ENS 57850: Difference between revisions

v t e ENS Event
23:10 Jun 10, 2025
Title	60-DAY Optional Telephonic Notification for Invalid Containment Isolation
Event Description	The following information was provided by the licensee via phone and email: This 60-day telephone notification is being made per the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation of a general containment isolation signal affecting more than one system. On June 10, 2025, Unit 2 operations personnel received an `A' channel half scram and entered 2-AOI-99-1. Motor generator set 2A was shut down and reactor protection system `A' was swapped to alternate. This resulted in primary containment isolation system (PCIS) groups 2, 3, 6, and 8 isolations, and initiation of standby gas treatment (SGT) trains `A', `B', and `C' and control room emergency ventilation system (CREV) train `A'. All affected safety systems responded as expected. Plant conditions which initiate PCIS groups 2 and 8 actuations are reactor vessel low water level and high drywell pressure. Plant conditions which initiate PCIS group 3 actuations, are reactor vessel low water level and reactor water cleanup area high temperature. Plant conditions which initiate PCIS group 6, CREV and SGT actuations, are reactor vessel low water level, high drywell pressure, or reactor building ventilation exhaust high radiation (reactor zone or refuel zone). At the time of the event, these conditions did not exist; the actuation was due to a loss of power and not due to a low reactor water level or drywell pressure. Therefore, the actuation of the PCIS, CREV, and SGT was invalid. Upon investigation, the 2A2 circuit protector was found to have charred wire on the top right lug. The terminal block was replaced. There were no safety consequences or impact to the health and safety of the public as a result of this event. This event was entered into the corrective action program as condition report 2019406.

ENS 57850 +/-
Where
Browns Ferry Alabama (NRC Region 2)
Reporting

10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation
Time - Person (Reporting Time:+1336.3 h55.679 days <br />7.954 weeks <br />1.83 months <br />)
Opened:	Alexander Neumann 15:28 Aug 5, 2025
NRC Officer:	Jon Lilliendahl
Last Updated:	Aug 5, 2025
57850 - 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 57850\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\u003E60-DAY Optional Telephonic Notification for Invalid Containment Isolation\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 57850 - 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 50.73(a)(1), Submit an LER
WEEKMONTHYEAR	60-Day Optional Telephonic Notification of an Invalid Actuation of a General Containment Isolation Signal Affecting More than One System	60-Day Optional Telephonic Notification of an Invalid Specified System Actuation 2025-06-10T23:10:00 [Table view]
[ENS list for Browns Ferry]

@@ Line 25: / Line 25: @@
 There were no safety consequences or impact to the health and safety of the public as a result of this event.
 This event was entered into the corrective action program as condition report 2019406.
-| URL = https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2025/20250806en.html#en57850
+| URL = https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2025/20250807en.html#en57850
 }}{{unit info
 | Unit = 1

v t e Unit 1
GE-4
Reactor critical	Critical
Scram	No
Before	(100 %)
After	(83 %)

v t e Unit 2
GE-4
Reactor critical	Critical
Scram	No
Before	(100 %)
After	(100 %)

v t e Unit 3
GE-4
Reactor critical	Critical
Scram	No
Before	(100 %)
After	(0 %)

ENS 57850: Difference between revisions

Latest revision as of 06:20, 7 August 2025

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ENS 57850: Difference between revisions

Latest revision as of 06:20, 7 August 2025

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