ENS 41997: Difference between revisions

v t e ENS Event
16:29 Sep 17, 2005
Title	Reactor Scram Due to Maintenance
Event Description	On 09/17/2005 at 1129 CDT, Browns Ferry Unit 3 reactor automatically scrammed due to the trip of the main generator turbine on low main condenser vacuum. Prior to the trip, the unit was operating at reduced power (74 percent) and maintenance was in progress to repair in place a secondary plant moisture separator level control valve. This maintenance activity resulted in the low condenser vacuum condition. Plant response to the scram was as expected. Post-scram transient RPV low water level caused a valid automatic initiation of primary containment isolation (PCIS) valves group 2 (containment sumps and shutdown cooling valves), group 3 (reactor water cleanup system), group 6 (ventilation systems, including initiation of standby gas treatment and control room emergency ventilation systems), and group 8 (traversing in-core probe system). This event is reportable to the NRC via ENS within four hours under 10CFR50.72(b)(2)(iv)(B) (RPS actuation while critical), and within eight hours under 10CFR50.72(b)(3)(iv)(A) (RPS and containment isolation actuation). Browns Ferry Unit 2 was not affected. The reactor shutdown and all control rods fully inserted. Condenser vacuum has been restored and decay heat is being removed using the bypass valves.

ENS 41997 +/-
Where
Browns Ferry Alabama (NRC Region 2)
Reporting

10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation
Time - Person (Reporting Time:+-0.37 h-0.0154 days <br />-0.0022 weeks <br />-5.06826e-4 months <br />)
Opened:	Mike Morrow 16:07 Sep 17, 2005
NRC Officer:	Bill Gott
Last Updated:	Sep 17, 2005
41997 - 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 41997\u003C/a\u003E - \u003Ca href=\"/Browns_Ferry\" title=\"Browns Ferry\"\u003EBrowns Ferry\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EReactor Scram Due to Maintenance\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 41997 - Browns Ferry\n","link":"","lat":34.70418333333333,"lon":-87.11844722222222,"icon":"/w/images/c/ce/Tennessee_Valley_Authority_icon.png"}],"imageoverlays":null}
v • d • e

v t e Emergency Notification System
Browns Ferry with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation
WEEKMONTHYEAR2025-08-02T04:50:00 [Table view]
[ENS list for Browns Ferry]

@@ Line 16: / Line 16: @@
 | event date = 09/17/2005 11:29 CDT
 | last update date = 09/17/2005
-| title = Reactor Scram Due To Maintenance
+| title = Reactor Scram Due to Maintenance
 | event text = On 09/17/2005 at 1129 CDT, Browns Ferry Unit 3 reactor automatically scrammed due to the trip of the main generator turbine on low main condenser vacuum.  Prior to the trip, the unit was operating at reduced power (74 percent) and maintenance was in progress to repair in place a secondary plant moisture separator level control valve. This maintenance activity resulted in the low condenser vacuum condition.
 Plant response to the scram was as expected.  Post-scram transient RPV low water level caused a valid automatic initiation of primary containment isolation (PCIS) valves group 2 (containment sumps and shutdown cooling valves), group 3 (reactor water cleanup system), group 6 (ventilation systems, including initiation of standby gas treatment and control room emergency ventilation systems), and group 8 (traversing in-core probe system).

Latest revision as of 21:20, 1 March 2018