ENS 54983
ENS Event | |
|---|---|
03:50 Nov 5, 2020 | |
| Title | |
| Event Description | At 2150 CST on 11/04/2020, it was discovered that Unit 1 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 1-SR-3.5.1.7, HPCI Main and Booster Pump Set Developed Head and Flow Rate Test at Rated Reactor Pressure, Unit 1 HPCI was manually tripped by the control room operator due to local report of excessive shaking of the cooling water supply from the booster pump line. There was no impact to the safety of the public or plant personnel. The NRC Resident Inspector has been notified. CR 1650042 documents this condition in the Corrective Action Program. The Unit is in a 14-day LCO 3.5.1(c). The RCIC System is operable.
ENS Event number 54983, made on 11/05/2020 is being retracted. NRC notification 54983 was made to ensure that the Eight-Hour Non-Emergency reporting requirements of 10 CFR 50.72 were met when Unit 1 HPCI was manually tripped by the control room operator due to a local report for excessive shaking of the cooling water supply from the booster pump line. A subsequent engineering evaluation concluded on 11/06/2020 there was reasonable assurance of operability with no additional intrusive maintenance performed and that the condition was bounded by a previous evaluation documented in [Condition Report] CR 1347736. As such, the circumstances discussed in the report did not result in any condition that at the time of discovery could have prevented the fulfillment of the safety function of structures of the system that are needed to mitigate the consequences of an accident. Therefore, this event is not reportable under 10 CFR 50.72(b)(3)(v). TVA's evaluation of this event is documented in the corrective action program. The licensee has notified the NRC Resident Inspector. Notified R2DO (Miller). |
| 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:+2.7 h0.113 days <br />0.0161 weeks <br />0.0037 months <br />) | |
| Opened: | Michael Millsap 06:32 Nov 5, 2020 |
| NRC Officer: | Bethany Cecere |
| Last Updated: | Dec 29, 2020 |
| 54983 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (17 %) |
| After | Power Operation (16 %) |