05000458/FIN-2011008-06
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Finding | |
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| Title | Failure to Obtain NRC Approval for Change to Ultimate Heat Sink Inventory Requirements |
| Description | The team identified a Severity Level IV, noncited violation of 10 CFR 50.59, Changes, Tests and Experiments which states, in part, that a licensee shall obtain a license amendment pursuant to Section 50.90 prior to implementing a proposed change, test, or experiment if this activity would; result in more than a minimal increase in the likelihood of occurrence of a malfunction of a SSC important to safety previously evaluated in the final safety analysis report (as updated). Specifically, from December 16,2002, to October 27,2011, the licensee changed the design basis of the ultimate heat sink inventory requirements to provide a 30-day cooling water supply without makeup capability to providing a less than 30-day cooling water supply with makeup capability without obtaining a license amendment. This finding was entered into the licensee\'s corrective action program as Condition Report CR 2011-07674. The team determined that the failure to obtain a license amendment prior to implementing a proposed change, test or experiment to the ultimate heat sink requirements was a performance deficiency. The performance deficiency was evaluated using traditional enforcement because the finding has the ability to impact the regulatory process. The finding was more than minor because it involved a change to the updated final safety analysis report description where there was a reasonable likelihood that the change would require NRC approval. In accordance with the NRC Enforcement Policy, the team used insights from MC 0609, Significance Determination Process, to determine the final significance of the finding. In accordance with NRC Inspection Manual Chapter 0609, Attachment 4, Phase 1 - Initial Screening and Characterization of Findings, the finding represented a loss of system safety function in that the ultimate heat sink could not meet its 30-day mission time to provide decay heat removal. Therefore, a Phase 2 evaluation was necessary. The significance of the finding could not be assessed quantitatively through a Phase 2 or Phase 3 analysis. Consequently, an assessment was performed in accordance with IMC 0609, Appendix M, Significance Determination Process Using Qualitative Criteria. The finding was determined to have very low safety significance because the frequency of events that would require long term use of the ultimate heat sink is very low and the difference in the failure probability to replenish the ultimate heat sink in 10 days versus 30 days is very small. This was because an early depletion of the inventory would be easily detected and would become a priority. At the time that replenishment would be needed, plant conditions should be stable and local transportation arteries should be restored. Therefore, since the finding had very low safety significance, the finding was determined to be Severity Level IV, in accordance with the NRC Enforcement Policy. This finding did not have a crosscutting aspect because the most significant contributor did not reflect current licensee performance |
| Site: | River Bend  |
|---|---|
| Report | IR 05000458/2011008 Section 1R21 |
| Date counted | Dec 31, 2011 (2011Q4) |
| Type: | TEV: Severity level IV |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.21 |
| Inspectors (proximate) | K Clayton G George T Farnholtz S Makor N Greca C Edwards J Braisted B Latta |
| INPO aspect | |
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Finding - River Bend - IR 05000458/2011008 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (River Bend) @ 2011Q4
Self-Identified List (River Bend)
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