05000313/FIN-2007005-05
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Finding | |
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| Title | Apparent Inadequate Procedure for Containment Air Lock Leakage Testing |
| Description | On December 4, 2007, the licensee conducted leakage testing of the Unit 2 containment escape air lock barrel per Procedure 2304.258, Unit 2 Escape Airlock Leak Rate Test, Revision 016. The maintenance workers were unable to pressurize the air lock barrel to accident pressure per Step 8.3.10 of the procedure. Technicians at the scene noted excessive air leakage through the containment air lock outer door seals. Since the air lock inner door had passed a LLRT the previous week and had not been operated since, operators concluded the leakage through the outer door seals was the cause of the failure of the air lock barrel to pressurize. Operators declared the surveillance test invalid since accident pressure could not be achieved in the escape air lock barrel. The inspectors determined that the operators declaration of the test as an invalid test lacked a technical basis. The inspectors noted the purpose of the leakage test was to detect leakage from the air lock. Since the air lock barrel could not be pressurized due to excessive leakage through the outer door, the inspectors concluded the surveillance test therefore demonstrated a valid failure of the air lock outer door seals. Although the operators did not recognize the test results as a failed surveillance test, they kept the air lock inner door locked closed, meeting the TS actions required for an inoperable air lock outer door. On December 5, 2007, the licensee performed an LLRT on the Unit 2 containment escape hatch outer door seals. The door seals passed the LLRT with only minimal leakage. Despite the test result, the licensee replaced the outer door seals since technicians had reported excessive leakage through the seals during the air lock barrel test. Licensee engineers concluded the outer door seals passed the test as a result of differences in the LLRT and air lock barrel testing procedures. The team determined that additional information was required to determine the acceptability of the licensees method for leak testing the air lock door seals. Additional information was needed to determine whether there was a violation of 10 CFR Part 50, Appendix J, requirements or the station containment LLRT program. Pending further review of additional information provided by the licensee, this issue is being treated as an URI 05000368/2007005-05, Apparent Inadequate Procedure for Containment Air Lock Leakage Testing. |
| Site: | Arkansas Nuclear  |
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| Report | IR 05000313/2007005 Section 1R22 |
| Date counted | Dec 31, 2007 (2007Q4) |
| Type: | URI: |
| cornerstone | No Cornerstone |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.22 |
| Inspectors (proximate) | D Bollock G Miller J Clark J Josey P Elkmann R Egli C Youngj Clarkc Young B Rice A Sanchez G Miller J Josey |
| INPO aspect | |
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Finding - Arkansas Nuclear - IR 05000313/2007005 | |||||||||||||||||||||
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Finding List (Arkansas Nuclear) @ 2007Q4
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