ENS 53648
ENS Event | |
|---|---|
04:00 Oct 5, 2018 | |
| Title | Automatic Reactor Scram Due to Low Reactor Water Level |
| Event Description | On Friday, October 5, 2018 at 1209 hours0.014 days <br />0.336 hours <br />0.002 weeks <br />4.600245e-4 months <br />, with the reactor at 100 percent core thermal power, Pilgrim Nuclear Power
Station (PNPS) automatically tripped due to reactor water level perturbation and receipt of a low reactor water level Reactor Protection System (RPS) signal. The cause of the low reactor water level is under investigation. The plant is in hot shutdown. All other plant systems responded as designed. Pressure is being controlled using the Mechanical Hydraulic Control System and Main Condenser. Reactor water level is being maintained with the feedwater and condensate system. During the automatic reactor scram the plant experienced the following isolation signals as designed: Group 2 Isolation: Miscellaneous containment isolation valves Group 6 Isolation: Reactor Water Clean-up Reactor Building Isolation System Actuation Due to the RPS actuation while critical, this event is being reported as a four-hour, non-emergency notification in accordance with 10 CFR 50.72(b)(2)(iv)(B), 'any event that results in actuation of the reactor protection system (RPS) when the reactor is critical.' This notification is also being made in accordance with 10 CFR 50.72(b)(3)(iv)(A), 'Any event or condition that results in valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B) of this section ... ' (B)(2) 'General containment isolation signals affecting containment isolation valves in more than one system.' This event has no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The licensee will notify the Massachusetts Emergency Management Agency. |
| Where | |
|---|---|
| Pilgrim Massachusetts (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
| Time - Person (Reporting Time:+11.65 h0.485 days <br />0.0693 weeks <br />0.016 months <br />) | |
| Opened: | Kenneth Knell 15:39 Oct 5, 2018 |
| NRC Officer: | Dong Park |
| Last Updated: | Oct 5, 2018 |
| 53648 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | A/R |
| Before | Power Operation (100 %) |
| After | Hot Shutdown (0 %) |
Pilgrim with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
WEEKMONTHYEARENS 540712019-05-18T03:03:00018 May 2019 03:03:00
[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 Scram Due to Degrading Condenser Vacuum ENS 536482018-10-05T04:00:0005 October 2018 04:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram Due to Low Reactor Water Level ENS 531472018-01-04T19:10:0004 January 2018 19:10:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Scram Due to Partial Loss of Offsite Power During Winter Storm ENS 522232016-09-06T12:27:0006 September 2016 12:27:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Scram Due to High Reactor Water Level ENS 513382015-08-22T20:28:00022 August 2015 20:28:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Reactor Scram Due to a Single Msiv Closure ENS 510872015-05-22T14:02:00022 May 2015 14:02:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Loss of Condenser Vacuum ENS 507692015-01-27T09:02:00027 January 2015 09:02:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram on Turbine Trip Due to Loss of Offsite Power ENS 494542013-10-19T07:31:00019 October 2013 07:31:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Group 1 Isolation Due to High Reactor Water Level ENS 492962013-08-22T11:55:00022 August 2013 11:55:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Reactor Protection Actuation (Scram) ENS 489232013-04-15T02:17:00015 April 2013 02:17:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Specified System Actuations While Shutting Down ENS 487392013-02-10T19:05:00010 February 2013 19:05:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Loss of Offsite Power and Subsequent Press Release ENS 487362013-02-09T03:00:0009 February 2013 03:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared Due to Loss of Offsite Power ENS 486642013-01-10T20:34:00010 January 2013 20:34:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Reactor Protection Actuation (Scram) - Recirculation Pump Trip ENS 479452012-05-22T17:11:00022 May 2012 17:11:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Degrading Condenser Vacuum ENS 468372011-05-10T17:15:00010 May 2011 17:15:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Reactor Protection System Actuation During Start-Up ENS 466312011-02-20T15:34:00020 February 2011 15:34:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Reactor Protection System Actuation While Shutdown ENS 447372008-12-20T15:45:00020 December 2008 15:45:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Momentary Loss of 345Kv Offsite Power ENS 447352008-12-19T23:31:00019 December 2008 23:31:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram Due to Load Reject ENS 434792007-07-10T23:54:00010 July 2007 23:54:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Main Turbine Trip Causing a Reactor Scram ENS 432452007-03-17T20:58:00017 March 2007 20:58:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Group Isolations Following Manual Reactor Scram ENS 424142006-03-13T23:08:00013 March 2006 23:08:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Scram After Offgas System Failure 2019-05-18T03:03:00 | |