05000289/FIN-2011005-01
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Finding | |
|---|---|
| Title | Inspect and Disposition Leakage Event from BRCP Flange from 1R19 |
| Description | During a plant shutdown on October 24,2011, Exelon BACC inspectors did not inspect the flanged, gasketed joints of RCP thermal barrier flanges of RC-P-1A, RC-P-18, RC-P-1C and RC-P-1D, while the plant was at hot shutdown conditions. The affected joints use flexitalic gaskets to seal the thermal barrier housing to the RCP motor and to the RCP volute. Exelon inspected the RCP flanges on October 11,2011, after an Exelon NDE inspector observed a significant amount of boric acid on the flange of RCP RC-P-18 and on the pump\\\'s discharge piping inside containment. However, when this inspection was performed on November 1, 2011, the RCS was cold, depressurized and drained. Thus, the inspection conditions did not meet those specified in ER-AP-331-1001, Rev. 5, step 4.1.4.2., to complete A walkdown inspection of borated systems/components inside containment shall be performed to identify evidence of boric acid leakage as soon after plant shutdown . . . as practical, at each refueling. Because this inspection was not completed at operating pressure as specified, Exelon had missed an opportunity to determine the actual leak rate of the component because the RCS was drained and depressurized when the leakage evidence was discovered, i.e. the plant was no longer at hot shutdown conditions. Upon inspection on November 1, 2011, at cold shutdown, Exelon attributed the significant leakage to a damaged flange gasket, an equipment failure. Subsequent examination of the affected carbon steel flange bolts identified degradation of one of the flange bolts. The inspectors reviewed Exelon\\\'s evaluation of the bolt for continued use. Exelon had identified the presence of the boric acid residue coming from the B RCP flange on November 1, 2011, and placed the condition into the corrective action process. However, the inspectors noted that because the B RCP and associated piping had been drained and depressurized, when inspected, Exelon had missed an opportunity to fully characterize, or measure the actual leak rate. Exelon subsequently provided the NRC additional information and an understanding of past Exelon BACC practices at TMl. To completely resolve this issue, the inspectors need additional information from the licensee to evaluate the issue against the current licensing basis and determine if the apparent performance deficiency is more than minor. |
| Site: | Three Mile Island  |
|---|---|
| Report | IR 05000289/2011005 Section 1R08 |
| Date counted | Dec 31, 2011 (2011Q4) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.08 |
| Inspectors (proximate) | T Moslak D Werkheiser G Hunegs C Cahill C Crisden J Heinly D Everhart M Orr B Cookc Cahilld Kern D Werkheiser G Hunegs J Heinly J Richmond K Cronk R Nimitz S Barr T O'Hara |
| INPO aspect | |
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Finding - Three Mile Island - IR 05000289/2011005 | |||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Three Mile Island) @ 2011Q4
Self-Identified List (Three Mile Island)
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