05000382/FIN-2016001-01
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Finding | |
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| Title | Failure to Assess and Manage the Increase in Risk from Emergent Maintenance Activities |
| Description | The inspectors identified a non-cited violation of 10 CFR 50.65, Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, section a(4), for the licensees failure to assess and manage the increase in risk during an auxiliary component cooling water system work window. Specifically, the licensee failed to re-asses risk when a dry cooling tower fan in the component cooling water system was declared unavailable during the ongoing auxiliary component cooling water system work window. As a result, for approximately 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, on-line risk was maintained as Green when it should have been elevated to Orange, which would have required additional risk management actions. The licensee entered this issue into their corrective action program as Condition Report CR-WF3-2016-0660. Corrective actions included restoring the dry cooling tower fan to available status such that risk returned to Green and sending a communication to operations supervisors to re-emphasize the requirements to adequately address unavailability of plant components. The inspectors determined that the performance deficiency was more than minor, and therefore a finding, because it was associated with the configuration control attribute of the Mitigating Systems Cornerstone, and adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, by not ensuring the risk assessment was adequate when an additional component was emergently declared unavailable, the licensee proceeded with a maintenance work window with no understanding of the increased risk associated with a different plant configuration. The inspectors used Inspection Manual Chapter 0609, Appendix K, Maintenance Risk Assessment and Risk Management Significance Determination Process, dated May 19, 2005, Flowchart 1, Assessment of Risk Deficit, and determined the need to calculate the risk deficit to determine the significance of this issue. The risk deficits were assumed to be equal to the incremental core damage probability (ICDP)actual and incremental large early release probability (ILERP)actual. The Waterford probabilistic risk assessment model yielded an incremental core damage probability (ICDP), or actual increase in risk during this work window, of 6.1x10-8. The regional senior reactor analyst evaluated the licensees risk significance evaluation and agreed with the results from the licensees model. The ILERP, screened out as not risk significant. In accordance with Flowchart 1 in Appendix K, because the ICDP was less than 1x10-6 and the ILERP was less than 1x10-7, the finding screened as having very low safety significance (Green). This finding has a procedure adherence cross-cutting aspect in the area of human performance, because individuals did not follow processes, procedures, and work instructions. Specifically, when the additional dry cooling tower fan was declared unavailable, the licensee did not re-assess risk as soon as practical as specified in site procedures [H.8]. |
| Site: | Waterford  |
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| Report | IR 05000382/2016001 Section 1R13 |
| Date counted | Mar 31, 2016 (2016Q1) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.13 |
| Inspectors (proximate) | B Hagar C Speer F Ramirez J Josey L Carson N Greene |
| Violation of: | 10 CFR 50.65 |
| CCA | H.8, Procedure Adherence |
| INPO aspect | WP.4 |
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Finding - Waterford - IR 05000382/2016001 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Waterford) @ 2016Q1
Self-Identified List (Waterford)
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