ENS 52172
ENS Event | |
---|---|
14:15 Aug 11, 2016 | |
Title | Control Room Emergency Ventilation System Declared Inoperable |
Event Description | At 1015 [EDT] on August 11, 2016, it was discovered that a Fire Protection damper associated with the Control Room Emergency Ventilation System had closed unexpectedly due to component failure. The closure rendered both trains of the Control Room Emergency Ventilation System (CREVS) inoperable requiring both Unit 1 and 2 to enter Technical Specification Limiting Condition of Operation (LCO) 3.7.10 Condition G. Condition G requires immediate entry into LCO 3.0.3. At 1159 on August 11, 2016, actions were taken to block the deficient damper in the open position restoring both trains of CREVS to a fully operable condition and allowing exit of LCO 3.0.3 and 3.7.10 Condition G.
The purpose of CREVS is to provide a protected environment from which occupants can control the [respective] unit following an uncontrolled release of radioactivity, hazardous chemicals, or smoke. In the event of a design basis accident, emergency ventilation components realign to supply filtered air and to pressurize the Control Room Envelop (CRE). While the damper was closed both trains of CREVS were incapable of supplying the Relay Room as well as the Technical Support Center and its associated support spaces. These locations constitute part of the CRE, therefore both trains of CREVS were inoperable. Both trains of CREVS being inoperable affected the habitability of the TSC where the assessment capability of the facility for all emergencies was adversely effected. The NRC Resident Inspector has been notified. |
Where | |
---|---|
Sequoyah ![]() Tennessee (NRC Region 2) | |
Reporting | |
10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | |
Time - Person (Reporting Time:+2.33 h0.0971 days <br />0.0139 weeks <br />0.00319 months <br />) | |
Opened: | Timothy M. Wood 16:35 Aug 11, 2016 |
NRC Officer: | Dong Park |
Last Updated: | Aug 11, 2016 |
52172 - 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 52172\u003C/a\u003E - \u003Ca href=\"/Sequoyah\" title=\"Sequoyah\"\u003ESequoyah\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EControl Room Emergency Ventilation System Declared Inoperable\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 52172 - Sequoyah\n","link":"","lat":35.22651944444444,"lon":-85.09192777777778,"icon":"/w/images/c/ce/Tennessee_Valley_Authority_icon.png"}],"imageoverlays":null} | |
Unit 1 | |
---|---|
Reactor critical | Critical |
Scram | No |
Before | Power Operation (100 %) |
After | Power Operation (100 %) |
Unit 2 | |
---|---|
Reactor critical | Critical |
Scram | No |
Before | Power Operation (100 %) |
After | Power Operation (100 %) |