect | DM.1 |
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Finding - Arkansas Nuclear - IR 05000313/2014002 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Arkansas Nuclear) @ 2014Q1
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