05000454/FIN-2014005-01
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Finding | |
|---|---|
| Title | failure to Measure Interpass Temperature |
| Description | The inspectors identified a finding of very low safety significance and an associated NCV of 10 CFR Part 50, Appendix B, Criterion IX, Control of Special Processes, for a failure to measure the interpass temperature while performing welding on the on the safety injection (SI) piping system. Consequently, welding was performed without the Code and procedure required interpass temperature being monitored on a number of welds, a parameter which can affect the mechanical properties of the material being welded. After identification of the issue, the welders restored compliance by measuring the interpass temperatures on the balance of the welds and verifying that the interpass temperature did not exceed that allowed by procedure. The licensee entered this issue into its Corrective Action Program (CAP) (IR 02391545). The inspectors determined that this issue was more than minor in accordance wit
IMC 0612, Appendix B, Issue Screening, dated September 7, 2012, because the inspectors answered "Yes" to the More-than-Minor question, If left uncorrected, would the performance deficiency have the potential to lead to a more significant safety concern? Specifically, absent NRC intervention, the welders would have completed all of the welds without having measured the interpass temperature, a welding parameter which can affect the mechanical properties (e.g., impact properties) of some materials being welded, and if left uncorrected, could lead to a potential failure of the weld in service. In accordance with Table 2, Cornerstones Affected by Degraded Condition or Programmatic Weakness, of IMC 609, Attachment 4, Initial Characterization of Findings, issued June 19, 2012, the inspectors checked the box under the Mitigating Systems Cornerstone because leakage on the SI piping system could degrade short term heat removal. The inspectors determined this finding was of very-low safety significance (Green) using Part A of Exhibit 2, Mitigating Systems Screening Questions, in IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power, issued on June 19, 2012. Specifically, the inspectors answered "Yes" to the screening question If the finding is a deficiency affecting the design or qualification of a mitigating Systems Structures and Components (SSC), does the SSC maintain its operability or functionality? The welders proceeded to measure the interpass temperatures on the balance of the welds and verified that the interpass temperature did not exceed that allowed by procedure, and the issue did not result in the actual loss of the operability or functionality of a safety system. The finding had a cross-cutting aspect of Procedure Adherence in the area of Human Performance (IMC 0310 H.8). Specifically, the welders failed to follow procedures. |
| Site: | Byron  |
|---|---|
| Report | IR 05000454/2014005 Section 1R08 |
| Date counted | Dec 31, 2014 (2014Q4) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.08 |
| Inspectors (proximate) | C Thompson J Cassidy J Draper J Ellegood J Mcghee M Bielby M Holmberg R Baker R Jickling T Bilik |
| Violation of: | 10 CFR 50 Appendix B Criterion IX |
| CCA | H.8, Procedure Adherence |
| INPO aspect | WP.4 |
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Finding - Byron - IR 05000454/2014005 | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Byron) @ 2014Q4
Self-Identified List (Byron)
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