05000315/FIN-2015003-06
Finding | |
|---|---|
| Title | Licensee-Identified Violation |
| Description | A finding of very low safety significance (Green) with an associated NCV of TS 5.4, Procedures, was identified by the licensee for the failure of th
1AB EDG during testing following a maintenance period. Shortly after the EDG was started, it automatically shut down on high bearing temperature Investigation revealed that the #4 main bearing had failed. The licensee performed a root cause analysis which determined that electric arcing ha occurred through the bearing which led to the failure. One of the contributors to the arcing was that air had been left in the lube oil system following maintenance. TS 5.4, Procedures, requires, in part, that the applicable procedures recommended in Regulatory Guide 1.33, Revision 2, Appendix A, February 1978 be established, implemented, and maintained. Section 9 of Regulatory Guide 1.33 states, in part, that maintenance that can affect the performance of safety-related equipment should be properly preplanned and performed in accordance with written procedures, documented instructions, or drawings appropriate to the circumstances. Contrary to this requirement, the procedures for performing maintenance on the lube oil system allowed air to remain in the lube oil system, which helped facilitate electric arcing in the 1AB EDG bearings. The issue was more than minor because it adversely affected the equipment performance attribute of the Mitigating Systems cornerstone, with the objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. The finding screened a Green based on answering no to the Mitigating Systems screening questions in IMC 0609 Appendix A, The Significance Determination Process for Findings at Power, effective July 1, 2012. The issue was entered into the CAP as AR-2015-6917. The inspectors concluded the issue was licensee-identified based on the guidance in IMC 0612, Power Reactor Inspection Reports, issue date January 24, 2013. Under the definition of licensee-identified findings, IMC 0612 states that most, but not all, licensee-identified findings or violations are discovered through a licensee program or process. One of the processes listed is post-maintenance testing, which was how the bearing failure was discovered. |
| Site: | Cook  |
|---|---|
| Report | IR 05000315/2015003 Section 4OA7 |
| Date counted | Sep 30, 2015 (2015Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | Licensee-identified |
| Inspection Procedure: | |
| Inspectors (proximate) | J Ellegood J Lennartz J Mancuso K Riemer M Garza M Learn R Edwards R Elliott T Taylor |
| Violation of: | Technical Specification - Procedures Technical Specification |
| CCA | H.9, Training |
| INPO aspect | CL.4 |
| ' | |
Finding - Cook - IR 05000315/2015003 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Cook) @ 2015Q3
Self-Identified List (Cook)
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