05000348/FIN-2009005-03
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Finding | |
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| Title | 1-2 R Load Center Inoperability |
| Description | A NRC-identified NCV of Technical Specification (TS) 3.8.9 was identified for failure to meet the limiting condition for operation (LCO) of maintaining two trains of AC vital bus electrical power distribution subsystems operable. The licensee failed to adequately evaluate plant conditions and identify that the 1-2R 600 volt load center was unable to meet its surveillance requirement of correct breaker position and voltage for longer than the allowed outage time. The failure to properly evaluate plant conditions and recognize the surveillance requirement of TS 3.8.9 was not met was a performance deficiency. As a result, the LCO of maintaining two trains of AC vital bus electrical power distribution subsystems available was not met for longer than the allowed outage time. During the period of August 5 - August 9, 2009, (85 hours9.837963e-4 days <br />0.0236 hours <br />1.405423e-4 weeks <br />3.23425e-5 months <br /> and 6 minutes), the Unit 2 power supply to 1-2R 600 volt load center was not available to meet the Unit 2 portion of TS 3.8.9. This finding was more than minor because it adversely affected the equipment performance attribute of the mitigating systems cornerstone objective to ensure the availability, reliability and capability of systems responding to initiating events to prevent undesirable consequences. The condition resulted in the 1-2R 600 volt load center not being able to perform its automatic function during a dual unit loss of off site power (LOSP) with lossof- coolant accident (LOCA) on the specified unit. This finding was assessed using the Phase 1 screening worksheet of the SDP and determined to require a Phase 2 analysis because the condition existed longer than the allowed outage time for a single train of safety-related equipment. A Senior Reactor Analyst performed a Phase 3 evaluation under the Significance Determination Process and determined that the finding was of very low safety significance (Green). Although only one power source to the 1-2R 600 VAC Load Center was out of service, the analysis assumed the load center was totally out of service. Also, for ease of analysis a 112 hour0.0013 days <br />0.0311 hours <br />1.851852e-4 weeks <br />4.2616e-5 months <br /> exposure time was used. The dominant accident sequence was a dual unit loss of offsite power (LOSP) due to severe weather and a loss of emergency diesel generators (EDGs) resulting in a station blackout (SBO). While in the SBO condition, the TDAFW train would have failed and offsite power would not have been restored prior to core damage. This finding was assigned a cross-cutting aspect in the work practices component of the human performance area (H.4(b)) because the licensee failed to execute the sequence required by its restoration tagout procedure controlling plant configuration |
| Site: | Farley  |
|---|---|
| Report | IR 05000348/2009005 Section 1R15 |
| Date counted | Dec 31, 2009 (2009Q4) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | E Crowe S Shaeffer W Rogers G Macdonald B Caballero S Sandal |
| CCA | H.8, Procedure Adherence |
| INPO aspect | WP.4 |
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Finding - Farley - IR 05000348/2009005 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Farley) @ 2009Q4
Self-Identified List (Farley)
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