ENS 48204
ENS Event | |
|---|---|
03:49 Jun 19, 2012 | |
| Title | Invalid Actuation of Containment Ventilation Isolation |
| Event Description | Watts Bar Nuclear Plant's (WBN's) containment ventilation isolation systems provide the means of isolating ventilation systems that pass through containment penetrations to confine to the containment any radioactivity that may be released following a design basis event. The containment ventilation system isolates following a manual or automatic safety injection signal, high containment purge exhaust radiation levels, or manual actuation.
On 6/18/12 at 2349 EDT, a B train containment ventilation isolation signal was received in the Main Control Room due to an invalid high radiation signal from a containment purge exhaust radiation monitor (1-RM-131). Corrective action replaced the 1-RM-131 ratemeter following the 6/18/12 B train containment ventilation isolation. However, on 7/2/12 at 1252 EDT, a second B train containment ventilation isolation signal was received in the Main Control Room due to another invalid high radiation signal from 1-RM-131. An investigation found that 1-RM-131 was spiking repeatedly due to a defective Power On indicating light socket which affected the 120 VAC power circuit that is common with the 24 volt power supply. 120 VAC signal fluctuations could affect the 24 volt power supply signal to the rate meter causing output spikes. Corrective action replaced the defective Power On indicating light socket on 7/3/12. This event notification is being made in accordance with 10 CFR 50.73(a)(2)(iv)(A) as a 60 day telephone notification of the invalid initiation of a containment isolation signal. The specific system and train that was actuated was B train containment ventilation isolation. The system functioned as designed and the complete train operated. WBN's NRC Resident Inspector has been notified. |
| Where | |
|---|---|
Watts Bar  Tennessee (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1426.37 h59.432 days <br />8.49 weeks <br />1.954 months <br />) | |
| Opened: | Michael Bottorff 14:11 Aug 17, 2012 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Aug 17, 2012 |
| 48204 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 562742022-11-24T21:21:00024 November 2022 21:21:00
[Table view]10 CFR 50.73(a)(1), Submit an LER 60-DAY Optional Telephonic Notification of Invalid Actuation of Containment Ventilation Isolation Valves ENS 548702020-07-23T13:56:00023 July 2020 13:56:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for Two Invalid Containment Ventilation Isolation Actuations ENS 542202019-07-26T14:03:00026 July 2019 14:03:00 10 CFR 50.73(a)(1), Submit an LER Invalid Containment Ventilation Isolation Actuation ENS 538402018-12-02T05:28:0002 December 2018 05:28:00 10 CFR 50.73(a)(1), Submit an LER Invalid Containment Ventilation Isolation Actuation ENS 527902017-04-28T09:00:00028 April 2017 09:00:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for an Invalid Auxiliary Feedwater Actuation ENS 525392016-12-15T18:32:00015 December 2016 18:32:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Optional Telephonic Notification for an Invalid Containment Ventilation Isolation Actuation ENS 520012016-04-14T18:06:00014 April 2016 18:06:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for an Invalid Containment Vent Isolation Actuation ENS 511522015-04-15T16:07:00015 April 2015 16:07:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuations of the Containment Ventilation Isolation System ENS 510792015-03-17T17:06:00017 March 2015 17:06:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Auxiliary Feedwater System During Electrical Testing ENS 501332014-04-16T05:48:00016 April 2014 05:48:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for Inadvertent Fast Start of Diesel Generator During Testing ENS 482042012-06-19T03:49:00019 June 2012 03:49:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Containment Ventilation Isolation ENS 441602008-02-23T04:00:00023 February 2008 04:00:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Verbal Notification of Invalid Specified System Actuation ENS 411832004-09-15T14:14:00015 September 2004 14:14:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Containment Vent Isolation Valve 2022-11-24T21:21:00 | |