ENS 44213
ENS Event | |
|---|---|
20:35 Mar 15, 2008 | |
| Title | Invalid Primary Containment Isolation System (Pcis) Actuation |
| Event Description | This 60-day telephone notification is being made under reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1).
On March 15, 2008, while resetting the main turbine in preparation for performing 1MST-RPS25R, 'RPS Turbine Stop Valve and Control Valve Closure Chan Cal,' a Group 1 isolation was received. Main Steam Lines (MSLs) A and B were isolated for local leak rate testing, however, the MSLs C and D were not. The inboard and outboard Main Steam Isolation Valves (MSIVs) for the C and D MSL closed as a result of this event. The isolation occurred during work associated with replacement of the main generator output breakers 22A and 22B. In order for the breakers to be removed, wiring that provides breaker position information was disconnected from the turbine control system (EHC). This resulted in a 'breaker closed' input to EHC. When the main turbine was reset, several logic interactions occurred resulting in the Group 1 isolation. No actual plant condition existed which required a Group 1 isolation and, with the Unit in Mode 4, Group 1 isolation is not required to be operable. Therefore, this actuation is considered to be invalid. The affected MSIVs and PCIS instrumentation operated properly. This was a full Group 1 isolation with only the MSIVs associated with the C and D MSLs closing since the A ad B lines were isolated when the actuation occurred. The invalid PCIS actuation was entered into the corrective action program (i.e., NCR 270475). The safety significance of this event was minimal. Plant equipment performed as expected. Group 1 isolation was not required to be operable in Mode 4. The Group 1 isolation was reset and a jumper was installed to prevent a subsequent invalid Group 1 isolation. Procedures will be developed or revised to disable the Group 1 Isolation during modes in which it is not required and to reset the main turbine during outages. The NRC Resident Inspector has been notified at this report. |
| Where | |
|---|---|
Brunswick  North Carolina (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| LER: | 05000324/LER-2008-001 |
| Time - Person (Reporting Time:+1432.68 h59.695 days <br />8.528 weeks <br />1.962 months <br />) | |
| Opened: | Lee Grzeck 13:16 May 14, 2008 |
| NRC Officer: | Jeff Rotton |
| Last Updated: | May 14, 2008 |
| 44213 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Cold Shutdown (0 %) |
| After | Cold Shutdown (0 %) |
WEEKMONTHYEARENS 569872024-01-02T04:33:0002 January 2024 04:33:00
[Table view]10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Containment Isolation Valves ENS 569882023-12-28T13:15:00028 December 2023 13:15:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Emergency Diesel Generators ENS 562872022-11-09T14:06:0009 November 2022 14:06:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Containment Isolation Valves ENS 561382022-08-06T10:28:0006 August 2022 10:28:00 10 CFR 50.73(a)(1), Submit an LER 60-DAY Optional Telephonic Notification of Invalid Actuation of Containment Isolation Valves ENS 558592022-03-07T04:40:0007 March 2022 04:40:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation 60-DAY Telephone Notification ENS 557562022-01-04T18:16:0004 January 2022 18:16:00 10 CFR 50.73(a)(1), Submit an LER 60-DAY Optional Telephonic Notification for Invalid Actuation of Containment Isolation Valves ENS 551912021-02-17T19:07:00017 February 2021 19:07:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Containment Isolation Valves ENS 546752020-03-05T14:25:0005 March 2020 14:25:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Telephonic Notification of an Invalid Specified System Actuation ENS 541442019-05-10T00:00:00010 May 2019 00:00:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Optional Notification Due to Actuation of an Emergency Diesel Generator ENS 527782017-04-06T16:12:0006 April 2017 16:12:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Emergency Diesel Generators ENS 520512016-05-09T10:26:0009 May 2016 10:26:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Primary Containment Isolation Valves (Pcivs) ENS 517392016-01-09T14:46:0009 January 2016 14:46:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Emergency Diesel Generator ENS 515052015-09-10T01:03:00010 September 2015 01:03:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of a General Containment Isolation Signal Affecting More than One System ENS 498002013-12-11T13:18:00011 December 2013 13:18:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Primary Containment Isolation System (Pcis) Valves During I&C Maintenance ENS 491682013-05-08T01:14:0008 May 2013 01:14:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Emergency Diesel Generators ENS 489722013-03-04T13:04:0004 March 2013 13:04:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Emergency Diesel Generators ENS 442132008-03-15T20:35:00015 March 2008 20:35:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System (Pcis) Actuation ENS 437912007-09-21T18:10:00021 September 2007 18:10:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Emergency Diesel Generators ENS 416922005-05-12T08:11:00012 May 2005 08:11:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.73(a)(1), Submit an LER Technical Specification Required Shutdown Due to Loss of Emergency Bus E1 ENS 413572004-12-13T21:15:00013 December 2004 21:15:00 10 CFR 50.73(a)(1), Submit an LER Invalid System Actuation ENS 405412004-01-11T11:37:00011 January 2004 11:37:00 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation ENS 404962003-12-22T03:04:00022 December 2003 03:04:00 10 CFR 50.73(a)(1), Submit an LER Invalid Reactor Building Exhaust Radiation Monitor Signal Resulting in Pcis Isolations 2024-01-02T04:33:00 | |