ENS 57929: Difference between revisions

Latest revision as of 22:24, 23 September 2025

v t e ENS Event
01:20 Sep 15, 2025
Title	Manual Reactor Trip
Event Description	The following information was provided by the licensee via phone and email: At 2020 CDT [on 9/14/2025], [Comanche Peak] Unit 2 reactor was manually tripped due to a malfunction of the electro-hydraulic control (EHC) system on the main turbine. All auxiliary feedwater pumps started due to steam generator `Lo-Lo' levels post trip. This event is being reported in accordance with 10 CFR 50.72(b)(2)(iv)(B) for a reactor trip and 10 CFR 50.72(b)(3)(iv)(A) for an actuation of auxiliary feedwater. Unit 2 is being maintained in hot standby (mode 3) in accordance with integrated plant operating procedures. Decay heat is being rejected to the main condenser via the steam dump valves." The NRC Resident Inspector was notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: Unit 1 was not affected. The cause of the malfunction of EHC is unknown and under investigation. All rods fully inserted upon the reactor being tripped.

ENS 57929 +/-
Where
Comanche Peak Texas (NRC Region 4)
Reporting

10 CFR 50.72(b)(2)(iv)(B), RPS Actuation
Time - Person (Reporting Time:+-1.07 h-0.0446 days <br />-0.00637 weeks <br />-0.00147 months <br />)
Opened:	Victor Alanis 00:16 Sep 15, 2025
NRC Officer:	Ernest West
Last Updated:	Sep 15, 2025
57929 - 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 57929\u003C/a\u003E - \u003Ca href=\"/Comanche_Peak\" title=\"Comanche Peak\"\u003EComanche Peak\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EManual Reactor Trip\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 57929 - Comanche Peak\n","link":"","lat":32.29839166666667,"lon":-97.78532222222222,"icon":"/w/images/d/d7/Luminant_icon.png"}],"imageoverlays":null}
v • d • e

v t e Emergency Notification System
Comanche Peak with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
WEEKMONTHYEAR2025-09-24T23:29:00 [Table view]
[ENS list for Comanche Peak]

@@ Line 18: / Line 18: @@
 | title = Manual Reactor Trip
 | event text = The following information was provided by the licensee via phone and email:
-At 2020 CDT [on 9/14/2025], [Comanche Peak] Unit 2 reactor was manually tripped due to a malfunction of the electro-hydraulic control (EHC) system on the main turbine. All auxiliary feedwater pumps started due to steam generator `Lo-Lo&#039; levels post trip. This event is being reported in accordance with 10 CFR 50.72(b)(2)(iv)(B) for a reactor trip and 10 CFR 50.72(b)(3)(iv)(A) for an actuation of auxiliary feedwater. Unit 2 is being maintained in hot standby (mode 3) in accordance with integrated plant operating procedures. Decay heat is being rejected to the main condenser via the steam dump valves."
+At 2020 CDT [on 9/14/2025], [Comanche Peak] Unit 2 reactor was manually tripped due to a malfunction of the electro-hydraulic control (EHC) system on the main turbine. All auxiliary feedwater pumps started due to steam generator `Lo-Lo' levels post trip. This event is being reported in accordance with 10 CFR 50.72(b)(2)(iv)(B) for a reactor trip and 10 CFR 50.72(b)(3)(iv)(A) for an actuation of auxiliary feedwater. Unit 2 is being maintained in hot standby (mode 3) in accordance with integrated plant operating procedures. Decay heat is being rejected to the main condenser via the steam dump valves."
 The NRC Resident Inspector was notified.
 The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:

v t e Unit 2
W-4-LP
Reactor critical	Critical
Scram	Yes, Manual Scram
Before	(100 %)
After	(0 %)

ENS 57929: Difference between revisions

Latest revision as of 22:24, 23 September 2025

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