ENS 45981
ENS Event | |
|---|---|
23:15 Apr 16, 2010 | |
| Title | Invalid Specified System Actuation |
| Event Description | Invalid actuation of ECCS for boiling water reactors (BWRs) including: high-pressure and low-pressure core spray systems; high pressure coolant injection system; low pressure injection function of the residual heat removal system.
The following information is provided as a 60 day telephone notification to NRC under 10 CFR 50.73(a)(1) in lieu of submitting a written LER to report a condition that resulted in an invalid actuation of the 10CFR50.73(a)(2)(iv)(B) system checked above. NUREG1022 Revision 2 identifies the information that needs to be reported as discussed below. This report is being made under 10CFR50.73(a)(2)(iv)(A). On April 16, 2010, at 1717 EDT, Unit 1 received a false ECCS (Emergency Core Cooling System) Loss Of Cooling Accident (LOCA) signal on high drywell pressure. Based on plant data, all plant conditions were normal prior to event. Investigation identified an ATTS Slave Card failed in one of the Card File Racks. The Card File Rack contains ten (10) cards with two (2) being Master Trip Units (MTUs) that actuate on high drywell pressure. For initiation of an ECCS LOCA signal, both of the MTUs in the card file rack would have had to actuate. Cause of the event appears to be a momentary drop in supply voltage on the card file rack due to the failed slave card that lowered the set point of the MTUs to a point where they tripped. The set point is an internal voltage setting within the MTU. The failed ATTS cards have been replaced. Actuations: Core Spray A and B pumps started; Residual Heat Removal A, B, C, D pumps started; Diesel Generator 1A, 1B, and 1C started; Standby Plant Service Water Pump started; Plant Service Water 1A pump started (it had been in standby); Plant Service Water Valves 1P41-F310A, B, C, D closed (These are the Turbine Building isolation valves); Turbine Building Chiller B tripped; Main Control Room Environmental Control trains A and B started; HPCI Started but was secured prior to injection; Cooling Tower fans on towers A, B, C tripped. Reactor Water Level was normal at +37 inches and the highest Drywell Pressure indicated was 1.25 psig. The licensee has notified the NRC Resident Inspector. |
| Where | |
|---|---|
Hatch  Georgia (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1235.8 h51.492 days <br />7.356 weeks <br />1.693 months <br />) | |
| Opened: | Bill Duvall 11:03 Jun 7, 2010 |
| NRC Officer: | Dong Park |
| Last Updated: | Jun 7, 2010 |
| 45981 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (86 %) |
WEEKMONTHYEARENS 568972023-11-02T01:11:0002 November 2023 01:11:00
[Table view]10 CFR 50.73(a)(1), Submit an LER 60 Day Notification for an Invalid Specified System Actuation ENS 551882021-02-18T03:20:00018 February 2021 03:20:00 10 CFR 50.73(a)(1), Submit an LER Automatic Actuation of Group 2 Containment Isolation Logic ENS 551872021-02-13T03:23:00013 February 2021 03:23:00 10 CFR 50.73(a)(1), Submit an LER Automatic Actuation of Group I Containment Isolation Logic ENS 538172018-11-12T05:00:00012 November 2018 05:00:00 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation ENS 528182017-04-27T04:29:00027 April 2017 04:29:00 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation Due to Failed Relay ENS 528032017-04-17T15:20:00017 April 2017 15:20:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification of Invalid Specified System Actuation ENS 526852017-02-17T15:21:00017 February 2017 15:21:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification of Invalid Specified System Actuation ENS 496412013-10-21T09:19:00021 October 2013 09:19:00 10 CFR 50.73(a)(1), Submit an LER 60 Optional Report - Invalid Partial Reactor Protection System Actuation ENS 490552013-03-24T14:09:00024 March 2013 14:09:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Hpci Suction Valves ENS 487212012-12-08T06:16:0008 December 2012 06:16:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephone Notification of Invalid System Actuation ENS 485652012-10-08T22:09:0008 October 2012 22:09:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification of Invalid System Actuation ENS 483702012-08-06T01:25:0006 August 2012 01:25:00 10 CFR 50.73(a)(1), Submit an LER Rps Sub-Component Failure Caused Half Scram with Group 2 Pciv Actuation ENS 478592012-02-25T05:38:00025 February 2012 05:38:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Standby Gas Treatment Secondary Containment Isolation Valves (Scivs) ENS 473372011-08-12T09:03:00012 August 2011 09:03:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Optional Telephone Notification for an Invalid Specified System Actuation ENS 461152010-05-29T12:49:00029 May 2010 12:49:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Primary Containment Isolation Valves Due to a Faulty Transistor ENS 459812010-04-16T23:15:00016 April 2010 23:15:00 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation ENS 458352010-02-23T14:50:00023 February 2010 14:50:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Standby Gas Treatment System ENS 432762007-02-25T08:58:00025 February 2007 08:58:00 10 CFR 50.73(a)(1), Submit an LER Invalid Secondary Containment Isolation ENS 424922006-02-28T06:50:00028 February 2006 06:50:00 10 CFR 50.73(a)(1), Submit an LER Invalid System Actuation Due to Work Instruction Error ENS 421102005-10-07T15:37:0007 October 2005 15:37:00 10 CFR 50.73(a)(1), Submit an LER Invalid System Actuation ENS 415902005-02-19T10:50:00019 February 2005 10:50:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Invalid Actuation of System Report. 2023-11-02T01:11:00 | |