ENS 49296
ENS Event | |
|---|---|
11:55 Aug 22, 2013 | |
| Title | Reactor Protection Actuation (Scram) |
| Event Description | On Thursday, August 22, 2013 at 0755 hours0.00874 days <br />0.21 hours <br />0.00125 weeks <br />2.872775e-4 months <br /> [EDT], with the reactor critical at approximately 98% core thermal power, and the mode switch in RUN, a manual reactor scram was inserted due to lowering reactor water level. The cause of the lowering reactor water level was due to the trip of all three Feedwater Pumps. The cause of the Feedwater Pump trip event is currently under investigation.
Following the reactor scram, all control rods were verified to be fully inserted. All 4kV busses transferred to the Startup Transformer as designed. Following the scram the reactor water level lowered to +12 inches initiating the Primary Containment Isolation System (Group II, Reactor Building Isolation System (RBIS); and Group VI - Reactor Water Cleanup System) automatically as per design. Reactor water level lowered to -46 inches initiating Primary Containment Isolation System Group I - Main Steam Isolation Valves (MSIVs); Emergency Core Cooling Systems (ECCS) actuated which included automatic start and injection of the High Pressure Coolant Injection (HPCI) System and the Reactor Core Isolation Cooling (RCIC) System and an automatic start of the Emergency Diesel Generators as designed. Reactor water level was promptly restored to normal level. Currently a cooldown is in progress with reactor pressure is being maintained by the HPCI System operating in the pressure control mode and reactor water level is being maintained by the RCIC System. Reactor Water Clean-up System and normal reactor building ventilation have been restored. Off-site power is being supplied to the station by the Start-up Transformer (normal power supply for shutdown operations). This event had no impact on the health and/or safety of the public. The USNRC Senior Resident Inspector has been notified. This 4-hour notification is being made in accordance with 10 CFR 50.72 (b)(2)(iv)(A) and (B). The plant is transferring from decay heat removal to the torus to decay heat removal to the main condenser. Reactor pressure is 371 psig. Initial indications are that a main feedwater power supply breaker tripped. |
| Where | |
|---|---|
| Pilgrim Massachusetts (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
| LER: | 05000293/LER-2013-008 |
| Time - Person (Reporting Time:+-0.27 h-0.0113 days <br />-0.00161 weeks <br />-3.69846e-4 months <br />) | |
| Opened: | Robert Oneill 11:39 Aug 22, 2013 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Aug 22, 2013 |
| 49296 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | Yes, Manual Scram |
| Before | Power Operation (98 %) |
| 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, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge | |
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 | |