05000498/FIN-2011005-01
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Finding | |
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| Title | Seal Cap on Safety Injection System Hot Leg Check Valve |
| Description | In Condition Report 11-22991, during Refueling Outage 2RE15, the licensee identified reactor coolant system leakage from the valve seal cap enclosure on valve 1N122XSI0010A, when the licensee inspected this component. This inspection identified boric acid crystals on the insulation. When the insulation was removed, water and boron crystals were found inside the seal cap enclosure and on the valve bonnet. A weld defect (slag inclusion and porosity) was identified on the seal cap enclosure to bonnet seal weld, which was reworked in Refueling Outage 2RE15 per the ASME Section XI Program. This seal cap enclosure was originally installed in 1997 due to identified leakage from the body to bonnet gasket of check valve 1N122XSI0010A. On February 8, 1997, Condition Report 97-2156 documented steam coming from valve 1N122XSI0010A bonnet with boron buildup under the valve. The condition was identified while the system was at normal operating temperature and pressure, and was classified as a condition adverse to quality. The corrective action was to add a seal cap enclosure per the instructions of Work Package 336951 and the Westinghouse Vendor Technical Document VTD-W120-0652. However, the licensee stated in the design package that, The actual pressure boundary is still considered the gasket seating area of the body to bonnet and not the enclosure. Therefore, the enclosure is not a pressure retaining component as defined in ASME (code) for this application. In addition, the design package calculation V-EC-1655 had the following statement, The seal cap is considered a non-structural, non-pressure retaining attachment to the valve; therefore, it does not have to meet ASME Code allowables. This is because the pressure retaining function is still maintained by the main flange and its bolting. The material used must be identified and be compatible with the pressure retaining components. The licensee stated on numerous occasions that the design change did not shift the pressure boundary to the seal cap enclosure. When the licensee welded the seal cap enclosure around the valve body to bonnet gasket, it masked the leakage from the gasket. The licensee closed out Condition Report 97-2156 as completed, and the leakage from the body to bonnet joint on 1N122XSI0010A was no longer tracked in the corrective action program. The inspectors noted that the licensee documented leakage from the seal cap enclosure on multiple occasions between 1997 and 2011. These conditions were documented in Condition Reports 99-1108, 10-10120, and 11-22991. Despite repeated indications that there was an active boric acid leak from the pressure boundary, the leak from the bolted connection was not corrected, evaluated, or entered into the boric acid corrosion control program. The inspectors identified issues of concern with not correcting the degraded body-to-bonnet gasket as well as the inspection and/or corrective actions specified in accordance with the ASME Code. This issue was entered into the licensees corrective action program as Condition Report 11-23693, and will be treated as an unresolved item pending the review of additional information from the licensee and discussions with Headquarters personnel: URI 05000499/2011005-01, Seal Cap on Safety Injection System Hot Leg Check Valve. |
| Site: | South Texas  |
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| Report | IR 05000498/2011005 Section 1R08 |
| Date counted | Dec 31, 2011 (2011Q4) |
| Type: | URI: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.08 |
| Inspectors (proximate) | J Dixon B Tharakan W Walker J Laughlin N Hernandez J Wingebachl Carsons Garchow J Kramer J Watkins N Greene D Bradley J Dixon K Clayton B Tharakan |
| INPO aspect | |
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Finding - South Texas - IR 05000498/2011005 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (South Texas) @ 2011Q4
Self-Identified List (South Texas)
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