05000293/FIN-2015003-02
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Finding | |
|---|---|
| Title | Inadequate EDG Common Cause Determinations Result in TS Violation |
| Description | The inspectors identified a Green NCV of TS 3.5.F, Minimum Low Pressure Cooling and Diesel Generator Availability, for failure to adequately perform TS surveillance requirement (SR) 4.5.F.1 to determine that the B emergency diesel generator (EDG) was not inoperable due to a common cause failure, or to perform the TS-specified EDG monthly surveillance test, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the time that operators determined that the A EDG was inoperable. Specifically, on July 1, 2015, after the A EDG was declared inoperable due to unexpected annunciator response during engine pre-start checks, and again on July 28, 2015, when the A EDG was declared inoperable due to reactive load oscillations during a routine surveillance, Entergy performed an inadequate common cause failure determination that did not address the failure mechanism of the inoperable EDG, which had not yet been determined. This issue has been entered into the corrective action program as CR 2015- 8073, and additional guidance has been provided to the operations crew in the form of an operations section standing order, pending permanent corrective actions. The finding was more than minor because it was 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. Specifically, the operability of the B EDG was not verified as required, either through determination that it was not inoperable due to a common cause failure or through performance of the monthly TS-required surveillance. 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, the inspectors determined that this finding was of very low safety significance (Green) because the performance deficiency was not a design or qualification deficiency, did not involve an actual loss of safety function, and did not represent an actual loss of function of a single train for greater than its TS allowed outage time. This finding had a cross-cutting aspect in the area of Human Performance, Conservative Bias, because Entergy did not use decision making practices that emphasized prudent choices over those that are simply allowed, or in this case those choices that were perceived to be allowed. Specifically, Entergys credited SR 4.5.F.1 based on an administrative review instead of more deliberate actions or evaluations that would be necessary to confirm that a common cause condition did not exist. |
| Site: | Pilgrim |
|---|---|
| Report | IR 05000293/2015003 Section 1R15 |
| Date counted | Sep 30, 2015 (2015Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | B Dionne B Scrabeck E Carfang K Mangan R Mckinley J Dunn J Pfingstein |
| Violation of: | Technical Specification Technical Specification - Procedures |
| CCA | H.14, Conservative Bias |
| INPO aspect | DM.2 |
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Finding - Pilgrim - IR 05000293/2015003 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Pilgrim) @ 2015Q3
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