05000255/FIN-2007007-06
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Finding | |
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| Description | On September 17, 2007 the licensee performed test RT-8C, Engineered Safeguards System - Left Channel. This test is done every cycle to load the diesel and sequence loads in accordance with plant design. The inspectors watched the diesel start automatically and load from the control room as part of the surveillance baseline inspection. The inspectors then went down to the 1-1 EDG and during a walkdown noted fuel dripping from the bottom of the fuel pump cover for cylinder 1R. The leak rate was five drops per second. The inspectors brought the issue to the licensees attention. The licensee briefly removed the cover and discovered two screws present at the bottom of the cover and a much higher leakrate (on the order of hundreds of milliliters per minute) of fuel oil. The screws were from the mechanical joint between the fuel rail and the low pressure fuel line on the 1R cylinder. After discussion between Engineering and Operations, the 1-1 EDG was shutdown and the test terminated. The licensee wrote CR-PLP-2007-04078 to address the issue. They discovered the screws in question should have been torqued. The licensee repaired the connection with new screws and torqued all similar connections on other cylinders on the 1-1 EDG. The test was completed satisfactory. The licensee also torqued the screws for the 1-2 EDG. The licensee performed an apparent cause for the CR in question. The apparent cause concluded that there was inadequate preventative maintenance to ensure the fuel oil header to fuel pump connection remained tight. The 1R screws were not torqued when last known to be tightened in 1994, but were tightened evenly until metal-to-metal contact was made. The licensee noted there were opportunities to address the issue from internal and external operating experience. In 2001 a CR was written (C-PAL-01-03293) when a cylinder on the 1-2 EDG had the screws over-torqued. The action was to use new screws and tighten the screws to the value provided by the vendor of 25 ft-lb. Hitherto, no torque value was specified by the vendor manual or procedure. The procedure change request was generated to update the vendor manual and maintenance procedure with new specifications from the vendor to 25-27 ft-lb. The vendor manual update was not accomplished, nor was a corrective action put in place to torque the existing screws. In 2002 another procedure change request was submitted to add these torquing requirements to the EDG maintenance procedure during maintenance which discovered there was torquing deficiencies on an adjacent bolt (C-PAL-02-02053). This was accomplished, but no corrective actions were put in place to torque the existing screws on the cylinders. In May of 2003 the 1L cylinder of the 1-1 EDG had a fuel oil leak on an adjacent joint to the joint in question on 1R. WO 24320418 was accomplished which removed, then reinstalled, the fuel oil header to fuel pump connection, then torqued the screws off the fuel header to 25 ft-lb. In March of 2007, an Operating Experience (OE) from another plant was received which noted a fuel leak from the same cylinder (1R) and identical bolts due to the bolts not being torqued correctly. The item was screened by the OE group and no OE review was assigned. The system engineer entered the OE as action request (AR) 01082056, but it was not screened as an adverse condition to quality by the corrective action screening team, and was designated as a non-CAP. A non-CAP action, Other Action (OTHA) 01082056-01, was scheduled for review in July, but was extended until after the outage in November. The inspectors concluded that the failure to take corrective action to torque the screws from the fuel oil header to the fuel pump to a value specified by the vendor was within the licensees ability to foresee and correct and is therefore a performance deficiency. Because this deficiency could have an impact on the EDG ability to adequately deliver fuel to the cylinders required in an accident, and because this condition may have existed (in some state where the bolts could loosen) for some time, the issue may be more than minor. This item will remain an URI (URI 05000255/2007007-06, 1-1 EDG Fuel Header Leak) until the licensee completes its past operability assessment and the NRC reviews this assessment. There is no current safety issue, as all screws have been torqued to the required value. |
| Site: | Palisades  |
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| Report | IR 05000255/2007007 Section 4OA5 |
| Date counted | Dec 31, 2007 (2007Q4) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | |
| Inspectors (proximate) | J Cassidy D Jones J Ellegood S Bakhsh R Telson J Giessner M Learn N Adornop Lougheedj Jandovitz B Jose J Cassidy J Lennartz J Ellegood J Bartleman J Giessner C Lipa K Streit |
| INPO aspect | |
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Finding - Palisades - IR 05000255/2007007 | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Palisades) @ 2007Q4
Self-Identified List (Palisades)
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