ENS 48139
ENS Event | |
|---|---|
12:35 May 31, 2012 | |
| Title | 60-Day Optional Telephonic Notification for an Invalid Primary Containment Isolation Valve Actuation |
| Event Description | At 0535 [PDT] on 5/31/12 during power ascension following a maintenance outage, a loss of power to the Reactor Protection System (RPS) 'B' occurred due to the unexpected opening of the circuit breaker (RPS-CB-MG2) for the RPS 'B' motor generator. The loss of RPS 'B' resulted in a half scram signal, closure of Primary Containment Isolation Valves (PCIVs) from multiple systems and loss of power to main steam line radiation monitors (MS-RIS-610B & MS-RIS-610D). No plant parameters or maintenance activities existed which would cause the opening of RPS-CB-MG2; therefore, this is considered to be an invalid actuation of a system listed in 10CFR50.73(a)(2)(iv).
The half scram signal, closure of Primary Containment Isolation Valves (PCIVs) from multiple systems, and loss of power to MS-RIS-B & D were an expected response to the loss of RPS 'B'. Power ascension was temporarily halted. RPS 'B' was repowered from an alternate power supply. The half scram signal was reset, the containment isolation valves were opened and the affected systems were returned to normal operation. Power ascension was resumed. The circuit breaker (RPS-CB-MG2) was replaced and RPS 'B' was returned to its normal power supply. Initial investigation efforts have not determined a cause for RPS-CB-MG2 opening. Investigations into the cause of RPS-CB-MG2 opening are continuing. As indicated in 10CFR50.73(a)(1), in the case of an invalid actuation reported under 10CFR50.73(a)(2)(iv)(A), the licensee may, at its option, provide a telephonic notification to the NRC Operations Center within 60 days of discovery of the event instead of submitting a written LER. This 60-day telephone notification is being made to meet the reporting requirements instead of submitting an LER since the actuation was invalid. The following additional information is provided as specified in NUREG-1022: The specific train(s) and system(s) that were actuated: PCIVs in multiple systems EDR-V-19 Drywell Equipment Drain Inboard Isolation Valve EDR-V-20 Drywell Equipment Drain Outboard Isolation Valve FDR-V-3 Drywell Floor Drain Inboard Isolation Valve FDR-V-4 Drywell Floor Drain Outboard Isolation Valve RWCU-V-1 Reactor Water Cleanup Suction Inboard Isolation Valve RWCU-V-4 Reactor Water Cleanup Suction Outboard Isolation Valve RRC-V-19 Reactor Water Sample Inboard Isolation Valve RRC-V-20 Reactor Water Sample Outboard Isolation Valve TIP-V-15 Traversing In-Core Probe Purge Isolation Valve CRD-V-11 Control Rod Drive Scram Discharge Volume Drain Valve Whether each train actuation was complete or partial: All PCIVs actuations for a loss of RPS 'B' were complete The reactor half scram for a loss of RPS 'B' was a partial activation Whether or not the system started and functioned successfully: All PCIVs functioned successfully The licensee notified the NRC Resident Inspector. |
| Where | |
|---|---|
Columbia Generating Station  Washington (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1349.28 h56.22 days <br />8.031 weeks <br />1.848 months <br />) | |
| Opened: | Mot Hedges 17:52 Jul 26, 2012 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Jul 26, 2012 |
| 48139 - NRC Website
Loading map... {"minzoom":false,"maxzoom":false,"mappingservice":"leaflet","width":"350px","height":"250px","centre":false,"title":"","label":"","icon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"zoom":6,"defzoom":14,"layers":["OpenStreetMap"],"image layers":[],"overlays":[],"resizable":false,"fullscreen":false,"scrollwheelzoom":true,"cluster":false,"clustermaxzoom":20,"clusterzoomonclick":true,"clustermaxradius":80,"clusterspiderfy":true,"geojson":"","clicktarget":"","imageLayers":[],"locations":[{"text":"\u003Cb\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003E\u003Ca class=\"mw-selflink selflink\"\u003EENS 48139\u003C/a\u003E - \u003Ca href=\"/Columbia\" title=\"Columbia\"\u003EColumbia\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003E60-Day Optional Telephonic Notification for an Invalid Primary Containment Isolation Valve Actuation\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 48139 - Columbia\n","link":"","lat":46.55068333333333,"lon":-119.488975,"icon":"/w/images/7/7c/Energy_Northwest_icon.png"}],"imageoverlays":null} | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (86 %) |
| After | Power Operation (86 %) |
WEEKMONTHYEARENS 566252023-05-17T10:39:00017 May 2023 10:39:00
[Table view]10 CFR 50.73(a)(1), Submit an LER 60-DAY Optional Telephonic Notification for an Invalid Actuation of an Emergency AC Electrical Power System ENS 528692017-05-25T23:47:00025 May 2017 23:47:00 10 CFR 50.73(a)(1), Submit an LER Invalid High Pressure Core Spray (Hpcs) System Actuation in Mode 5 ENS 494602013-08-23T14:54:00023 August 2013 14:54:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for an Invalid Primary Containment Isolation Valve Actuation ENS 481392012-05-31T12:35:00031 May 2012 12:35:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for an Invalid Primary Containment Isolation Valve Actuation ENS 469772011-04-23T15:14:00023 April 2011 15:14:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System Actuation Due to Unrecognized Design Conflict ENS 469722011-04-21T20:10:00021 April 2011 20:10:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System Actuation Due to Conflicting Work Activities ENS 468972011-04-01T04:28:0001 April 2011 04:28:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Telephonic Notification of Invalid Specified System Actuation 2023-05-17T10:39:00 | |