05000387/FIN-2011005-01
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Finding | |
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| Title | Failure to Properly Implement Work Instructions Results in C EDG Inoperability |
| Description | An NRC-identified Green finding of TS 5.4.1, Procedures, due to PPLs failure to properly plan and implement work instructions and Quality Control (QC) hold point inspections associated with a modification to the C Emergency Diesel Generator (EDG) fuel pump assemblies was identified. The error resulted in the failure of the C EDG to continue running during surveillance testing on December 6, 2011. This resulted in PPL failing to meet the requirements of TS 3.8.1, AC Sources- Operating , when it was determined that the C EDG was inoperable from September 19, 2011, following restoration from its maintenance outage, until December 6, 2011, when the operable E EDG was substituted for the C EDG. Additionally, the failure to implement work instructions resulted in PPL failing to meet the requirements of 10 CFR Part 50, Appendix B, Criterion X, Inspection, which requires, in part, that licensees execute a program for inspection of activities affecting quality to verify conformance with the documented instructions, procedures, and drawings for accomplishing the activity. The deficiency was entered into PPLs corrective action program (CAP) as condition Report (CR) 1506105 and a root cause analysis (RCA) was performed. The performance deficiency was determined to be more than minor because the finding was associated with the Mitigating Systems cornerstone attribute of Human Performance, and affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences (i.e., core damage). The finding was evaluated using Phase 1 and inspectors determined the finding was potentially greater than very low safety significance because the finding represented an actual loss of safety function of a single train for greater than its TS Allowed Outage Time. The Phase 2 analysis determined the finding was potentially greater than very low safety significance given an exposure time of 75 days. A Phase 3 analysis was conducted by an NRC Senior Reactor Analyst (SRA). This analysis indicated an increase in core damage frequency (ACDF) for internal initiating events in the range of 1 core damage accident in 40,000,000 years of reactor operation, in the low E-8 range per year for each unit. The dominant core damage sequences included losses of offsite power with the failure of all EDGs, due to common cause, resulting in a station blackout, followed by operator failure to extend RCIC operation with loss of DC power, failure to depressurize the reactor and failure to recover offsite power within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The finding is related to the CCA of Human Performance, Work Practices, in that PPL personnel did not use human error prevention techniques, such as holding pre-job briefings, self and peer checking, and proper documentation of activities, commensurate with the risk of the assigned task, such that work activities are performed safely. Specifically, PPL did not perform adequate human error prevention techniques such that the incorrect assembly of delivery valve springs and stops avoided. |
| Site: | Susquehanna  |
|---|---|
| Report | IR 05000387/2011005 Section 1R13 |
| Date counted | Dec 31, 2011 (2011Q4) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.13 |
| Inspectors (proximate) | F Arner J Caruso J Greives P Finney P Kaufman P Krohn R Edwards R Rolph S Hammann S Ibarrolaa Rosebrookc Crisden D Schroeder E Miller J Furia J Greives J Noggle K Modes P Finney P Krohn R Fuhrmeister S Ibarrola T Fish W Schmidt |
| CCA | H.12, Avoid Complacency |
| INPO aspect | QA.4 |
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Finding - Susquehanna - IR 05000387/2011005 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Susquehanna) @ 2011Q4
Self-Identified List (Susquehanna)
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