05000244/FIN-2014005-05
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Finding | |
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| Title | A' Emergency Diesel Generator Output Breaker Fails to Close during Routine Surveillance Testing Resulting in a Condition Prohibited by Technical Specifications and a Potential Inability to Fulfill a Safety Function |
| Description | On September 10, 2014, during performance of a routine scheduled surveillance test, STP-O-12.1, Emergency Diesel Generator A, Revision 01600, the output supply breaker to safeguards bus 14 failed to close on demand. Initial troubleshooting revealed no obvious issues with the breaker, and the output supply breaker functioned as required during a second test. A spare breaker was installed and tested satisfactorily on Enclosure 22 September 11, and the A EDG was restored to operable. Exelon concluded that the A EDG had been inoperable since the last successful performance of STP-O-12.1 on August 13, 2014. This 29 day period exceeded the TS allowable outage time of 7 days. Exelons subsequent troubleshooting revealed no electrical issues with the circuit breaker, and the failure modes and effects analysis concluded that the most likely cause of the circuit breaker failing to close was the breaker did not properly reset after performance of the surveillance test on August 13, 2014. The breaker could not be verified to be reset without an internal inspection. The original equipment manufacturer was also requested by Exelon to investigate the cause of the breaker failure. The original equipment manufacturer concluded that the lack of free movement of the operating mechanism trip shaft was the cause of the breaker not resetting and closing. The trip shaft did not move freely due to lack of end-to-end play. Exelons apparent cause evaluation associated with this issue and AR 02178745 noted that these circuit breakers undergo full PM every 4 years, and all PMs on both EDG output breakers have been done in accordance with the PM frequency. The last performance of the PM for the bus 14 breaker was on November 14, 2011. The procedure for the PM has the technicians check for free movement of the trip of the trip shaft, but not end-to-end play movement or clearances to allow end-to-end play. Additionally, the vendor manual does not direct measuring clearances or verifying end-to-end play; this is called out as a vendor task. Therefore, the inspectors concluded that no performance deficiency existed since it was not reasonable for Exelon to foresee and prevent this issue. The inspectors reviewed LER 2014-003-00 and determined that traditional enforcement applies in accordance with IMC 0612, Sections 0612-09 and 0612-13, and NRC Enforcement Policy, Section 2.2.4.d, because a violation of NRC requirements existed without an associated Reactor Oversight Process performance deficiency. The inspectors determined that the maintenance completed on the bus breaker was in accordance with vendor recommendations. This issue was considered to be a Severity Level IV violation of TS 3.8.1 in accordance with Enforcement Policy Section 6.1.d. In addition, IMC 0612, Appendix B, Figures 1 and 2, Issue Screening, were referenced in documenting this Severity Level IV self-revealing violation. This issue was entered into Exelons CAP as AR 02178745. Because it was not reasonable for Exelon to have been able to foresee and prevent the breaker failure, the NRC determined no performance deficiency existed. Thus, the NRC has decided to exercise enforcement discretion in accordance with Section 3.5 of the NRC Enforcement Policy and refrain from issuing enforcement action for the violation (EA-15- 004). Further, because Exelons action and/or inaction did not contribute to this violation, it will not be considered in the assessment process or the NRCs action matrix. This LER is closed. |
| Site: | Ginna  |
|---|---|
| Report | IR 05000244/2014005 Section 4OA3 |
| Date counted | Dec 31, 2014 (2014Q4) |
| Type: | Violation: Severity level Enforcement Discretion |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | A Rosebrook D Dodson D Schroeder E Andrews K Kolaczyk K Mangan N Perry S Horvitz T Fish T Hedigan |
| Violation of: | Technical Specification - Procedures Technical Specification |
| INPO aspect | |
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Finding - Ginna - IR 05000244/2014005 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Ginna) @ 2014Q4
Self-Identified List (Ginna)
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