05000445/FIN-2013005-03
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Notice of Enforcement Discretion 13-4-004 for a Loss of Both Required Offsite Power Circuits |
| Description | On December 4, 2013, the two required offsite circuits to both Units 1 and 2 safety-related 6.9 kV buses became inoperable during planned modification work to install an additional 138 kV transformer (XST1A). As a result of the event, the licensee declared an Unusual Event. The inspectors responded to the control room to access the operators performance, procedure usage, and proper emergency plan declaration. The inspectors performed a walkdown of the control boards to verify appropriate equipment response following the loss of offsite power. The inspectors discussed the event with licensee personnel and the control room staff. Power was lost to the 345 kV transformer (XST2), which at the time was providing power to the 6.9 kV safeguards buses for both Units 1 and 2, when the licensee inadvertently cut into an energized 6.9 kV cable for transformer XST2, rather than the de-energized cable for transformer XST1. At 1:41 pm, both units entered Technical Specification 3.8.1, AC Sources - Operating, Condition C, Required Action C.2, restore one required offsite circuit to operable status with a completion time of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. If the completion time of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is not met, then both units would be required to enter Condition G and be in Mode 3 in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and Mode 5 in 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The licensee requested a notice of enforcement discretion and an additional 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> to restore transformer XST1 or XST2, such that the completion time of Required Action C.2 would expire at 3:41 a.m. on December 6, 2013. A notice of enforcement discretion was granted by the NRC staff at 1:00 p.m. on December 5, 2013. Consistent with NRC policy, the NRC agreed not to enforce compliance with the specific technical specifications in this instance, but will further review the cause(s) that created the apparent need for enforcement discretion to determine if there is a performance deficiency, if the issue is more than minor, or if there is a violation of requirements. This issue will be tracked as an unresolved item (URI)05000445/2013005-03; 05000446/2013005-03, Notice of Enforcement Discretion 13-4-004 for a Loss of Both Required Offsite Power Circuits. |
| Site: | Comanche Peak  |
|---|---|
| Report | IR 05000445/2013005 Section 4OA3 |
| Date counted | Dec 31, 2013 (2013Q4) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | D Strickland J Dixon J Kramer L Carson N Greene N Okonkwo P Elkmann R Kumana W Walkerd Proulxg Guerra J Kramer J Watkins L Brandt L Carson N Greene R Kumana S Alferink W Sifre W Walker |
| INPO aspect | |
| ' | |
Finding - Comanche Peak - IR 05000445/2013005 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Comanche Peak) @ 2013Q4
Self-Identified List (Comanche Peak)
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||