The team identified a cited violation of License Condition 2.C.(10), Fire Protection, for failing to ensure that the Division 1 standby
service water support system to the Division 1
emergency diesel generator, which was required to achieve
safe shutdown, was protected such that it remained free from fire damage under all conditions. This condition was identified by the licensee in May 2007, and entered into their corrective action program as a significant non-conforming condition in CRRBS- 2007-02102. The licensee subsequently initiated compensatory measures in the form of manual actions to protect the Division 1
emergency diesel generator. This issue was documented as a licensee-identified noncited violation in Inspection Report 2009002. River Bend has subsequently completed two refueling outages, six forced outages, and one
emergency diesel generator work window of sufficient duration since identification of this condition and failed to correct the nonconformance. The team determined that schedule changes resulted in a new completion date of January 2011. The failure to ensure that one train of systems necessary to achieve and maintain hot shutdown conditions from either the control room or emergency control station(s) was free of fire damage and to correct this significant non-conforming condition in a timely manner is a performance deficiency. This performance deficiency was more than minor because it was associated with the protection against external factors (fire) attribute of the
Mitigating Systems Cornerstone and adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to
initiating events in order to prevent undesirable consequences. The team evaluated this deficiency using
Inspection Manual Chapter 0609, Appendix F, Fire Protection
Significance Determination Process, because it affected fire protection defense-in-depth strategies involving post fire
safe shutdown systems with plant-wide consequences. A Phase 3
SDP risk assessment was performed by a senior reactor analyst. The bounding change in conditional core damage frequency for a 1-year exposure is the Fire Mitigation Frequency (4.30E-08/year) multiplied by the change in conditional core damage probability (0.9) for a value of 3.87E-08/year. This value indicates the finding has very low safety significance (Green). Because - 5 - Enclosure the licensee failed to correct this violation, this violation is being treated as a cited violation, consistent with the
NRC Enforcement Policy. This finding had a crosscutting aspect in the Work Control component of the Human Performance area because the licensee did not appropriately plan work activities to support long-term equipment reliability by limiting
temporary modifications, operator workarounds, safety systems unavailability, and reliance on manual actions
H.3(b). (Section 1R05.01
