05000482/FIN-2008010-03
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Finding | |
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| Title | Changes to the Approved Fire Protection Program May Not Meet NRC Acceptance Criteria |
| Description | The team identified an unresolved item concerning changes made to the NRC-approved fire protection program that potentially adversely affected the ability to achieve and maintain safe shutdown in the event of a fire without prior NRC staff approval. Specifically, the licensee changed the approved fire protection program to allow some voiding in the core in the event of a control room fire which caused a pressurizer power-operated relief valve to spuriously open. Description. During a triennial fire protection inspection in 2005, the team identified an apparent violation concerning the failure to assure reactor coolant system subcooling during an alternative shutdown with both pressurizer power-operated relief valves spuriously opening due to fire damage. This issue was documented as Apparent Violation 05000482/2005008-02, Failure to Maintain Reactor Coolant System Subcooling During the Alternative Shutdown. Calculation AN-02-021, OFN RP-017, Control Room Evacuation Consequence Evaluation, Revision 0, had predicted reactor coolant system subcooling margin would not be maintained, significant voiding would occur in the core, and a steam void would form in the reactor vessel head during an alternative shutdown scenario with both pressurizer power-operated relief valves spuriously opening. The licensee had concluded this was acceptable since the calculation demonstrated the void formation would be limited, natural circulation would be maintained in the reactor coolant system, sufficient decay heat removal would be maintained, and no fuel damage would occur. This violation was treated as an apparent violation because the team determined it met the criteria of the NRC Enforcement Manual, Section 8.1.7.1 for deferring enforcement actions for postulated fire induced circuit failures. The licensee considered the spurious opening of both pressurizer power-operated relief valves to be outside of the plant licensing basis for the fire protection program since multiple spurious operations were necessary for this condition to occur. The NRC has been working to clarify the regulatory requirements for addressing multiple spurious actuations. Since the 2005 triennial fire protection inspection, the licensee made significant changes to the alternative shutdown methodology implemented by Procedure OFN RP-017, Control Room Evacuation. The licensee also developed Report E-1F9915, Design Basis Document for OFN RP-017, Control Room Evacuation, Revision 0, and Evaluation SA-08-006, RETRAN-3D Post-Fire Safe Shutdown (PFSSD) Consequence Evaluation for a Postulated Control Room Fire, Revision 0, to demonstrate the adequacy of the revised alternative shutdown procedure. These new evaluations predicted that a fire in the control room causing a single pressurizer power-operated relief valve to spuriously open could cause a steam bubble to void approximately 40 percent of the reactor vessel head. The team performed walkthroughs of the revised alternative shutdown procedure with both licensed and non-licensed operators. The team confirmed that the operators could perform all time critical steps within the limits used to develop Report E-1F9915 and Evaluation SA-008-006. The team was initially unable to confirm the adequacy of the current alternative shutdown procedure because Evaluation SA-008-006 did not present enough parameters to demonstrate plant performance and did not include specific acceptance criteria. The licensee was able to revise the evaluation to include enough plant parameters to demonstrate plant performance and provided a statement of the acceptance criteria which were used to conclude the plant performance was acceptable. The approved fire protection program appeared to require the licensee to meet the requirements of 10 CFR Part 50, Appendix R, Section III.L.Section III.L states, in part, that, During the post-fire shutdown, the reactor coolant system process variables shall be maintained within those predicted for a loss of normal a.c. power. However, one of the acceptance criteria used in Evaluation SA-008-006 states, It is not necessary to maintain reactor process variables within those predicted for a loss of normal a.c. power as long as the analysis demonstrates that a control room fire will not result in the plant reaching an unrecoverable condition, which could lead to core damage. The licensee stated that their current licensing basis allowed them to use the prevention of an unrecoverable condition, citing letter SLNRC 84-0109, dated August 23, 1984. This letter provided the staff with the SNUPPS response plan for a postulated control room fire. It noted that implementation of the response plan for a control room fire would ensure that the plant would not reach an unrecoverable condition which could result in core damage. The team noted that the licensee did not identify this as a deviation from the requirements of 10 CFR Part 50, Appendix R, Section III.L.1, nor did the NRC approval of the alternative shutdown approach in the safety evaluation report (NUREG-0881, Supplement Number 5) acknowledge any such deviation. License Condition 2.C.(5).(b) states, The licensee may make changes to the approved fire protection program without prior approval of the Commission only if those changes would not adversely affect the ability to achieve and maintain safe shutdown in the event of a fire. The team was concerned that the licensee changed the fire protection program in a manner that could adversely affect the ability to achieve and maintain safe shutdown in the event of a fire without prior NRC approval. However, the staff is conducting additional reviews to determine whether the license condition could allow the licensee to use different criteria to determine the acceptability of an adverse effect than the criteria used by the NRC. Changing the approved fire protection program in a manner that could adversely affect the ability to achieve and maintain safe shutdown in the event of a fire without prior NRC staff approval was potentially a performance deficiency. The team determined that this may be more than minor because it was associated with the Protection Against External Factors attribute of the Mitigating Systems Cornerstone and could affect the availability, reliability, and capability of systems that respond to fire events to prevent undesirable consequences. The licensee implemented an hourly fire watch in the control room as a compensatory measure. The licensee entered this issue into their corrective action program as Condition Report 2008-005208. Additional NRC action is needed to determine whether this issue involves a performance deficiency and to determine significance. This issue does not involve a current safety concern because Evaluation SA-08-006 demonstrated that no core damage would occur and steam voiding in the reactor could be corrected. License Condition 2.C.(5).(b) states that the licensee may make changes to the approved fire protection program without prior approval of the Commission only if those changes would not adversely affect the ability to achieve and maintain safe shutdown in the event of a fire. The approved fire protection program appears to require that the licensee meet the technical requirements of 10 CFR Part 50, Appendix R, Section III.L.Section III.L requires that the reactor coolant system process variables be maintained within those predicted for a loss of normal a.c. power during the post-fire shutdown. The team was concerned that the licensee was not meeting the technical requirements of 10 CFR Part 50, Appendix R, Section III.L. Specifically, the team was concerned that the licensee did not assure that the reactor coolant system process variables would be maintained within those predicted for a loss of normal a.c. power during the post-fire shutdown, as demonstrated by the presence of voiding in the core. The team was able to confirm that the licensee demonstrated no fuel damage would occur in an alternative shutdown scenario due to a control room fire with a single pressurizer power-operated relief valve spuriously opening. The team was also concerned that the licensee made changes to the approved fire protection program that could adversely affect the ability to achieve and maintain safe shutdown in the event of a fire without prior approval of the Commission. Specifically, the team was concerned that the licensee changed the approved fire protection program to allow voiding in the core in the event of a control room fire which caused a pressurizer power-operated relief valve to spuriously open, contrary to the requirements of 10 CFR Part 50, Appendix R, Section III.L. The team believes that this change is considered an adverse effect on the ability to achieve and maintain safe shutdown. Pending a final staff position to determine whether this concern involved a violation of NRC requirements and analyses to determine the safety significance of this finding, this issue is being treated as an unresolved item: URI 05000482/2008010-03, Changes to the Approved Fire Protection Program May Not Meet NRC Acceptance Criteria |
| Site: | Wolf Creek  |
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| Report | IR 05000482/2008010 Section 1R05 |
| Date counted | Dec 31, 2008 (2008Q4) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.05 |
| Inspectors (proximate) | C Long C Peabody G Miller G Werner M Shannon N O'Keefe P Jayroe R Kellar S Garchowa Dahburj Adams J Mateychick N Okonkwo |
| INPO aspect | |
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Finding - Wolf Creek - IR 05000482/2008010 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Wolf Creek) @ 2008Q4
Self-Identified List (Wolf Creek)
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