05000352/FIN-2011003-01
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Finding | |
|---|---|
| Title | Failure to Position Recirculation lsolation Valves in Accordance with Clearance |
| Description | A Green, self-revealing NCV of Technical Specification (TS) 6.8.1, Procedures and Programs, was identified for failure to position the Unit 2 recirculation loop isolation valves in accordance with the clearance instruction. As a result, the decay heat removal 1ow path, as provided by Unit 2 \'A\' residual heat removal (RHR), was in a degraded condition from April 6,2011 until April 1 2,2011, when the valve mispositioning was corrected. In addition, if the RHR system had been aligned to the Shutdown Cooling mode with the valves mispositioned in the open position, a large portion of the cooling flow would have bypassed the core, significantly impacting decay heat removal capability. Exelon entered the issue into the Corrective Action Program (CAP) for resolution. The inspectors determined that the failure to position the Unit 2 \'A\' loop recirculation pump suction and discharge valves to the closed positions in accordance with a clearance is a performance deficiency. This issue is more than minor because it was associated with the Configuration Control attribute of the Initiating Events cornerstone (i.e., shutdown equipment lineup), and it affected the cornerstone objective of limiting the likelihood of those events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. This finding was determined to be of very tow safety significance (Green) using IMC 0609, significance Determination Process, Appendix G, Shutdown Operations Significance Determination Process, because the finding did not require quantitative assessment (i.e., the finding did not degrade the ability to recover decay heat removal once lost). Exelon entered this issue into the CAP for resolution. Corrective actions included remediating the reactor operator who applied the main control room tag and revising the cross check program to require a concurrent verification check on clearance applications for valves being de-energized with main control room indicators. The inspectors determined that this issue has a cross-cutting aspect in the area of Human Performance, Work Practices, because Exelon did not properly use human error prevention techniques (e.g., self and peer checking), commensurate with the risk of the assigned task. |
| Site: | Limerick  |
|---|---|
| Report | IR 05000352/2011003 Section 1R20 |
| Date counted | Jun 30, 2011 (2011Q2) |
| Type: | NCV: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71111.2 |
| Inspectors (proximate) | E Dipaolo T Moslak S Barr N Sieller P Krohn E Burket |
| CCA | H.12, Avoid Complacency |
| INPO aspect | QA.4 |
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Finding - Limerick - IR 05000352/2011003 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Limerick) @ 2011Q2
Self-Identified List (Limerick)
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