ENS 45227
ENS Event | |
|---|---|
19:15 Jul 24, 2009 | |
| Title | Hpci Inoperable Due to Oil Leak in Mechanical Trip Hold Valve |
| Event Description | During performance of surveillance 1-SR-3.5.1.7, HPCI Main and Booster Pump Set Developed Head and Flow Rate Test at Rated Reactor Pressure, the HPCI Turbine Stop Valve Mechanical Trip Hold Valve, 1-PCV-73-18C, developed an oil leak of approximately 0.25 gpm. HPCI was INOPERABLE at the time of discovery due to performance of SR and continued to be INOPERABLE due to the oil leak that developed.
This event is reportable within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> in accordance with 10CFR 50.72(b)(3)(v) as an event or condition that at the time of discovery could have prevented the fulfillment of a safety function. It also requires a 60 day written report in accordance with 10CFR 50.73(a)(2)(vii). The licensee notified the NRC Resident Inspector.
On July 24, 2009, the High Pressure Coolant Injection (HPCI) Stop Valve Mechanical Trip Hold Valve (PCV-073-0018C) developed a ruptured diaphragm resulting an approximate 0.25 to 0.5 gallon per minute oil leak during scheduled performance of Surveillance Instruction, HPCI Main and Booster Pump Set Developed Head and Flow Rate at Rated Reactor Pressure. At the time BFN [Browns Ferry Nuclear] made [event] notification 45227, there were concerns regarding the ability of HPCI to fulfill its safety function, hence, BFN made an eight hour notification in accordance with 10CFR50.72(b)(3)(v)(B) and 10CFR50.72(b)(3)(v)(D). An evaluation performed in response to this notification concluded that the HPCI System was capable of performing its intended safety function with the oil leak. TVA Engineering evaluated the rate of oil loss considering a worse case failure of PCV-073-0018C diaphragm and determined that the turbine oil system capacity is such that the oil loss thru the failed diaphragm would not impact HPCI operation during its mission time for the Design Basis accidents and transients for which HPCI is credited. The circumstances discussed in the notification did not result in any condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or system that are needed to remove residual heat and mitigate the consequences of an accident. Therefore, this event is not reportable under 10CFR50.72(b)(3)(v)(B) and 10CFR50.72(b)(3)(v)(D). TVA documented the evaluation of this event notification in its corrective action program (PER 177206). The licensee has notified the NRC Resident Inspector. Notified R2DO (Rudisail). |
| Where | |
|---|---|
Browns Ferry  Alabama (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+-0.42 h-0.0175 days <br />-0.0025 weeks <br />-5.75316e-4 months <br />) | |
| Opened: | Timothy D. Boland 18:50 Jul 24, 2009 |
| NRC Officer: | Donald Norwood |
| Last Updated: | Sep 22, 2009 |
| 45227 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |