05000445/FIN-2011007-02
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Failure to Identify and Mitigate or Correct Potential Single Spurious Fire Damage Scenario |
| Description | The team identified a noncited violation of License Condition 2.G for failure to implement and maintain in effect all provisions of the approved fire protection program. Specifically, the licensee failed to recognize that electrical cables for the pressurizer power-operated relief valves and associated block valves were installed in many of the same cable trays, leaving the plant susceptible to fire damage that could spuriously open the power-operated relief valve and prevent the ability to shut the block valve. This scenario could challenge operators by creating a loss of coolant during a plant fire. The licensee entered this issue into their corrective action program as Condition Reports CR-011-001319, CR-2011-001807, CR-2011-001808 and CR-2011-002430. As a compensatory measure, the licensee revised attachment 17 to Procedure ABN-901 , Fire Protection System Alarms or Malfunctions, Revision 9, to close the affected pressurizer block valves in the event of a fire in the Auxiliary or Safeguards buildings in order to mitigate potential circuit interactions that could spuriously open a poweroperated relief valve. Failure to identify and mitigate or correct an existing plant configuration that was susceptible to single spurious failures while performing expert panel reviews of fire damage scenarios that could prevent safely shutting down the plant in the event of a fire is a performance deficiency. This performance deficiency was more than minor because it is associated with the protection against external events (fire) attribute of the Mitigating Systems cornerstone and it adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. The team used Manual Chapter 0609, Appendix F, Fire Protection Significance Determination Process, because the performance deficiency affected fire protection defense-in-depth strategies involving post-fire safe shutdown. Because the Phase 1 screening criteria were not met, the analysis continued to Phase 2. Because the finding did not screen as Green during the Phase 2 analysis, a senior reactor analyst performed a Phase 3 analysis. Using information from the Phase 2 worksheets and discussions with the licensee PRA staff, the senior reactor analyst\\\'s Phase 3 analysis calculated the total change in core damage frequency to be 3.2E-7/yr (Green), based on the proximity of fire sources available to damage these circuits. This finding had a crosscutting aspect in the area of problem identification and resolution associated with the corrective action program component because the licensee did not identify the issues completely, accurately, and in a timely manner commensurate with their safety significance while conducting expert panel reviews of this and other scenarios in 2009. |
| Site: | Comanche Peak  |
|---|---|
| Report | IR 05000445/2011007 Section 1R05 |
| Date counted | Jun 30, 2011 (2011Q2) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.05 |
| Inspectors (proximate) | J Bowen J Mateychick J Watkins N O'Keefe N Okonkwo S Alferink S Graves |
| INPO aspect | |
| ' | |
Finding - Comanche Peak - IR 05000445/2011007 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Comanche Peak) @ 2011Q2
Self-Identified List (Comanche Peak)
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||