05000321/FIN-2014004-05
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Finding | |
|---|---|
| Title | Licensee-Identified Violation |
| Description | 10 CFR Part 50 Appendix B, Criterion V, requires in part that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions. Contrary to the above, on June 6, 2014, the licensee failed to accomplish installation of thermal overload (TOL) heaters for 1X41-C002B using actual fan running current in accordance with procedure 52PM-R24-001-0, Allis Chalmers Low Voltage MCC Inspection. The design group based the TOL heaters on motor name plate data and did not consider actual motor running amps. This violation was determined to require a detailed risk (Phase 3) analysis because there was an actual loss of function for greater than the TS AOT. A Senior Reactor Analyst performed a Phase 3 analysis using the NRCs Hatch PRA model modified to include the EDG room ventilation fan breakers including common cause failure terms. Since the EDG 1B fan breakers were not included in the licensee breaker upgrade program, they were not included in the common cause assumptions. The licensee had performed an analysis that showed the EDGs would remain functional with any one of the three fans operating. The screening analysis conservatively assumed complete failure of one of the large room fans, an increase in the common cause failure rate, and no recovery of the tripped breakers. The dominant sequences involved a Loss of Offsite Power initiator, independent failure of the EDG 1B fans, common cause failure of the EDG 1A and 1C fans, and no recovery of the EDGs or offsite power for 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />. The second EDG 1A room fan breaker was found tripped due to a cause not part of the performance deficiency, and was assumed to fail at its normal rate. Because of the short exposure time and the lack of a common cause failure of fan breakers for the 1B EDG, the finding screened well below the 1E- 6 threshold. Therefore, this finding was determined to be of very low safety significance (Green). This condition was documented in the licensees corrective action program as CR 835377. |
| Site: | Hatch  |
|---|---|
| Report | IR 05000321/2014004 Section 4OA7 |
| Date counted | Sep 30, 2014 (2014Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | Licensee-identified |
| Inspection Procedure: | |
| Inspectors (proximate) | D Hardage D Retterer M Franke T Su |
| Violation of: | 10 CFR 50 Appendix B Criterion V Technical Specification Technical Specification - Procedures |
| INPO aspect | |
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Finding - Hatch - IR 05000321/2014004 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Hatch) @ 2014Q3
Self-Identified List (Hatch)
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