05000324/FIN-2012007-02
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Failure to Perform a Post Maintenance Test After Reactor Pressure Vessel Assembly |
| Description | A self-revealing (Green) non-cited violation (NCV) of 10 CFR 50, Appendix B Criterion V, Instructions, Procedures, and Drawings was identified for failure to properly implement plant procedure 0PLP-20, Post Maintenance Testing, after reactor pressure vessel (RPV) reassembly following the Unit 2 maintenance outage in November 2011. This resulted in the failure to identify improperly elongated RPV head studs, and contributed to excessive leakage from the Unit 2 RPV during reactor startup and pressurization on November 15 and November 16, 2011. The unit was shut down and depressurized on November 16, 2011, and the issue entered into the licensees CAP as NCR 500035. The licensees failure to comply with procedure 0PLP-20, Post Maintenance Testing, to ensure that a post maintenance test (PMT) was performed to verify that the RPV head was properly reassembled following the November 2011 Unit 2 maintenance outage was a performance deficiency. The finding was more than minor because it was associated with the Initiating Events cornerstone attribute of equipment performance (the reliability of the RCS barrier integrity) and adversely affected the cornerstone objective of limiting the likelihood of events that upset plant stability and challenge critical safety functions during shutdown or power operations. Specifically, the failure to perform a PMT after RPV reassembly contributed to excessive leakage from the Unit 2 RPV during reactor startup and pressurization. Inspection Manual Chapter 0609, Significance Determination Process (SDP), Attachment 0609.04, Phase 1 Screening Worksheet was used to screen the significance of the finding. The finding required a Phase 2 SDP analysis because it resulted in unidentified RCS leakage exceeding technical specification limits. Evaluation of the finding using the NRC pre-solved SDP table was not appropriate because the table does not contain a suitable target for RPV vessel integrity. Therefore, a Phase 3 SDP analysis was required. The regional Senior Reactor Analyst determined that failure to perform a post maintenance test would have had the potential to mitigate the failure to adequately torque the RPV head studs, which was analyzed to be a Green finding (see NCV 05000324/2012007-01 above). Since the impact of the mitigation would be less than the impact of the underlying finding, the failure to perform a post maintenance test is also a Green finding. The cause of this finding was directly related to the cross-cutting aspect of conservative assumptions in the decision making component of the Human Performance area because the licensee made nonconservative decisions regarding the need to perform a PMT following RPV assembly. |
| Site: | Brunswick  |
|---|---|
| Report | IR 05000324/2012007 Section 4OA5 |
| Date counted | Jun 30, 2012 (2012Q2) |
| Type: | NCV: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | |
| Inspectors (proximate) | R Musser |
| CCA | , |
| INPO aspect | DM.2 |
| ' | |
Finding - Brunswick - IR 05000324/2012007 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Brunswick) @ 2012Q2
Self-Identified List (Brunswick)
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||