05000424/FIN-2012005-05
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Finding | |
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| Title | Licensee-Identified Violation |
| Description | On April 12, 2012, Vogtle staff identified that in-service inspections for the second 10- year ISI period were missed for eight ASME Code Class 1 valves. Valves 1/2 1208U6035, 1/2 1208U6036, 1/2 1208U6037 and 1/2 1208U6038 are chemical and volume control system normal and alternate charging check valves to the reactor coolant system. Leakage control devices (seal encapsulation devices) were installed on the Unit 1 valves in 1987 to address recurring body-to-bonnet leakage per an industry approved Westinghouse design change. The seal caps were subsequently installed on the unit 2 valves in 1989. Title 10 CFR 50.55a(g)(4) requires, in part, that licensees follow the pressure test requirements of ASME Code Section XI. ASME Code,Section XI, IWA- 5240, requires visual examinations as part of system pressure tests. ASME Code Section XI, IWA-5242, 1998 Edition through 2000 addenda, requires VT-2 visual examinations for pressure retaining bolted connections in borated water systems. Contrary to the above, from October, 1987, to the present, Vogtle did not perform a visual inspection of the valve body-to-bonnet studs. This finding was more than minor because it impacted the initiating events cornerstone and its attribute of equipment performance. Specifically, it affected the objective to limit the likelihood of those events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Using Inspection manual chapter 0609, dated June 19, 2012, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, this finding was determined to be of very low safety significance because the licensees evaluation was able to demonstrate structural integrity. Specifically, stud stress was not sufficiently close to the yield stress to cause a loss of integrity. Therefore, the finding does not contribute to both the likelihood of a reactor trip and the likelihood that mitigation equipment will not be available. The licensee has entered this issue into their corrective action program as CRs 438268, 458567, 505111 and 547078. To address the issue for the short term, the licensee plans to follow the needed and good practice recommendations detailed by the PWROG in letter OG-12-330 which was issued on August 16, 2012. The long term corrective actions will be to remove all of the existing seal caps and install a bonnet with a canopy seal weld to remove the need for a seal cap as a way to mitigate the effects of leakage and to allow visual examination of the bolted connections. |
| Site: | Vogtle  |
|---|---|
| Report | IR 05000424/2012005 Section 4OA7 |
| Date counted | Dec 31, 2012 (2012Q4) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | Licensee-identified |
| Inspection Procedure: | |
| Inspectors (proximate) | A Nielsen F Ehrhardt A Vargas-Mendez J Laughlin M Cain B Caballero T Chandler R Williams C Dykes W Pursley |
| INPO aspect | |
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Finding - Vogtle - IR 05000424/2012005 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Vogtle) @ 2012Q4
Self-Identified List (Vogtle)
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