05000397/FIN-2014003-09
Finding | |
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Title | Licensee-Identified Violation |
Description | Technical Specification 3.7.1, Standby Service Water (SW) System and Ultimate Hea
Sink (UHS), requires, in part, that the Division 1 and 2 SW subsystems and UHS shal be operable in Modes 1, 2 and 3. The technical specification requires that with on SW subsystem inoperable, the licensee must either restore the inoperable subsystem to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, or place the unit in Mode 3 within the next twelve hours and in Mode 4 within the following 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. Contrary to the above, from September 6, 2013 until March 12, 2014, the Division 2 service water subsystem wa inoperable due to a degraded tornado missile barrier and action was not taken to restor the inoperable service water subsystem to an operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or to plac Columbia Generating Station in Mode 3 within the following 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. This finding wa identified by the licensee and entered in the licensees corrective action program as A 304266. The senior resident inspector performed the initial significance determinatio for the performance deficiency using NRC Inspection Manual 0609, Appendix A, Exhibi 4, External Events Screening Questions, dated July 1, 2012. The finding required detailed risk evaluation because it involved the potential loss of one train of a ris significant system. Therefore, a Region IV senior reactor analyst performed a boundin detailed risk evaluation. The bounding change to the core damage frequency wa 7E-8/year (Green). The dominant core damage sequences included: A tornado induce loss of offsite power, tornado induced loss of all the Division II trains, random failures o the Division I and III emergency diesel generators, and failure to recover either offsit power or an emergency diesel generator in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The low tornado induced loss o offsite power initiating event frequency and the reactor core isolation cooling syste helped to minimize the risk significance. |
Site: | Columbia ![]() |
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Report | IR 05000397/2014003 Section 4OA7 |
Date counted | Jun 30, 2014 (2014Q2) |
Type: | NCV: Green |
cornerstone | Mitigating Systems |
Identified by: | Licensee-identified |
Inspection Procedure: | |
Inspectors (proximate) | B Baca D Bradley D Reinert J Groom L Ricketson N Taylor P Elkmann |
Violation of: | Technical Specification |
INPO aspect | |
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Finding - Columbia - IR 05000397/2014003 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Columbia) @ 2014Q2
Self-Identified List (Columbia)
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