ENS 46656
ENS Event | |
|---|---|
21:15 Jan 3, 2011 | |
| Title | 60 Day Telephone Notificaton Concerning Invalid Containment Isolation System Actuations |
| Event Description | This 60-day telephone notification is being made under the reporting requirements specified by 10 CFR 50.73(a)(2)(iv) and 10 CFR 50. 73(a)(1) to report four closely-spaced invalid actuations of general containment isolation signals affecting more than one system.
Four events of unplanned actuations of general containment isolation signals affecting containment Isolation valves in more than one system occurred during planned transfers of power between the normal and alternate power supply for the 3A 480V Shutdown Board. The first event occurred on January 3, 2011, at 1515 hours0.0175 days <br />0.421 hours <br />0.0025 weeks <br />5.764575e-4 months <br /> Central Standard Time (CST), with Unit 3 in a forced outage and at 0 percent power (0 MWT). The electrical power to the 3A Reactor Protection System (RPS) was interrupted during the planned transfer of the 3A 480V Shutdown Board from its normal supply to its alternate power supply. During the transfer, the alternate feeder breaker did not close. An attempt was made to return to the normal power supply; however, the normal feeder breaker did not initially close but did close on re-attempt. This resulted in the interruption of power to the 3A 480V Shutdown Board, which caused the 3A RPS to de-energize, resulting in a half scram and the actuation of Primary Containment Isolation System (PCIS) logic Groups 2, 3, 6, and 8, and the initiation of Trains A, B, and C Standby Gas Treatment and Train A Control Room Emergency Ventilation. Plant conditions, which require PCIS actuations and the associated system initiations (e.g., low reactor water level, high drywell pressure, abnormal area radiation level, or high area temperature), did not exist; therefore, the actuation was invalid. The affected equipment responded as designed. On January 3, 2011, at approximately 1620 hours0.0188 days <br />0.45 hours <br />0.00268 weeks <br />6.1641e-4 months <br /> CST, Unit 3 Operations personnel restored 3A RPS power and re-aligned affected equipment, as appropriate. This event was entered in the Corrective Action Program as Problem Evaluation Report (PER) 305070. Subsequent related failure to transfer events of the 3A 480V Shutdown Board occurred on January 4, 2011, at 2321 hours0.0269 days <br />0.645 hours <br />0.00384 weeks <br />8.831405e-4 months <br />, on January 5, 2011, at 0448 hours0.00519 days <br />0.124 hours <br />7.407407e-4 weeks <br />1.70464e-4 months <br />, and on January 5, 2011, at 0841 hours0.00973 days <br />0.234 hours <br />0.00139 weeks <br />3.200005e-4 months <br />. In each event the plant conditions which require PCIS actuations and the associated system initiation did not exist; therefore, the actuations were invalid. In each of the three subsequent events the affected equipment started and functioned successfully with one exception. During the last event, Main Control Room indication of a Secondary Containment outboard isolation damper closure was indeterminate (i.e., double-lit). The damper was declared inoperable, and the associated Technical Specification LCO 3.6.4.2 Action was taken. [A} work order [was] issued to investigate the problem repaired a damper limit switch. This problem was entered in the Corrective Action Program as PER 305062. PERs were generated for each of these events (PER 305865, PER 305421, and PER 305893). All of these events were consolidated into PER 305070. The Browns Ferry NRC Senior Resident Inspector has been notified. |
| Where | |
|---|---|
Browns Ferry  Alabama (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1435.15 h59.798 days <br />8.543 weeks <br />1.966 months <br />) | |
| Opened: | Timothy Scott 16:24 Mar 4, 2011 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Mar 4, 2011 |
| 46656 - NRC Website
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WEEKMONTHYEARENS 556602021-10-20T13:05:00020 October 2021 13:05:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of a General Containment Isolation Signal Affecting More than One System ENS 552872021-04-01T18:02:0001 April 2021 18:02:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Telephonic Notification of Invalid Actuation of a General Containment Isolation Signal Affecting More than One System ENS 549322020-08-06T22:49:0006 August 2020 22:49:00 10 CFR 50.73(a)(1), Submit an LER | 60-Day Optional Telephonic Notification of an Invalid Actuation of a General Containment Isolation Signal Affecting More than One System ENS 549312020-08-06T06:28:0006 August 2020 06:28:00 10 CFR 50.73(a)(1), Submit an LER | 60-Day Optional Telephonic Notification of an Invalid Specified System Actuation ENS 547092020-03-16T06:02:00016 March 2020 06:02:00 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation ENS 546972020-03-09T01:21:0009 March 2020 01:21:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of a General Containment Isolation Signal Affecting More than One System ENS 543322019-08-20T16:33:00020 August 2019 16:33:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification of Invalid Specified System Actuation ENS 543002019-07-31T21:50:00031 July 2019 21:50:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification Due to an Invalid Actuation of a Containment Isolation Signal ENS 543412018-12-29T07:20:00029 December 2018 07:20:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of a Signal Affecting More than One System ENS 536612018-08-16T05:00:00016 August 2018 05:00:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of a General Containment Isolation Signal Affecting More than One System ENS 530702017-01-10T09:00:00010 January 2017 09:00:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of a General Containment Isolation Signal Affecting More than One System ENS 516282015-11-06T14:15:0006 November 2015 14:15:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of an Emergency Diesel Generator ENS 510852015-04-05T09:35:0005 April 2015 09:35:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for an Invalid Primary Containment Isolation System Actuation ENS 507542014-11-26T20:27:00026 November 2014 20:27:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of a General Containment Isolation Signal Affecting More than One System ENS 506582014-10-07T15:35:0007 October 2014 15:35:00 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation ENS 505652014-08-27T16:09:00027 August 2014 16:09:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of General Containment Isolation Signals ENS 499422014-01-21T13:46:00021 January 2014 13:46:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Optional Telephone Notification of an Invalid Primary Containment Isolation Signal ENS 490772013-04-09T10:06:0009 April 2013 10:06:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Report of an Invalid Primary Containment System Isolation Signal ENS 486902012-11-23T10:35:00023 November 2012 10:35:00 10 CFR 50.73(a)(1), Submit an LER Primary Containment Isolation Actuation Signal During Surveillance ENS 485872012-10-18T05:01:00018 October 2012 05:01:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Telephone Notification of an Invalid System Actuation ENS 485682012-10-09T16:50:0009 October 2012 16:50:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Telephonic Notification of an Invalid System Actuation ENS 485062012-09-18T06:45:00018 September 2012 06:45:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification of Invalid Actuation of Containment Isolation Signals ENS 485052012-09-17T09:12:00017 September 2012 09:12:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification of Invalid Actuation of Containment Isolation Signals ENS 480822012-05-19T05:06:00019 May 2012 05:06:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification of Invalid Specified System Actuation ENS 480062012-04-11T20:15:00011 April 2012 20:15:00 10 CFR 50.73(a)(1), Submit an LER Invalid System Actuation Resulting from Post Maintenance Testing ENS 474502011-09-19T16:00:00019 September 2011 16:00:00 10 CFR 50.73(a)(1), Submit an LER Invalid Group 6 Isolation Signal ENS 470032011-05-01T07:44:0001 May 2011 07:44:00 10 CFR 50.73(a)(1), Submit an LER Invalid Rps (Scram) Actuation ENS 468802011-03-30T19:43:00030 March 2011 19:43:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Telephonic Notification of Invalid Rps Signal Due to Loss of Variable Leg of Level Transmitter ENS 468812011-03-27T01:05:00027 March 2011 01:05:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Telephonic Notification of Invalid Primary Containment Isolation Signal Due to Maintenance ENS 466562011-01-03T21:15:0003 January 2011 21:15:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Telephone Notificaton Concerning Invalid Containment Isolation System Actuations ENS 460662010-07-02T17:32:0002 July 2010 17:32:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System Actuation from a Loss of Power to the Reactor Protection System (Rps) 3A ENS 460542010-04-30T21:48:00030 April 2010 21:48:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System (Pcis) Actuation from a Loss-Of-Power to Reactor Protection System (Rps) 1A ENS 460462010-04-27T22:37:00027 April 2010 22:37:00 10 CFR 50.73(a)(1), Submit an LER Invalid Group 6 Containment Isolation ENS 442942008-04-14T18:08:00014 April 2008 18:08:00 10 CFR 50.73(a)(1), Submit an LER Inadvertant Deenergization of Group Six Logic Circuit ENS 430832006-11-10T06:10:00010 November 2006 06:10:00 10 CFR 50.73(a)(1), Submit an LER Edg Actuation Due to Accidental Switch Mispositioning ENS 428782006-08-20T01:02:00020 August 2006 01:02:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System Actuation ENS 428772006-08-19T00:58:00019 August 2006 00:58:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System (Pcis) Actuation ENS 428672006-08-09T14:51:0009 August 2006 14:51:00 10 CFR 50.73(a)(1), Submit an LER Invalid Eecw Pump Actuation During Testing ENS 428372006-07-18T09:47:00018 July 2006 09:47:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System Actuation Due to Loss of Power to One Reactor Protection System Bus ENS 423892006-01-13T17:57:00013 January 2006 17:57:00 10 CFR 50.73(a)(1), Submit an LER Unplanned, Invalid Actuation of Emergency Diesel Generator ENS 422152005-11-15T14:05:00015 November 2005 14:05:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System (Pcis) Actuation ENS 411812004-09-28T18:02:00028 September 2004 18:02:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System Actuation from Loss-Of-Power to Reactor Protection System (Rps) Bus 2A ENS 411802004-09-25T23:14:00025 September 2004 23:14:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System Actuation from Loss-Of-Power to Reactor Protection System (Rps) Bus 3B 2021-04-01T18:02:00 [Table view] | |