05000482/FIN-2009006-01
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Finding | |
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Title | Failure to Report Conditions Prohibited by Technical Specifications, and Safety System Functional Failures |
Description | The inspectors identified a noncited violation of Technical Specification 5.4.1, Procedures, associated with the licensees failure to ensure that adequate procedures were available for changing modes of operation of the residual heat removal system from shutdown cooling to emergency core cooling system operation. Specifically, station procedures allowed the residual heat removal system to be realigned to the emergency core cooling system mode of operation following operation in the shutdown cooling mode with suction temperatures as high as 350F without properly cooling the entire suction header. This resulted in both trains of the residual heat removal system being inoperable during periods of operation in Modes 3 and 4. This issue was entered into the licensees corrective action program as Condition Reports 2008-3810 and 2008-4997. The performance deficiency was more than minor because it was associated with the equipment performance attribute of the Mitigating Systems Cornerstone and it directly affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Using Inspection Manual Chapter 0609, Significance Determination Process, Phase 1 Worksheet, the inspectors concluded that a Phase 2 evaluation was required because this finding represented a loss of safety function of the residual heat removal system. The inspectors performed a Phase 2 analysis using Appendix A, Determining the Safety Significance of Reactor Inspection Findings for At-Power Situations, of Inspection Manual Chapter 0609, Significance Determination Process, and the plant specific Phase 2 presolved tables and worksheets for Wolf Creek. The inspectors determined that the Phase 2 presolved tables and worksheets did not contain appropriate target sets to accurately estimate the risk input of the finding. Therefore, it was determined that a Phase 3 analysis was required. Senior risk analysts performed a Phase 3 analysis of this issue. The estimated Conditional Core Damage Probability was determined to be 2.84E-7, and the estimated Conditional Large Early Release Probability was determined to be 2.72E-9. Based on these results, the finding was determined to be of very low safety significance. This finding was determined to have a crosscutting aspect in the area of Problem Identification and Resolution associated with the corrective action program P.1(c), in that the licensee failed to appropriately and thoroughly evaluate problems such that the resolutions address the causes (Section 2.2) |
Site: | Wolf Creek ![]() |
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Report | IR 05000482/2009006 Section 4OA2 |
Date counted | Sep 30, 2009 (2009Q3) |
Type: | NCV: Green |
cornerstone | Mitigating Systems |
Identified by: | NRC identified |
Inspection Procedure: | IP 71152 |
Inspectors (proximate) | A Zoulis J Josey M Young V Gaddy M Runyan |
CCA | P.2, Evaluation |
INPO aspect | PI.2 |
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Finding - Wolf Creek - IR 05000482/2009006 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Wolf Creek) @ 2009Q3
Self-Identified List (Wolf Creek)
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