05000348/FIN-2009004-01
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Finding | |
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| Title | Failure to Implement Performance Monitoring of Service Water Pump Seismic Supports |
| Description | The NRC identified an issue of concern regarding the licensees failure to monitor the condition of the Unit 1 and Unit 2 SW pump seismic rings. The failure to implement measures to monitor the material condition of the seismic rings resulted in component degradation to the extent that the 2E SW pump was unable to perform its safety function in response to a design basis seismic event. This issue of concern will be characterized as an unresolved item (URI) pending further inspection by the NRC to determine both (1) the extent of condition for this issue (i.e. if a performance deficiency exists) and (2) the degree to which the reliability of plant equipment was adversely impacted as a result of the failure to monitor the affected components (i.e. more than minor). On August 2, 2009 during a performance run of the 2E SW pump, the licensee noticed abnormal noise in the wet pit area of the service water intake structure (SWIS) in the vicinity of the 2E SW pump. The control room operators declared the pump inoperable. The licensee inspected the 2E SW pump seismic ring remotely and determined the ring had dropped approximately 5 inches at its most remote point from the SWIS wall. The seismic ring is a hoop encircling the pumps discharge column allowing approximately 0.200 inch clearance with the discharge column. The hoop is bolted onto a bracket which is bolted to the SWIS vertical wall inside the wet pit. Divers entered the SWIS wet pit on August 14, 2009 and confirmed the indications seen on the remote camera. On August 15, 2009, the divers torqued the upper bolts of the wall bracket and replaced two bolts connecting the hoop of the seismic ring to the wall bracket. This activity restored the seismic ring to the required location. The divers performed ultra-sonic measurements of the wall bracket and discovered evidence of corrosion at multiple locations. The most excessive corrosion observed was located in the lower right portion of the bracket and resulted in the lower right corner of the bracket corroding so the bolt hole and corner was missing from approximately 35 percent of the circumference. Other locations did not have sufficient corrosion to adversely affect the structural integrity of the wall bracket. The two lower bolts for the wall bracket were corroded to the extent that their fasteners and most of the bolt threads were missing. These bolts were not replaced. The licensee performed an operability determination for the as-left condition of the seismic ring and declared the pump operable for this condition on August 15, 2009. The inspectors did not identify an immediate safety concern for this issue because the licensee had taken corrective actions to repair the 2E SW pump seismic ring following discovery of the issue. Additionally, the licensee implemented interim compensatory measures to maximize the availability of potentially affected SW pumps pending completion of diver inspections that would determine the material condition of the remaining SW pump seismic rings. The inspectors determined that in order to appropriately evaluate and disposition this issue of concern, additional inspection would be required to better understand: (1) the extent of condition associated with this issue (supported by the completion of diver inspections that were in progress at the end of the inspection period), and (2) the degree to which the reliability of plant equipment may have been adversely impacted as a result of the failure to monitor the affected components. This issue of concern was identified as URI 05000348,364/2009004-01 Failure to Implement Performance Monitoring of Service Water Pump Seismic Supports. |
| Site: | Farley  |
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| Report | IR 05000348/2009004 Section 1R12 |
| Date counted | Sep 30, 2009 (2009Q3) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.12 |
| Inspectors (proximate) | A Nielsen D Jones E Crowe G Kuzo H Gepford L Miller R Moore S Sandal S Shaefferb Desai B Sherbin C Even C Peabody D Jones J Eargle P Braxton R Moore R Patterson S Kobylarze Crowe S Shaeffer W Rogers G Macdonald B Caballero S Sandal |
| INPO aspect | |
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Finding - Farley - IR 05000348/2009004 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Farley) @ 2009Q3
Self-Identified List (Farley)
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