The inspector identified a non-cited violation of
10 CFR 50.55a(g)(4) for the licensee's failure to evaluate an
ASME code class piping leak in the Unit 1 spent fuel pool piping, or perform evaluation prior to returning the system to service. A
through wall leak in the piping of the spent fuel pool cooling system downstream of valve
SFP 23, spent fuel pool to the cask loading pit isolation valve, was identified in August 2009. The licensee closed Condition Report CR-ANO-1-2009-1521, and Work Order
WO 03771, after completing clean-up of the
boric acid cyrstals. As of May 23, 2014, the exact location, size, and geometry of the flaw were still unknown. The section of piping containing the flaw was isolated and tagged out of service. This issue was documented in Conditio
Report CR-ANO-C-2014-1801. The inspector determined that the licensees failure to follow the ASME Code requirements for evaluating the leak in the Unit 1 spent fuel pool cooling system was a performance deficiency. The finding was more than minor in accordance with Inspection Manual Chapter 0612, Appendix B, Issue Screening, because it was associated with the barrier integrity cornerstone attribute of design control and adversely affected the structural integrity of the spent fuel pooling cooling system. Specifically, the licensee failed to appropriately evaluate a through wall flaw in the piping in the spent fuel pool cooling system in accordance with the requirements of ASME Code,Section XI, to ensure structural integrity of the piping. The inspectors evaluated the finding using Inspection Manual Chapter 0609, Significance Determination Process, Attachment 0609.04, Initial Characterization of Findings, Tables 2 and 3, dated June 19, 2012, and Appendix A, The Significance Determination Process (SDP) for Findings At-Power, Exhibit 3, Part D, for the spent fuel pool, dated June 19, 2012. The inspector determined the finding to be of very low safety significance (Green) because the finding did not cause the pool temperature to exceed the maximum analyzed temperature limit; it did not cause mechanical damage to fuel clad and a detectible release of radionuclides; it did not result in a loss of spent fuel pool water inventory below the minimum analyzed level limit; and it did not affect the spent fuel pool neutron absorber, fuel bundle misplacement or soluble boron concentration
The finding had a cross-cutting aspect in the area of human performance, resources
because the licensee failed to ensure personnel and procedures were adequate to support nuclear safety. Specifically, the licensee failed to ensure personnel and procedures were available and adequate to recognize the regulatory requirement to evaluate components in
ASME Code systems that do not comply with Code requirements [H.1]. (Section 1R08)
