A self revealed finding with a preliminary low to moderate safety significance and two associated apparent violations of
10 CFR Part 50, Appendix B, Criterion XVI, Corrective Actions, and Criterion III, Design Control, was self-revealed on August 9, 2011, due to the licenseei12s failure to prevent recurrence of a significant
condition adverse to quality. Specifically, on September 29, 2009,
coupling #7 on
service water pump P-7C failed due to
intergranular stress corrosion cracking (
IGSCC). The corrective actions taken to prevent recurrence did not consider all critical factors to prevent or minimize
IGSCC from recurring. On August 9, 2011,
coupling #6 on service pump P-7C failed due to
IGSCC. In addition, in 2007, when the licensee implemented a design change to the
coupling material, the licensee failed to reasonably address the factors to reduce susceptibility of the 416 stainless steel
couplings to
IGSCC. This issue was entered into the licenseei12s corrective action program (
CAP) as
CR-PLP-2011-03902. Long term corrective actions included replacing all
couplings in the three
service water pumps with
couplings made of a material that was less susceptible to
intergranular stress corrosion cracking. This finding was determined to be more than minor because the finding was associated with the
Initiating Events Cornerstone attribute of Design Control and affected the cornerstone objective of limiting the likelihood of those events that upset plant stability and challenge critical safety functions during power operation. Specifically, as a result of the performance deficiency, on August 9, 2011, pump P-7C failed during normal operation. The inspectors performed a Phase 1
SDP evaluation and determined that a Phase 2 evaluation was required because this finding contributed to both the likelihood of a
reactor trip and the likelihood that mitigation equipment or functions would not be available. The inspectors then performed a Phase 2 evaluation using the pre-solved
SDP worksheets for Palisades and determined that this finding screened as Yellow. Due to inherent conservatisms in the Phase 2 analysis, the RIII Senior Reactor Analysts performed a Phase 3
SDP analysis. The results of the Phase 3
SDP evaluation concluded that this finding was preliminarily determined to be White. The finding has a cross-cutting aspect in the area of Problem Identification and Resolution, Operating Experience, because the licensee failed to take into consideration significant operating
