05000266/LER-2009-001
| Docket Number | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2662009001R00 - NRC Website | |
During the period from 1/1/09 to 1/5/09, small oil additions to the inboard bearing oiler and sight glass tubing assembly [EllS= 38] of component cooling water (CCW) pump [EllS= P], 1P-011B, were required on three (3) occasions. Throughout this period, the pump remained in service. The oil additions were not documented in the corrective action program (CAP). At 1410 on 1/5/09, the pump was declared out of service (OOS) and Technical Specification Action Condition (TSAC) 3.7.7.A was entered for maintenance.
At 2124 hours0.0246 days <br />0.59 hours <br />0.00351 weeks <br />8.08182e-4 months <br /> on 1/5/09, satisfactory post-maintenance testing was completed and the pump was returned to service.
Between 1/5/09 to 1/27/09, operators conducting rounds each shift verified proper pump operation. There were no entries of oil leakage documented in the narrative logs.
At 1031 hours0.0119 days <br />0.286 hours <br />0.0017 weeks <br />3.922955e-4 months <br /> on 1/27/09, oil was added to the inboard bearing oiler. The addition was documented in the CAP for trending purposes only. At 1539 hours0.0178 days <br />0.428 hours <br />0.00254 weeks <br />5.855895e-4 months <br /> on 1/31/09, operators determined that another oil addition to the inboard bearing oiler was required. At that time, the pump was declared OOS and TSAC 3.7.7.A was entered for maintenance. The oil addition was entered into the CAP. At 1908 hours0.0221 days <br />0.53 hours <br />0.00315 weeks <br />7.25994e-4 months <br /> on 1/31/09, the pump was returned to service. At 0831 on 2/1/09, operators again discovered that oil needed to be added to the inboard bearing oiler. The pump was declared OOS and TSAC 3.7.7.A was entered. The condition was entered into the CAP. At 0043 hours4.976852e-4 days <br />0.0119 hours <br />7.109788e-5 weeks <br />1.63615e-5 months <br /> on 2/4/09, satisfactory post-maintenance testing was completed on the pump and the pump was returned to service.
The CCW system removes residual and sensible heat from the reactor coolant system in support of long-term cooling following a loss of coolant accident (LOCA). Plant safety analyses credit the CCW system for 30 days of continuous operation during the post-LOCA, residual heat removal recirculation phase.
Plant procedures require refilling the pump inboard bearing oiler whenever the oil bubbler drops below one-third (1/3) level. During the period from 1/1/09 to 1/5/09, the pump inboard bearing oiler required refill on three (3) occasions. During the period from 1/27/09 to 1/31/09, the pump inboard bearing oiler required refill on two (2) occasions. A maximum allowable oil leak rate is not specifically defined in plant design bases documents and threshold oil leakage criterion for pump operability had not been established prior to the subject periods.
Based upon the quantity and frequency of oil refills during the periods of oil leakage, past operability evaluations completed in March 2009 determined that the estimated time for depletion of the pump inboard bearing oil would occur before CCW Pump 1P-11B would have completed its 30-day mission time.
When the cumulative time of inoperability was considered, it was concluded that the pump was inoperable in excess of the 72-hour Technical Specification (TS) allowable Completion Time and is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) as, "...an operation or condition that was prohibited by the plant's Technical Specifications.
S. ...� The cause of the event was the failure to document oil additions to 1P-11B into the corrective action program (CAP) and a failure to perform an adequate operability review as a result of the oil leakage problems.
D. EXTENT OF CONDITION
An extent of condition review was performed with the following conclusions reached:
- Operations procedures need to be revised to assure that small oil leaks on safety-related pumps are evaluated for their potential impact on pump operability.
- Maintenance procedures .for safety-related pumps need to be revised to incorporate vendor and industry operating experience and to provide a greater level of detail.
E. ASSESSMENT OF SAFETY CONSEQUENCES
The plant response during and following the periods of oil leakage was as expected and Unit 1 was maintained in a safe, controlled condition at all times. Prior to securing CCW pump 1P-11B, 1P-11A was started and required CCW flow to safety related equipment was maintained at all times. Therefore, CCW system availability was not challenged by this event. Online risk assessments performed when CCW pump 1P-11(3 was inoperable were green during the periods of oil leakage. Accordingly, this event is of low safety significance.
F, CORRECTIVE ACTIONS The following corrective actions have been identified as a result of the causal evaluations performed:
Completed Corrective Actions:
1. CCW pump i1P-11B was declared 00S for oil leakage concerns and actions were taken to repair the pump under a plant maintenance work order.
2. Expectations have been reiterated in Operations regarding the sensitivity of oil additions to safety related pumps and actions to be taken when problems are identified.
I*■1RC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (9-2007) Corrective Actions currently tracked in the Corrective Action Program.
1. Establish a tracking process for oil additions to safety-related pumps.
2. Add precautions and limitations to plant operating instructions stating that small oil leaks can cause pump inoperability to ensure that knowledge of this event is not lost.
3. Revise affected maintenance procedures to incorporate vendor and industry operating experience and to provide a greater level of detail.
G. ADDITIONAL INFORMATION
None
H. SIMILAR EVENTS
None