05000390/FIN-2011005-03
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Finding | |
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| Title | Failure to comply with Technical Specification Requirement 3.8.4.14 for Vital Batteries III and IV |
| Description | On February 13, 2011, Vital Battery IV was tested per 0-SI-236-54, 125 VDC Vital Battery IV 60 month Performance Test and 125 VDC Vital Battery Charger IV Test, as required by Technical Specification 3.8.4, surveillance requirement 3.8.4.14 which requires, in part, that the battery capacity be Y 80% of the manufacturer s rating. The battery tested at 82.5% capacity, down from 108.75% at its last test performance. No additional actions were taken at that time. In June 2011, the licensee noted that cell # 51, was at 2.12 vdc which was out of the Category A and B limits of the associated surveillance requirement. Following cell replacement, on June 27, 0-SI-236-44, 125 VDC Vital Battery IV 18 month Service Test and Vital Battery Charger IV Test was attempted and aborted due to multiple cell voltages dropping below procedural limits. The licensee decided to replace 8 cells and re-perform the test. The test passed with no margin to support a two unit load profile requirement which was the test acceptance criteria. The licensee ordered new battery cells for both Vital Batteries IV and III. The two unit load profile had been in use on previous tests. In that Vital Battery III was the same age as Vital Battery IV, in November 2011, the inspectors inquired as to the reason for postponing the Vital Battery III performance test which had been due since November of 2010. The licensee responded that they had ordered new cells for the battery and that the cells would be replaced prior to the end of the surveillance grace period, which would end in February of 2012 and that they had confidence in Vital Battery III due to the performance of 0-SI-236-43, 125 VDC Vital Battery III 18 month Service Test and Vital Battery Charger III, in February of 2011, which showed no degradation at that time. At that point, the inspectors questioned the operability of Vital Battery III. Based on test history and battery age, batteries I, II, and V were not considered at risk for current operability. To address the current operability questions, the licensee decided to perform 0-SI-236- 53, 125 VDC Vital Battery III 60 month Performance Test and 125 VDC Vital Battery Charger III Test. Inspectors observed this test on November 21, 2011, which failed to achieve the required 80% capacity. This battery was subsequently left out of service until new cells arrived and replaced the old cells. The licensee modified the service test load profile for each battery to include only Unit 1 loads and Unit 2 loads that were connected during this period in question. This modified test was successfully performed on Vital Battery III and Vital Battery IV with the 8 new cells replaced in June. Current plans are to re-install the original 8 cells in Vital Battery IV and perform the modified service test to prove its past capability of meeting established design base loads for the time frame between February and June of 2011. The licensee plans to perform this test in January 2012. Until then, spare Vital Battery V will remain in service carrying Vital Battery IV loads. Pending this additional testing, this item is identified as URI 050000390/2011005-03, Operability concerns for Vital Batteries III and IV |
| Site: | Watts Bar  |
|---|---|
| Report | IR 05000390/2011005 Section 1R15 |
| Date counted | Dec 31, 2011 (2011Q4) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | R Monk S Shaeffer P Higgins A Vargas T Lighty K Miller T Sus Shaefferp Higgins R Baldwin K Miller W Deschaine N Childs R Monk |
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Finding - Watts Bar - IR 05000390/2011005 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Watts Bar) @ 2011Q4
Self-Identified List (Watts Bar)
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