ENS 46268
ENS Event | |
|---|---|
12:30 Sep 22, 2010 | |
| Title | |
| Event Description | At 0830 [EDT] on 09/22/2010, the Unit 2 High Pressure Coolant Injection (HPCI) system was determined to be inoperable due to a minor lube oil leak on the 'A' supply filter. LCO 3.5.1 for the HPCI system was entered at 0830 [EDT] on 09/22/2010.
The leak on the 'A' filter could not be immediately corrected. The 'B' filter was placed in service and leak checked satisfactorily. The LCO 3.5.1 action statements were closed at 1454 [EDT] on 09/22/2010. This incident is being reported as an event or condition that could have prevented fulfillment of a safety function required to mitigate the consequences of an accident in accordance with 10CFR50.72(b)(3)(v)(D). The licensee notified the NRC Resident Inspector.
At 1501 on September 22, 2010, PPL Susquehanna, LLC reported that the Unit 2 High Pressure Coolant Injection (HPCI) system was inoperable due to a minor lube oil leak on the 'A' supply filter. Subsequent investigation and evaluation determined that HPCI was capable of performing all of its safety functions with the identified oil leak. The operability determination was based on the following: Investigation of the leak identified that the installed filter housing cover o-ring was undersized and had to be inappropriately stretched to fit in the o-ring groove in the housing cover. The cover is torqued to 75 ft-lbs by four bolts on the outer diameter of the cover, enclosing the o-ring in a metal to metal connection. There is no concern for the o-ring to extrude from the cover under this configuration. The worst case that can be postulated as a result of the undersized o-ring is a leak in which the drops break into a small stream. This type of leak is expected to result in less than 10 gallons of oil loss during the system's 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> mission time. The vendor recommended oil reserve level is approximately 124 gallons. The lube oil sump has a 155 gallon capacity and the remaining oil (approximately 145 gallons) is sufficient to support operability. As a result, the worst case leakage is not expected to affect operability of HPCI or result in system failure during the HPCI mission time. Operations verifies oil level weekly and prior to any planned run. The licensee has notified the NRC Resident Inspector. Notified R1DO (Gray). |
| Where | |
|---|---|
Susquehanna  Pennsylvania (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+2.65 h0.11 days <br />0.0158 weeks <br />0.00363 months <br />) | |
| Opened: | Dave Borger 15:09 Sep 22, 2010 |
| NRC Officer: | Vince Klco |
| Last Updated: | Nov 18, 2010 |
| 46268 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (94 %) |
| After | Power Operation (94 %) |