ENS Event | |
|---|---|
13:25 Sep 8, 2020 | |
| Title | Automatic Reactor Trip on Over Power Delta Temperature |
| Event Description | At 0925 EDT, on September 8, 2020, with Unit 1 in Mode 1 at 100 percent power, the reactor automatically tripped on Overpower Delta Temperature. Unit 1 Channel 1 Overpower Delta Temperature was tripped as a planned evolution when an inadvertent Unit 1 Channel 2 Overpower Delta Temperature signal was received. This resulted in an automatic reactor trip. The trip was not complex, with all systems responding normally. Because of the reactor trip, the Auxiliary Feedwater (AFW) System actuated as expected due to on ATWS Mitigation System Actuation Circuitry (AMSAC) signal. Unit 2 is not affected.
Operations responded and stabilized the plant. Decay heat is being removed by discharging steam to the main condenser using the condenser steam dump valves. Due to the Reactor Protection System (RPS) actuation while critical, this event is being reported as a 4-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). This event is also being reported as an 8-hour non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the AFW system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| Where | |
|---|---|
Catawba  South Carolina (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation | |
| Time - Person (Reporting Time:+-0.2 h-0.00833 days <br />-0.00119 weeks <br />-2.7396e-4 months <br />) | |
| Opened: | Walter Hunnicutt 13:13 Sep 8, 2020 |
| NRC Officer: | Jeffrey Whited |
| Last Updated: | Sep 8, 2020 |
| 54888 - NRC Website | |
WEEKMONTHYEARENS 561772022-10-24T12:57:00024 October 2022 12:57:00
[Table view]10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip and Auxiliary Feedwater System Actuation ENS 558562022-04-23T06:24:00023 April 2022 06:24:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip During Control Rod Testing ENS 548882020-09-08T13:25:0008 September 2020 13:25:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Trip on Over Power Delta Temperature ENS 545232020-02-12T23:00:00012 February 2020 23:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram Due to Main Turbine Trip ENS 412462004-12-06T02:35:0006 December 2004 02:35:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Turbine Trip/Reactor Trip Due to Moisture Separator Reheater (Msr) High Level Trip Signal. ENS 411542004-10-28T04:52:00028 October 2004 04:52:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip After Shutdown Bank Dropped Into Core ENS 405382004-02-22T22:30:00022 February 2004 22:30:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unit 1 Manually Tripped After the "B" Sg Feedwater Isolation Valve Failed Closed ENS 401142003-08-29T06:03:00029 August 2003 06:03:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Catawba Unit 1 Automatic Reactor Trip Due to Reactor Protection System Actuation 2022-04-23T06:24:00 | |