05000528/FIN-2013005-03
From kanterella
Jump to navigation
Jump to search
Finding | |
---|---|
Title | Licensee-Identified Violation |
Description | Title 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, requires, in part, that activities affecting quality be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and be accomplished in accordance with these instructions, procedures, or drawings. Contrary to the above, prior to October 26, 2012, the licensee failed to have an adequate test procedure to perform safety injection check valve testing. Specifically, the licensee identified that latent test procedure deficiencies allowed a cold leg safety injection header manual drain valve common to both emergency core cooling system (ECCS) trains to be open without an evaluation that ECCS flow requirements would be satisfied. The licensee identified that deficiencies in previous revisions of surveillance test (ST) procedure 73ST-9SI05, Leak Test of HPSI/LPSI Containment Isolation Check Valves, existed since 1983 and that failure to have adequate test procedures to prevent a flow diversion of the ECCS could result in a degraded condition and prevent a safety related system from performing as design. To prevent recurrence, the licensee revised the procedure to ensure the minimum required ECCS flow is available during safety injection check valve testing. The inspectors determined that the finding represented a loss of system function and needed a detailed risk evaluation. The significance of this error was bound by using an exposure period composed of the accumulated time that this activity was performed when procedures would have allowed for this configuration. This exposure period was approximately 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />. The inspectors used the Palo Verde Standardized Plant Analysis Risk (SPAR) model, Revision 8.20, dated May 31, 2012, with a truncation limit of E-11, to perform simplified calculations. Inspectors considered one train unavailable for high pressure safety injection and only two pathways available for injection on the redundant train, as bounding assumptions for the analysis. The incremental conditional core damage probability, assuming one year of exposure, for these sequences was 3.0E-6. The change to the core damage frequency (delta-CDF) considering the 7 hour8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> exposure period was therefore: delta-CDF = 3.0E-6 * 7hour/8760 hours per year = 2.4E-9/year Since the change to the core damage frequency was less than 1.0E-7/year, the inspectors were not required to consider the contribution from external events or calculate the change to the large early release frequency. Since the calculated delta CDF was less than 1E-6, and the large early release frequency was not a significant contributor, the finding was of very low safety significance (Green). A Region IV senior reactor analyst reviewed the results and agreed with the conclusion. The licensee entered the issue into the corrective action program as PVAR 4430283. |
Site: | Palo Verde |
---|---|
Report | IR 05000528/2013005 Section 4OA7 |
Date counted | Dec 31, 2013 (2013Q4) |
Type: | NCV: Green |
cornerstone | Mitigating Systems |
Identified by: | Licensee-identified |
Inspection Procedure: | |
Inspectors (proximate) | T Brown D Reinert I Anchondo J Laughlin J O'Donnell L Carson M Baquera N Taylor S Graves |
Violation of: | 10 CFR 50 Appendix B Criterion V |
INPO aspect | |
' | |
Finding - Palo Verde - IR 05000528/2013005 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Palo Verde) @ 2013Q4
Self-Identified List (Palo Verde)
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||