ENS 53750
ENS Event | |
|---|---|
06:00 Nov 21, 2018 | |
| Title | En Revision Imported Date 12/31/2018 |
| Event Description | EN Revision Text: HPCI UNEXPECTEDLY TRANSFERRED TO ALTERNATE SUCTION SOURCE DURING TESTING
At 2125 [CST] on 11/21/2018, it was discovered that U1 High Pressure Coolant Injection System (HPCI) was inoperable; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v), as an event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. During performance of a routine surveillance, HPCI automatically transferred from its normal suction source to the alternate suction source. The control room operator then manually tripped the HPCI turbine. HPCI was already inoperable in accordance with Technical Specifications (TS) Limiting Condition for Operability (LCO) 3.5.1, ECCS Operating, Condition C during performance of the surveillance. However, this condition was not expected nor induced by the testing. There was no impact to the safety of the public or plant personnel. The NRC Resident Inspector has been notified. CR 1469109 documents this condition in the Corrective Action Program.
ENS Event Number 53750, made on November 22, 2018, is being retracted. NRC notification 53750 was made to ensure that the Eight-Hour Non-Emergency reporting requirements of 10 CFR 50.72(b)(3)(v)(D) were met when the licensee discovered an event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. During performance of a routine surveillance, the High Pressure Coolant Injection (HPCI) System automatically transferred from its normal suction source to the alternate suction source. As a result, Unit 1 HPCI was declared inoperable. On December 20, 2018, a Past Operability Evaluation was completed which determined that the HPCI System remained operable. The evaluation determined that the HPCI System could have performed its specified safety function of vessel injection throughout the time that the suction path was aligned to the torus. Therefore, this event is not reportable under 10 CFR 50.72(b)(3)(v)(D). TVA's evaluation of this event is documented in the Corrective Action Program in Condition Report 1469109. The licensee has notified the NRC Resident Inspector. Notified R2DO (Desai). |
| Where | |
|---|---|
Browns Ferry  Alabama (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+21.93 h0.914 days <br />0.131 weeks <br />0.03 months <br />) | |
| Opened: | Angel Yarbrough 03:56 Nov 22, 2018 |
| NRC Officer: | Dan Livermore |
| Last Updated: | Dec 28, 2018 |
| 53750 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (13 %) |
| After | Power Operation (13 %) |