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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 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 | | | ML25087A218 | Palisades | 28 March 2025 | NRC Staff Answer to Petitioning Organizations Amended and New Contentions | | | ML25045A168 | | 14 February 2025 | Tsuruga 2025 Cyber Inspection Plan - Training Use Only | | | ENS 57540 | Summer | 10 February 2025 17:16:00 | Manual Reactor Trip Due to Electrohydraulic Control System Leak | ?
The following information was provided by the licensee via phone and email:
At 1216 EST, on 2/10/2025 with Unit 1 in mode 1 at 66.5 percent power, the reactor was manually tripped due to an electro-hydraulic control power system leak. The trip was not complex with all systems responding normally post-trip.
Operations responded and stabilized the plant. Decay heat is being removed by the emergency feedwater system.
Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR50.72(b)(2)(iv)(B) and an eight-hour, non-emergency notification per 10CFR 50.72(b)(3)(iv)(A) resulting from a valid actuation of the reactor protection and emergency feedwater systems.
There was no impact on the health and safety of the public or plant personnel.
The NRC Resident Inspector has been notified. | | CNL-25-013, CNL-25-013 SQN U2 Request for Exemption from Part 26 Work Hours | Sequoyah | 5 February 2025 | CNL-25-013 SQN U2 Request for Exemption from Part 26 Work Hours | | | PNP 2024-049, Response to Request for Additional Information Regarding the License Amendment Request to Reinstate the Operating Technical Specifications | Palisades | 19 December 2024 | Response to Request for Additional Information Regarding the License Amendment Request to Reinstate the Operating Technical Specifications | | | ML24319A081 | Fermi
07200071 | 8 November 2024 | 5 to the Updated Final Safety Analysis Report, Chapter 14, Initial Tests and Operation | |
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