05000219/FIN-2014005-02
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Finding | |
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| Title | Inadequate Review of Change in Maintenance Process Results in Inoperable Emergency Diesel Generator |
| Description | The inspectors identified a preliminary White finding and an associated apparent violation of 10 CFR 50, Appendix B, Criterion III, Design Control, because Exelon staff did not review the suitability of the application of a different maintenance process at Oyster Creek that was essential to a safety-related function of the emergency diesel generators (EDG). Specifically, in May 2005, Exelon staff changed the method for tensioning the cooling fan belt on the EDG from measuring belt deflection to belt frequency and did not verify the adequacy of the acceptance criteria stated for the new method. As a result, Exelon staff did not identify that the specified belt frequency imposed a stress above the fatigue endurance limit of the shaft material, making the EDG cooling fan shaft susceptible to fatigue and subsequent failure on July 28, 2014. As a consequence, Exelon also violated Technical Specification 3.7.C, because the EDG No. 2 was determined to be inoperable for greater than the technical specification allowed outage time. Exelons immediate corrective actions included entering the issue into their corrective action program as issue report (IR) 1686101, replacing the EDG No. 2 fan shaft, examining the EDG No.1 fan shaft for extent of condition, and performing a failure analysis to determine the causes of the broken shaft. This finding is more than minor because it is associated with the equipment performance attribute of the Mitigating Systems cornerstone and affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences (i.e., core damage). In accordance with IMC 0609.04, Initial Characterization of Findings, and Exhibit 2 of IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power, issued June 19, 2012, the inspectors screened the finding for safety significance and determined that a detailed risk evaluation was required because the finding represented an actual loss of function of a single train for greater than its technical specification allowed outage time. The detailed risk evaluation concluded that the increase in core damage frequency was 5.1E-6, or White (low to moderate safety significance). This finding does not have an associated cross-cutting aspect because the performance deficiency occurred in 2005 and is not reflective of present performance. |
| Site: | Oyster Creek |
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| Report | IR 05000219/2014005 Section 4OA2 |
| Date counted | Dec 31, 2014 (2014Q4) |
| Type: | Violation: White |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71152 |
| Inspectors (proximate) | A Patel B Dionne B Fuller E Burkett J Deboer J Kulp J Schoppy J Viera M Orr N Floyd P Kaufman R Deese S Kennedyb Bickettb Klukar G Carpenter H Nieh J Wray L Casey M Gray M Mclaughlin N Warnek R Lorson S Kennedy |
| Violation of: | 10 CFR 50 Appendix B Criterion III, Design Control Technical Specification |
| INPO aspect | |
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Finding - Oyster Creek - IR 05000219/2014005 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Oyster Creek) @ 2014Q4
Self-Identified List (Oyster Creek)
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