05000269/FIN-2011010-04
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Finding | |
|---|---|
| Title | Inadequate Control Circuit Voltage Calculations for 4160V breakers |
| Description | The team identified a Green non-cited violation (NCV) of 10 CFR Part 50, Appendix B, Criterion III, Design Control , for the licensees failure to perform adequate voltage calculations for safety-related 4160V circuit breaker 125VDC control circuits. The licensee entered these issues into their corrective action program as PIPs O-11- 11438, and performed evaluations to provide reasonable assurance that components would have adequate voltage pending formal re-analysis. The team determined that the failure to perform adequate design calculations for 125VDC control circuits was a performance deficiency (PD). The PD was more than minor because it affected the Mitigating Systems Cornerstone attribute of Design Control, and affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. In addition, the finding is similar to IMC 0612 Appendix E, example 3.j because the issue resulted in a condition where there was a reasonable doubt with respect to operability of safety-related components. Specifically, there was reasonable doubt as to whether the safety related circuit breakers would have adequate control voltage to perform their safety function during all required conditions. The finding was considered to be of very low safety significance since this was a design deficiency confirmed not to have resulted in a loss of operability or functionality. The team determined that no cross cutting aspect was applicable because this finding was not indicative of current licensee performance. |
| Site: | Oconee  |
|---|---|
| Report | IR 05000269/2011010 Section 1R21 |
| Date counted | Sep 30, 2011 (2011Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.21 |
| Inspectors (proximate) | B Desai G Skinner J Hamman L Mellen M Riley M Yeminy P Higgins T Lighty |
| INPO aspect | |
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Finding - Oconee - IR 05000269/2011010 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Oconee) @ 2011Q3
Self-Identified List (Oconee)
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