05000445/FIN-2011006-03
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Failure to Follow Operability Determination Process for Degraded Safety Related Diesel Generators |
| Description | The team identified a Green noncited violation of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, for the failure of the licensee to follow the operability determination Procedure ODA-309, Operability Determination and Functionality Assessment Program. Specifically, the licensee did not appropriately evaluate a long-standing degraded condition such that the diesel generators would remain operable for their mission time as required by Procedure ODA-309. As a result, adequate compensatory measures were not established to ensure operability. The licensee entered the finding into the corrective action program as Condition Report CR 2011-008508. The performance deficiency was determined to be more than minor because it was associated with the equipment performance attribute of the Mitigating System Cornerstone and affects the cornerstone objective to ensure the availability and reliability of safety related diesel generators that respond to initiating events to prevent undesirable consequences in that the safety related diesel generators supply power to safety related loads. Because Manual Chapter 0609, Attachment 4, Phase 1 - Initial Screening and Characterization of Findings, was not well suited for this finding, a Phase 3 Risk Significance Estimation was required. A Region IV senior reactor analyst performed a bounding Phase 3 significance determination and determined that the finding was of very low safety significance. The bounding change to core damage frequency was 6.7E-7/year. The simplified plant analysis risk (SPAR) model does not include the contribution of the recently installed alternate power generators, which would lower the risk significance of a safety related diesel generator failure for the station blackout sequences, which comprise most of the risk of this finding. The team determined that there was a crosscutting aspect in the area of human performance decision-making because the licensee failed to use conservative assumptions in decision making in the assessment of operability. |
| Site: | Comanche Peak  |
|---|---|
| Report | IR 05000445/2011006 Section 4OA2 |
| Date counted | Sep 30, 2011 (2011Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71152 |
| Inspectors (proximate) | J Reynoso W Sifre J Kramer J Braisted D Powers |
| CCA | H.14, Conservative Bias |
| INPO aspect | DM.2 |
| ' | |
Finding - Comanche Peak - IR 05000445/2011006 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Comanche Peak) @ 2011Q3
Self-Identified List (Comanche Peak)
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||