05000280/LER-2005-003
| Telephone Number (Include Area Code) | |
| Event date: | 06-11-2005 |
|---|---|
| Report date: | 10-6-2005 |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident |
| 2802005003R00 - NRC Website | |
1.0 DESCRIPTION OF THE EVENT On August 11, 2005, with Units 1 and 2 operating at 100% reactor power, the results of the monthly engine oil sample for Emergency Service Water Pump (ESWP) 1B [EllS—BI, ENG] indicated fuel contamination of the engine oil in the marginal range. Evaluation of previous monthly oil analyses revealed that although the results remained within the acceptable range, an increasing trend of fuel contamination began with the June 11, 2005 sample. The rate of fuel intrusion was such that the ESWP could not sustain long-term operation. Engine oil viscosity also exhibited a concurrent, declining trend but remained within the acceptable range as well. Based on this evaluation, ESWP 1B was declared inoperable on August 11, 2005 at 1900 hours0.022 days <br />0.528 hours <br />0.00314 weeks <br />7.2295e-4 months <br />.
Subsequent inspection and pressure test of the fuel system found a leak at the connection between the fuel supply jumper and the #1L fuel injector. The fuel injector and jumper were replaced, the fuel system was pressure tested satisfactorily, and the engine oil was changed.
ESWP 1B was declared operable on August 17, 2005 following a successful return to service operational test.
Technical Specification (TS) 3.14.A.4 requires that the reactor coolant system not exceed 350°F or 450 psig or that the reactor shall not be critical unless three ESWPs are operable.
This requirement may be modified to have two ESWPs operable for a period not to exceed 7 days. ESWP 1B was assumed to be inoperable beginning June 11, 2005 and remained inoperable until completion of testing on August 17, 2005, exceeding the allowed outage time of 7 days. Therefore, this report is being submitted pursuant to 10CFR50.73(a)(2)(i)(B), any operation or condition that was prohibited by the plant's TS. In addition, during the period when the 1B pump was assumed to be inoperable, a second ESWP was taken out of service to perform maintenance or modifications. The long-term service water requirement for a design basis accident on one unit and the service water requirement to bring the other unit to Hot Shutdown are greater than the design capacity of one ESWP. Therefore, this report is also being submitted pursuant to 10CFR50.73(a)(2)(v)(D), any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident.
2.0 SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS Each ESWP has a design capacity of 15,000 gallon per minute (GPM). The long-term service water requirements for a design basis accident in one unit with a simultaneous loss of-station power and the second unit being brought to Hot Shutdown is greater than 15,000 gpm. Additional service water is required to bring the non-accident unit to Cold Shutdown.
Considering a single active failure of one pump, TS require three ESWPs to be operable to ensure sufficient cooling water is available in the event of an accident. One ESWP is permitted to be inoperable for up to a 7-day period to provide operational flexibility for testing or maintenance without requiring unit outages.
viscosity was a leak at the connection between the fuel inlet line and the 1L injector. The root cause for the leak was a failure to identify and correct a defect at the seating area on the inlet of the 1L injector where the flared end of the fuel line seats. This defect was a flat spot that extends through the entire flared fitting seating surface. When initially installed, the connection did not leak, as indicated by the fuel system pressure test and the engine oil analysis. However, over time due to vibration, heat-up and cool-down this fitting began to leak.
4.0 IMMEDIATE CORRECTIVE ACTION(S1 An inspection and pressure test of the fuel system for ESWP 1B was conducted. During this inspection a leak was identified at the flared connection between the jumper and the inlet side of the #1L fuel injector. The fuel injector and jumper were replaced, all other fuel system mechanical joints were tightened, the engine oil was changed, and a satisfactory fuel system pressure test as well as a successful return to service test run was performed.
5.0 ADDITIONAL CORRECTIVE ACTIONS An engine oil sample was obtained after the return to service test. The results of the analysis for fuel contamination of the engine oil and for oil viscosity were acceptable. The oil analysis results for the September sample were also acceptable.
The engine oil analysis results from the two other ESWP diesels, the three Station Emergency diesels, the Station Blackout diesel, and the Security diesel were reviewed for fuel contamination of the engine oil and for oil viscosity. The review concluded that the results were consistent and within acceptable ranges.
NRC Fonn 366A (1-2001) injector. Engine oil testing for fuel contamination was initiated. Also, a visual inspection for fuel leaks during engine operation following maintenance was initiated. No additional issues for fuel contamination of engine oil were identified.
8.0 MANUFACTURER/MODEL NUMBER Detroit Diesel Model 8V71 9.0 ADDITIONAL INFORMATION None