I. PURPOSE AND SCOPE

Methods to analyze the adequacy of equipment to withstand seismic events have changed in the years since the Brunswick plant was designed and constructed. Because of these changes in methodologies, the seismic margins of older equipment are unknown. NRC resolution of Unresolved Safety Issue (USI) A-46, "Seismic Qualification of Equipment in Operating Nuclear Power Plants," is promulgated in NRC Generic Letter 87-02 and requires all utilities whose plants are not qualified to current criteria to evaluate their electrical and mechanical equipment required for hot shutdown for adequate seismic qualification. The Seismic Qualification Utility Group (SQUG), of which CP&L is a member, developed general implementing guidance for performing the reviews. NRC approved the use of this guidance in a Safety Evaluation Report dated May 22, 1992.

The purpose of this project is to implement the resolution of USI A-46 by analyzing the seismic adequacy of Brunswick electrical and mechanical equipment required to accomplish and maintain the plant in a hot safe shutdown condition for 72 hours. Also included in the scope of this project is the evaluation of outliers and the scoping of modifications to address any deficient conditions found during the effort. Separate PCN's will cover any modifications performed as a result of this project. The final product will be a report documenting the results of the review, including any deficiencies that will require correction.

Assurance that all safety-related electrical and mechanical equipment can perform their intended functions during and following a seismic event or identification of corrective actions to resolve deficient conditions will constitute successful completion of this project. Further assurance of successful completion will be evidenced by NRC review and acceptance of Brunswick's implementation of USI A-46.

II. EVALUATION

Schedule Index: 30 - This initiative could have a significant impact on future analyses of external events. All systems would be affected by a seismic event and severe consequences could result if equipment is not assured of meeting the specified qualification criteria, resulting in a significant impact on the core damage frequency due to seismic events (1.0 x 32). Verifying seismic qualification will require personal inspection and system walkdowns in radiation areas and result in exposure to workers. This exposure will not be made up by any ALARA benefits afforded by the project over the lifetime of the plant, therefore resulting in a negative ALARA scaling factor (-0.2 x 9).

Economic Aspects: The project requires a short-term investment to conduct the system inspections and walkdowns, with no identified positive or negative economic benefits extending beyond the completion of the project. Additional projects identified to correct deficiencies identified during the walkdowns will be performed under separate PIDs.

Related Standards: The Work Management Policy on material condition is applicable to this project.

Other Considerations: The project will be performed under the guidelines of the General Implementing Procedure developed by SQUG. NRC approval of the procedure has been obtained. BNP is drafting its response to the NRC that identifies any deviations from the guidance and the expected completion dates for the reviews. Estimated outages for conducting walkdowns and inspections are B110R1 for Unit 1 and B212R1 for Unit 2. After the study is completed, a report will be prepared and submitted to NRC that documents the results and describes the schedule for correcting any deficiencies identified during the review. Margins for the plant with respect to seismic events as required for the Individual Plant Examination External Events (IPEEE) analysis will also be established in concert with this project.

III. CONCLUSION

Because the methods used in seismically qualifying safety-related systems were not as capable as current methodologies, plant systems will be reviewed to assure the capability to perform their functions during and after a seismic event. The NRC has expressed its concerns on this issue and recommended actions to be taken by licensees in Generic Letter 87-02. SQUG, of which Brunswick is a participant, prepared and submitted to NRC generic implementing guidance for reviewing seismic qualification of equipment. Brunswick is currently preparing its response to the NRC's Safety Evaluation Report on the generic implementing guidance. This response will specify Brunswick's plan and schedule to complete the reviews.