10 CFR 50, Appendix B, Criterion V, Instructions, Procedures and Drawings, requires, in part that activities affecting quality shall be prescribed by documented drawings and shall be accomplished in accordance with these drawings. Drawings shall include appropriate quantitative or qualitative acceptance criteria for determining that important activities have been satisfactorily accomplished. Contrary to the above, on January 30, 2008, while performing field walk downs of the interior doghouses for Unit 1 and Unit 2, the licensee determined that they had failed to include appropriate quantitative or qualitative acceptance criteria for ensuring that flow restrictor and cover plates on floor drains that connected the interior doghouse area to the
auxiliary feedwater pump rooms had been installed in accordance with initial construction drawings. The failure to install these plates as required by construction drawings had the potential to result in the loss of all three
auxiliary feedwater pumps in the event of a
feedwater line break within the interior doghouse. A Region II senior risk analyst performed a Phase 3 risk analysis for the condition. The numerical risk of this deficiency was dominated by a sequence that involves the common cause failure of the
feedwater isolation switches, circuitry, and isolation valves to isolate main
feedwater entering the respective unit\\\'s interior doghouse given a
feedwater line break. This
leads to the flooding of
mitigating systems (i.e.,
auxiliary feedwater pumps located at lower elevations within the auxiliary building). The Phase 3 analysis results were dominated by Human Reliability Analysis assumptions, estimates of common cause failure rates, and estimates of pipe break frequencies. The analysis determined that the risk increase over the base case was less than
1E-6 and is considered to be of very low safety significance. This issue is documented in the licensees
CAP as
PIP C-08-00513. The documents reviewed during this inspection are listed in the Attachment to this report
