05000280/LER-2012-001
| Docket Number02 01 12 2012 - 001 - 00 04 02 12 05000 | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2802012001R00 - NRC Website | |
1.0 DESCRIPTION OF THE EVENT On January 25, 2012, at 0033 hours3.819444e-4 days <br />0.00917 hours <br />5.456349e-5 weeks <br />1.25565e-5 months <br />, with Surry Power Station Units 1 and 2 at Charging (CH) pump [EllS:CB/BQ-P] 1B speed increaser gear box. The speed increaser and CH pump have a common lubrication system. The oil reservoir with sightglass is located in the speed increaser. Engineering noted that there was no increase in bearing temperature or vibration and concluded that the foaming was not detrimental to the operation of the pump. At 1630 hours0.0189 days <br />0.453 hours <br />0.0027 weeks <br />6.20215e-4 months <br />, Operations reported bearing flow from the bearings to the sump was normal; however, the gearbox sightglass was covered in foam. A gallon of oil was added with no visable change in oil level. The CH pump was secured and the oil level was observed to be above the top of the sightglass. At 2015 hours0.0233 days <br />0.56 hours <br />0.00333 weeks <br />7.667075e-4 months <br />, one half gallon of oil was drained from the speed increaser and the oil level was observed to be at approximately the midpoint of the sightglass. The oil was tested and no water or excessive wear particles were found. Testing also verified there was no degradation of anti-foaming agent. With adequate oil level and quality, no observed increase in bearing temperature, no increase in vibrations, and no aeration in the return, oil flow to the sump, CH pump 1B was considered operational and was placed in automatic. CH pump 1A remained the operating charging pump.
On January 31, 2012, at 1148 hours0.0133 days <br />0.319 hours <br />0.0019 weeks <br />4.36814e-4 months <br />, CH pump 1B was started and foaming was observed in the sightglass within 30 seconds. The foaming continued to increase and the pump was secured 3 minutes after the the pump was started. Based on the rate of foaming, it was concluded that air ingress on the oil pump suction line was the likely source of inleakage. On February 1, 2012, at 1410 hours0.0163 days <br />0.392 hours <br />0.00233 weeks <br />5.36505e-4 months <br />, CH pump 1B was declared inoperable and a plan was initiated to stop the air ingress. On February 2, 2012, at 0200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br />, oil pump suction line fittings were tightened and sealant was applied to the mechanical fittings. The oil was changed and the pump was started on February 4, 2012, at 0013 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> with no oil foaming observed.
Although foam was present in the oil for CH pump 1B, oil level was adequate with no leaks and no increase in bearing temperature or vibration trends. Also, the foaming was not considered excessive since none was coming out of any vents.
However, test data could not be provided to prove that the foaming would reach an equilibrium such that it would not continue foaming and deplete the oil to the point of threatening operation of the pump design basis mission time of 30 days.
Technical Specifications (TS) 3.2 and 3.3 require one flow path of charging to be in operation with an additional CH pump to be operable when the reactor is critical.
The TS limiting condition for operation (LCO) for one of the two CH pumps being inoperable is 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Without supporting information about the foaming, CH pump 1B was considered inoperable from January 25, 2012, when oil level could not be defined in the sightglass due to foaming, until the charging pump was declared inoperable on February 1, 2012, exceeding the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> LCO. Therefore,