10 CFR 50.65 (a)(4) stated in part that the licensee shall assess and manage the increase in risk that may result from the proposed maintenance activities. Contrary to the above, on February 17, 2013, the licensee failed to assess and manage the risk when placing the 1A reactor building spray train in service for borated water storage tank recirculation for sampling. This condition made train A reactor building spray
inoperable. This combined with train A high pressure injection being
inoperable due to
1HP-24 (high pressure injection borated water storage tank suction isolation valve) the plant was in an orange risk condition. The licensee previously evaluated risk for an emergent condition associated with
1HP-24 and determined
1HP-24 was available and that the unit was in a yellow risk condition. The licensee recognized this omission later that day and entered the condition into their corrective action program as PIP-O-13-01822. The licensee also restored the reactor building spray train to its normal standby lineup. This finding was assessed using
IMC 0609, Phase 1 screening worksheet of Attachment 4 and Appendix K was determined to be of very low safety significance (Green), because the incremental core damage probability is less than
1E-6.
