05000455/FIN-2013005-06
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Finding | |
|---|---|
| Title | Corrosion Effects on the Unit 2 Reactor Vessel Not Monitored |
| Description | The inspectors identified a finding of very low safety significance and an associated NCV of 10 CFR 50, Appendix B, Criterion XI, ?Test Control,? when licensee personnel failed to establish a program to monitor the corrosion effects on the reactor vessel flange integrity caused by the ingress of borated water below abandoned head stud number 11. The licensee entered this issue into their CAP as IR 01578289, ?EC [Engineering Change] 379850 Failed to Adequately Evaluate Boron Corrosion.? The inspectors determined that the performance deficiency was more than minor because it was associated with the Design Control attribute of the Initiating Events cornerstone and adversely affected the cornerstone objective of limiting the likelihood of those events that upset plant stability and challenge critical safety functions. The inspectors also answered ?Yes? to the more-than-minor screening question, ?If left uncorrected, would the performance deficiency have the potential to lead to a more significant safety concern?? Specifically, the inspectors determined that this issue was more than minor because, if left uncorrected, the failure to adequately evaluate the long-term corrosion effects on reactor vessel flange integrity could result in a LOCA. The inspectors performed a Phase 1 SDP Screening and evaluated this issue by application of Questions 1 and 2. Questions 1 and 2 asked: ?If after a reasonable assessment of degradation, could the finding result in exceeding the reactor coolant leak rate for a small LOCA or could the finding have likely affected other systems used to mitigate a LOCA resulting in a total loss of their function (e.g., Interfacing System LOCA)?? In this case, the degradation had not yet progressed to the point that would impact reactor vessel flange integrity, so the inspectors answered these questions ?No? and this issue screened as having very low safety significance. This finding had a cross-cutting aspect in the CAP component of the Problem Identification and Resolution cross-cutting area because the licensee did not take appropriate corrective actions to address safety issues and adverse trends in a timely manner, commensurate with their safety significance and complexity. Specifically, the licensee failed to develop a procedure for monitoring the boric acid corrosion induced wastage of the reactor vessel head flange as a corrective action resulting from a review of EC 379850 |
| Site: | Byron  |
|---|---|
| Report | IR 05000455/2013005 Section 1R18 |
| Date counted | Dec 31, 2013 (2013Q4) |
| Type: | NCV: Green |
| cornerstone | Initiating Events |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.18 |
| Inspectors (proximate) | C Thompson D Jones E Duncan J Cassidy J Laughlin J Mcghee J Robbins M Holmberg M Jones N Feliz _Adorno R Ng S Sheldon B Bartlett B Palag |
| Violation of: | 10 CFR 50 Appendix B Criterion XI |
| CCA | P.3, Resolution |
| INPO aspect | PI.3 |
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Finding - Byron - IR 05000455/2013005 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Byron) @ 2013Q4
Self-Identified List (Byron)
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