ENS 47644
ENS Event | |
|---|---|
23:19 Feb 6, 2012 | |
| Title | Manual Rps Actuation Due to Turbine Trip |
| Event Description | Unit 2 had been connected to the grid at 1431 CST today following a recent forced outage and was in the process of power ascension in accordance with plant procedures. At approximately 25% reactor power (approximately 240 MWe), the operators were transferring main feed flow to the steam generator lower nozzle through the feedwater isolation valves, (i.e. 2FW009A, B, C, D).
2FW009C was the first valve to be opened due to previously experienced problems with this valve being stuck in the seat. No issues were experienced during the opening of 2FW009C. Upon opening of 2FW009C, the 2C steam generator level began to rise as expected. The operators throttled back feedwater flow to control steam generator level. However, the 2C steam generator level increased to the High-High level setpoint of 80.8% (p-14). Since the reactor was below 30% (P-8), no automatic reactor trip signal was generated. However, the turbine automatically tripped, a feedwater isolation signal was initiated, and 2C Main Feedwater pump trip occurred as designed. With no main feedwater flow available, the operators manually tripped the reactor and entry into procedure 2BEP 0, Reactor Trip or Safety Injection Unit 2 was entered. The operators then manually started the 2A and 2B Auxiliary Feedwater pumps to supply water to the steam generators prior to reaching the Low-Low steam generator level setpoint of 36.3%. Transition from 2BEP 0 to 2BEP ES-0.1, Reactor Trip Response, was completed and the emergency procedures were exited. Unit 2 is being maintained in a stable condition in Mode 3. The NRC Resident Inspector has been informed. |
| Where | |
|---|---|
Byron  Illinois (NRC Region 3) | |
| 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:+-2.65 h-0.11 days <br />-0.0158 weeks <br />-0.00363 months <br />) | |
| Opened: | Jim Lynde 20:40 Feb 6, 2012 |
| NRC Officer: | Charles Teal |
| Last Updated: | Feb 6, 2012 |
| 47644 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | Yes, Manual Scram |
| Before | Power Operation (25 %) |
| After | Hot Standby (0 %) |
Byron with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
WEEKMONTHYEARENS 540202019-04-22T18:24:00022 April 2019 18:24:00
[Table view]10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Initiation of the Auxiliary Feedwater System in Response to a Loss of Feedwater ENS 534912018-07-06T05:00:0006 July 2018 05:00:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Transformer Failure Causes Loss of Offsite Power to Unit 2 ENS 522952016-10-12T18:38:00012 October 2016 18:38:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Due to Spurious Feedwater Isolation ENS 508592015-03-03T17:01:0003 March 2015 17:01:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Main Power Transformer Bushing Short ENS 499192014-03-15T16:02:00015 March 2014 16:02:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Momentary Loss of Shutdown Cooling Due to a Loss of Offsite Power ENS 488382013-03-21T00:51:00021 March 2013 00:51:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Trip Due to Loss of Generator Stator Cooling Water ENS 477082012-02-28T23:31:00028 February 2012 23:31:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unusual Event Due to Loss of Offsite Power ENS 476442012-02-06T23:19:0006 February 2012 23:19:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Rps Actuation Due to Turbine Trip ENS 476242012-01-30T16:01:00030 January 2012 16:01:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Unusual Event Due to Loss of Offsite Power Greater than 15 Minutes ENS 458672010-04-19T10:03:00019 April 2010 10:03:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Rps and Afw Actuation Signals While Shutdown in Mode 4 ENS 420632005-10-19T05:57:00019 October 2005 05:57:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Trip Due to Low 2 Steam Generator Water Level 2019-04-22T18:24:00 | |