Electrohydraulic Control (EHC) is the fluid control device for a system, to control how valves should open or close using liquid pressure. A primary system which uses EHC is the Main Turbine.
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| | Site | Start date | Title | Description |
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| IR 05000333/2025003 | FitzPatrick | 22 December 2025 | Integrated Inspection Report 05000333/2025003 and Independent Spent Fuel Storage Installation Report 07200012/2025001 and Exercise of Enforcement Discretion | | | IR 05000387/2025003 | Susquehanna | 22 December 2025 | Integrated Inspection Report 05000387/2025003 and 05000388/2025003, Independent Spent Fuel Storage Installation IR 07200028/2024001 and 07200028/2025001, and Exercise of Enforcement Discretion | | | 05000321/LER-2025-002, Reactor Protection System Instrumentation for Turbine Control Valve Fast Closure Inoperable | Hatch | 19 December 2025 | Reactor Protection System Instrumentation for Turbine Control Valve Fast Closure Inoperable | | | IR 05000483/2025003 | Callaway | 18 December 2025 | Integrated Inspection Report 05000483/2025003 | | | IR 05000261/2025003 | Robinson | 1 December 2025 | Integrated Inspection Report 05000261/2025003 | | | 05000446/LER-2025-003, Failure of Turbine Electrohydraulic Control System Results in Manual Trip of Unit 2 and Actuation of the Auxiliary Feedwater System | Comanche Peak | 13 November 2025 | Failure of Turbine Electrohydraulic Control System Results in Manual Trip of Unit 2 and Actuation of the Auxiliary Feedwater System | | | IR 05000395/2025002 | Summer | 6 August 2025 | Integrated Inspection Report 05000395/2025002 | | | ML25160A299 | South Texas | 24 June 2025 | Annual Assessment Meeting - NRC Presentation Slides | | | ENS 57705 | Browns Ferry | 12 May 2025 18:53:00 | Automatic Reactor Trip | The following information was provided by the licensee via phone and email:
At 1353 CDT on May 12, 2025, with Unit 2 in Mode 1 at 100 percent power, the reactor automatically tripped due to a turbine trip caused by a loss of the electrohydraulic control (EHC) system. The trip was not complex, with all systems responding normally post-trip with the exception of the turbine bypass valves due to the loss of EHC.
Operations responded and stabilized the plant. At 1407 with Unit 2 in Mode 3, there was a second automatic reactor trip due to a low reactor water level transient caused by manually opening and closing a main steam relief valve. Reactor water level is being maintained via feed water pump. Decay heat is being removed by discharging steam (via main steam line drains) to the main condenser. Units 1 and 3 are not affected.
Due to the reactor protection system (RPS) actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B).
Additionally, due to the actuation of RPS and groups 2, 3, 6, and 8 of the primary containment isolation system, this event is being reported as an eight-hour, non-emergency notification per 50.72(b)(3)(iv)(A).
There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector was notified. | | ML25051A210 | Watts Bar
Sequoyah | 31 March 2025 | Issuance and Amendment Nos. 371, 365, 173 and 78 Regarding Revision to Technical Specification Table 3.3.2-1, Function 5 | |
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