05000482/FIN-2012002-03
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Finding | |
|---|---|
| Title | Loss of Configuration Control Causes Loss of All Non-Vital Power |
| Description | Inspectors identified a non-cited violation of Technical Specification 5.4.1.a, Procedures, for implementation of an unauthorized modification by using a clearance order and a temporary procedure. This left the power source to a temporary protective relay unprotected. When another clearance order was being placed for main generator work, the temporary relay power source was lost when fuses were removed which supplied power to the temporary relay. This tripped the offsite power breaker to 13.8kV bus PA01 and tripped PA01 distribution breakers on January 24, 2012. Safety busses were unaffected because they were cross tied and being supplied by the No. 7 transformer. All non-vital systems lost power including normal service water which was removing core decay heat until operators could manually start and align essential service water pumps. Power to all systems was restored within approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The inspectors found that the installation of temporary equipment was an unevaluated long standing practice. The temporary procedure was consistent with a system operating procedure when it was approved on January 17, 2012. This conclusion differed from Wolf Creeks apparent cause determination which did not identify the issue as an unevaluated modification. The inspectors concluded that they added value and considered the issue NRC identified. Initially, corrective actions included changing the clearance order to prevent removing of fuses to the temporary relay. After inspector questions, Wolf Creek blocked the use of the temporary procedure and procedure SYS MA-120 until further evaluation was completed. This has been entered into the corrective action program as condition reports 48182, 48642, and 51408. Failure to control system configuration such that unplanned loss of power would not occur is a performance deficiency. The inspectors determined that this finding was more than minor because it impacted the mitigating systems cornerstone and its objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences (i.e., core damage). Specifically, it impacted the configuration control attribute of shutdown equipment lineup which created a loss of offsite power to 13.8kV bus PA01. The inspectors screened the loss of service water pumps B and C, A and B circulating water pumps, vital air conditioning units, emergency diesel generator starting air compressors, transformer XNB01 cooling fans, heat tracing, auxiliary boiler steam heating, the condensate storage tank makeup pump, and the refueling water storage tank makeup pump to Manual Chapter 0609, attachment G, checklist 4. Wolf Creek had inventory in the pressurizer with a time to boil greater than 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The inspectors screened the finding to Green or very low safety significance because it did not involve a loss of reactor coolant system inventory, did not affect reactor coolant system level instrumentation, did not affect the licensees ability to terminate a leak path, did not affect the licensees ability to add reactor coolant system inventory when needed, or degrade the licensees ability to recover decay heat removal once it was lost. Additionally, the inspectors screened the loss of the electric fire pump and jockey (keep full) fire pump to Inspection Manual Chapter 0609.04. Specifically, these pumps were out of service for less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and therefore, screened to Green or very low safety significance. The inspectors identified that the cause of the finding had a human performance cross-cutting aspect in the area of resources because the loss of power was caused by a lack of complete, accurate and up-to-date design documentation, procedures, drawings, fuse labeling, and work orders necessary to support the temporary configuration established through TMP 12-001 |
| Site: | Wolf Creek  |
|---|---|
| Report | IR 05000482/2012002 Section 4OA3 |
| Date counted | Mar 31, 2012 (2012Q1) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | C Peabody Z Hollcraft G Callaway J Melfi N O'Keefe C Long |
| CCA | H.7, Documentation |
| INPO aspect | WP.3 |
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Finding - Wolf Creek - IR 05000482/2012002 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Wolf Creek) @ 2012Q1
Self-Identified List (Wolf Creek)
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