05000259/FIN-2009002-01
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Finding | |
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| Title | Inappropriate Change to SSI Entry Conditions For Appendix R Fire Events (Section 1R15) |
| Description | On December 23, 2008, the licensee issued Revision 2 of 0-SSI-001, which instituted a significant change to the SSI Entry Conditions. In essence this revision, added an entry condition based on the operators ability to restore and maintain reactor water level above +2 inches on the narrow range scale with available equipment. With this change in effect, operators would not enter the SSIs during an Appendix R fire event unless they were unable to restore and maintain reactor water level above +2 inches. As long as operators could maintain reactor water level during a fire event, they would continue to use the Emergency Operating Instructions (EOI) in lieu of the SSIs. In January 2009, the inspectors reviewed the affect of 0-SSI-001, Revision 2, upon the operators ability to align and operate designated safe shutdown equipment in a manner that would ensure their capability to perform their intended functions during a 10CFR50, Appendix R, fire event. Based on this review, the inspectors questioned the adequacy of the revised SSI entry conditions to ensure critical parameters (e.g., Suppression Pool temperature) would be maintained consistent with assumptions in the safe shutdown analyses (SSA). Failure of the operators to enter the SSIs at the right time could invalidate the critical SSI timelines for operator actions to ensure reactor core and containment cooling functions are met. To address the inspectors concerns regarding the potential adverse impact on critical assumptions in the SSAs as a consequence of delayed entry into the SSIs by the operators, the licensee initiated PER 162431. After further review of the inspectors concerns, the licensee subsequently determined that the Entry Conditions of 0-SSI-1 did not ensure timely entry into the safe shutdown procedures in the event that decay heat removal capability was lost due to fire damage. The Revision 2 procedure change evaluation of 0-SSI-001 did not consider the potential impact on decay heat removal and containment cooling functions during a fire event. The licensee initiated PER 162779 to promptly address this specific issue. On February 9, 2009, the licensee issued Revision 3 of 0-SSI-001 which changed the Entry Conditions to include additional provisions for ensuring timely entry into the SSIs that would assure critical SSA assumptions were met to allow decay heat removal and containment cooling functions to be fulfilled. This SSI revision, and a revision to the licensees Fire Protection Report, were the primary corrective actions to resolve PER 162779. In order to address the inspectors original, overall concern, as part of the corrective actions for PER 162431, the licensee committed to conduct a comprehensive re-evaluation of the SSI entry conditions to assure they were consistent with all SSA assumptions and SSI timelines for any Appendix R fire event. [Note: following further dialogue with the NRC staff regarding acceptability of SSI entry conditions, the licensee also initiated PER 164685 and subsequently issued Revision 4 of 0-SSI-001, on February 27, 2009, which changed the Entry Conditions back to the way they were in Revision 1. The Entry Conditions prescribed by Revision 1 and 4 of 0-SSI-001 were essentially based only on the magnitude of the fire, and did not include qualifiers related to plant parameters (e.g., reactor water level, suppression pool temperature).] In order to fully assess the safety and enforcement implications regarding the adequacy of the revised SSI entry conditions, additional information from the licensee will be needed. Consequently, pending completion of the licensees comprehensive reevaluation, and further review by the NRC, this issue will be identified as URI 05000259, 260, 296/2009002-01, Inappropriate Change to SSI Entry Conditions For Appendix R Fire Events |
| Site: | Browns Ferry  |
|---|---|
| Report | IR 05000259/2009002 Section 1R15 |
| Date counted | Jun 30, 2009 (2009Q2) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | C Stancil E Guthrie J Baptist K Korth P Higgins T Rossg Pickk Miller L Suggs M Thomas P Fillion P Qualls R Neaseb Metzgerc Kontz L Suggs M Thomas P Qualls R Nease |
| INPO aspect | |
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Finding - Browns Ferry - IR 05000259/2009002 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Browns Ferry) @ 2009Q2
Self-Identified List (Browns Ferry)
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