05000237/FIN-2010005-03
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Finding | |
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| Title | |
| Description | The inspectors identified an unresolved item regarding the operability of the Unit 2 drywell floor drain sump and drywell equipment drain sump inboard and outboard discharge air operated valves and their ability to perform their function as primary containment isolation valves. On October 19, 2010, the Unit 2 drywell floor drain sump (DWFDS) outboard discharge air operated valve (AOV), 2-2001-106, was declared inoperable due to local observation of a pinhole water leak between the body of the valve and the diaphragm while the valve was stroking closed after pumping the Unit 2 DWFDS. The licensee generated issue report (IR) 1127948, PCIV 2-2001-106 DWFDS DISCH VLV INOP, to address this issue. The licensee determined that the cause of the leak was relaxation of the valve bolting torque. Air operated valve 2-2001-106 was repaired by torquing the bolts back to the original torque value. In addition, the licensee generated operability evaluation (OpEval) number 10-007, Drywell Primary Containment Isolation System Equipment and Floor Drain Valves. The licensee determined that the leakage noted was not indicative of a diaphragm leak, which would originate from between the bonnet and diaphragm or the stem and bonnet of the valve. On October 27, 2010, the Unit 2 drywell equipment drain sump (DWEDS) pump inboard discharge air operated valve, 2-2001-5, and the Unit 2 drywell equipment drain sump pump outboard discharge air operated valve, 2-2001-6, exhibited pinhole leaks, 20 drops and 1 drop respectively, between the body of the valve and the lower side of the diaphragm while the valves were stroking closed after pumping the Unit 2 DWEDS. The licensee generated IR 1131662, DWEDS 2-2001-5 and 2-2001-6 BODY-DIAPHRAGM LEAKAGE, to address this issue. The licensee determined that based on OpEval 10-007, the leakage was not indicative of a diaphragm leak; therefore, valves 2-2001-5 and 2-2001-6 remained operable. As a compensatory action, the licensee performs weekly inspection of the valves during the pumping operation. By the end of the inspection period, both valves continued leaking and multiple IRs had been generated as a result of the weekly inspections performed. The inspectors questioned the licensee regarding the ability of these valves to meet the local leak rate test (LLRT) acceptance criteria and Technical Specification 3.6.1.3, Primary Containment Isolation Valves (PCIVs). The ability of the Unit 2 drywell equipment drain sump inboard and outboard discharge air operated valves to perform their function as primary containment isolation valves is considered an unresolved item pending further review of the licensees response. |
| Site: | Dresden  |
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| Report | IR 05000237/2010005 Section 1R15 |
| Date counted | Dec 31, 2010 (2010Q4) |
| Type: | URI: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | E Sanchez F Nestor R Jickling T Bilik D Melendez-Colon W Slawinski C Phillips M Ring T Go J Draper D Sandr Langstafft Briley T Go A Shaikh B Kemker C Phillips D Lords D Melendez Colon F Ramirez J Cameron J Corujo Sandin M Bielby P Smagacz R Jickling |
| INPO aspect | |
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Finding - Dresden - IR 05000237/2010005 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Dresden) @ 2010Q4
Self-Identified List (Dresden)
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