The inspectors reviewed the reportability evaluations associated with the unsatisfactory penetrations. The inspectors questioned the adequacy of these evaluations in that they estimated that a significant level of water (approximately three to four feet) would accumulate in the turbine building during
PMH conditions, but concluded that none of this flood water would pass through the set of fire doors from the turbine building to the auxiliary building. The subject fire doors are rated for 2 feet of water pressure. The reportability evaluations heavily relied upon actions taken in the licensees adverse weather procedure EM-220, Violent Weather, to sandbag the fire doors prior to hurricane conditions. The inspectors did not have confidence in the adequacy of sandbagging instructions in EM-220 or that the door could withstand three to four feet of turbine building flooding to preclude flooding in auxiliary building. As a result of the inspectors concerns, the licensee initiated CR 563931 to re-evaluate the expected flood levels in the turbine building during
PMH conditions. The inspectors reviewed the completed evaluation and noted that more reasonable external flooding conditions were used and the evaluation took credit for other actions in the adverse weather procedure such as use of dewatering pumps. The inspectors also noted that the evaluation included the estimated flooding contribution from two additional unsatisfactory penetrations which were identified in August 2012 during the licensees Fukushima flooding walkdowns and documented in CRs 556385 and 557156. The inspectors concluded that, due to the location and condition of the two penetrations, their overall flooding contribution was negligible when compared to the overall flood level due to the 29 penetrations previously identified by the licensee. The new evaluation concluded that the resulting flood level through the 29 penetrations during
PMH conditions would be 1.27 feet of water in the turbine building, which is within the rating of the fire doors. The inspectors concurred with the licensees conclusion that this flood level would not adversely impact the allowable flood limit in the auxiliary building. The inspectors verified that the licensee had performed an adequate extent of condition review to identify the unsatisfactory below grade penetrations and that appropriate actions were being taken to correct the issue. The inspectors verified that, as of the end of this inspection period, 19 of the 28 unsatisfactory penetrations had been repaired. The remaining were scheduled for repair.
