The team identified a finding of very low safety significance, involving a non-cited violation of Seabrook Unit 1 Operating License Condition 2.F for failure to implement and maintain all aspects of the approved
Fire Protection Program. Specifically, NextEra failed to ensure that intake air to the A and B
remote shutdown panel areas was not contaminated from products of combustion resulting from a cable spreading room fire. NextEra promptly entered this issue into its corrective action program as condition reports
AR 01977233 and
AR 01982946. NextEra initiated compensatory measures in the form of four-hour roving fire watches. Long term corrective actions include determining options to eliminate the potential for smoke migration from a cable spreading room fire to the A and B essential switchgear rooms. This finding was more than minor because it was associated with the Protection Against External Factors (e.g., fire) attribute of the
Mitigating Systems Cornerstone and adversely affected the cornerstone objective to ensure the availability and reliability of systems that respond to
initiating events to prevent undesirable consequences. In accordance with
IMC 0609, Appendix F, Fire Protection
Significance Determination Process, Attachment 1, Step 1.6, a Senior Reactor Analyst examined NextEras probabilistic risk analysis based risk evaluation for the issue and determined this finding resulted in an increase in core damage frequency in the mid E-7 range (Green) or very low safety significance. This finding did not have a cross-cutting aspect because it was determined to be a legacy issue and was considered to be not indicative of current licensee performance.
