WEEKMONTHYEAR05000458/LER-2025-005, For River Bend Station, Unit 1, Containment Unit Coolers Inoperable Due to Compensatory Measures2025-10-200Start date: 20 October 2025 Site: River Bend Reporting criterion: 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000458/LER-2025-006, For River Bend Station, Potential Loss of Safety Function of Control Building Chillers Due to a Valve Mispositioned2025-10-200Start date: 20 October 2025 Site: River Bend Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation, 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition, 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2)(i), 10 CFR 50.73(a)(2)(x), 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded, 10 CFR 50.73(a)(2)(iii), 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown, 10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System, 10 CFR 50.73(a)(2)(viii)(A), 10 CFR 50.73(a)(2)(viii)(B) 05000282/LER-2025-002, Control Room Chiller Inoperable Due to Purge System Failure2025-10-100Start date: 10 October 2025 Site: Prairie Island Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000317/LER-2025-001, Control Room Loss of Ventilation Due to Smoke Detector Failure Causing Common Supply Damper to Shut2025-09-290Start date: 29 September 2025 Site: Calvert Cliffs Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 05000341/LER-2025-001-01, Cancellation of Licensee Event Report LER 2025-001-01, Div. 1 Transformer 64 Load Tap Changer Failure Potentially Prohibited by Technical Specifications and Potential Loss of Safety Function2025-09-260Start date: 26 September 2025 Site: Fermi Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000263/LER-2025-004, Rainwater Intrusion Caused by Reactor Building Ventilation and Rise in Steam Chase Temperature2025-09-250Start date: 25 September 2025 Site: Monticello Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation, 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000458/LER-2025-004, Unsecured Pressure Boundary Door Resulting in Condition That Could Have Prevented Fulfillment of a Safety Function2025-09-160Start date: 16 September 2025 Site: River Bend Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000413/LER-2025-003, B Emergency Diesel Generator Field Failed to Flash2025-09-150Start date: 15 September 2025 Site: Catawba Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000341/LER-2025-001, Division 1 Transformer 64 Load Tap Changer Failure Potenially Prohibited by Technical Specifications and Potential Loss of Safety Function2025-08-140Start date: 14 August 2025 Site: Fermi Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000458/LER-2025-003, Turbine Control Valve Closure Results in Loss of Safety Function2025-08-140Start date: 14 August 2025 Site: River Bend Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation, 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition, 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2)(i), 10 CFR 50.73(a)(2)(x), 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded, 10 CFR 50.73(a)(2)(iii), 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown, 10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System, 10 CFR 50.73(a)(2)(viii)(A), 10 CFR 50.73(a)(2)(viii)(B) 05000483/LER-2025-002, Reactor Vessel Bottom Head (Rvbh) Bottom Mounted Instrument (Bmi) Nozzle Pressure Boundary Leakage2025-07-020Start date: 2 July 2025 Site: Callaway Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 05000483/LER-2025-001, Refueling Water Storage Tank Lowered Below TS 3.5.4 Limit2025-07-010Start date: 1 July 2025 Site: Callaway Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000254/LER-2025-004, Loss of Suppression Chamber Vacuum Breaker Safety Function Due to Configuration Control Error2025-06-040Start date: 4 June 2025 Site: Quad Cities Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000263/LER-2024-002-01, Low Pressure Coolant Injection Inoperable Due to Motor Valve Failure2025-05-300Start date: 30 May 2025 Site: Monticello Reporting criterion: 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000382/LER-2025-002, Auxiliary Pressurizer Spray Train Inoperable Resulting in a Condition Prohibited by Technical Specifications2025-05-290Start date: 29 May 2025 Site: Waterford Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation, 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition, 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2)(i), 10 CFR 50.73(a)(2)(x), 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded, 10 CFR 50.73(a)(2)(iii), 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown, 10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System, 10 CFR 50.73(a)(2)(viii)(A), 10 CFR 50.73(a)(2)(viii)(B) 05000366/LER-2025-002, A Emergency Diesel Generator Inoperable Due to Inadvertent Overspeed Trip2025-05-230Start date: 23 May 2025 Site: Hatch Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000499/LER-2024-002-01, Two Control Room Envelope HVAC Trains Inoperable Resulting in a Condition That Could Have Prevented Fulfillment of a Safety Function2025-05-120Start date: 12 May 2025 Site: South Texas Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000353/LER-2025-001, HPCI Valve Isolated During a Surveillance Test Due to a Degraded Test Connector2025-05-020Start date: 2 May 2025 Site: Limerick Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000366/LER-2025-001, Primary Containment Inoperable Due to Exceeding Technical Specification Allowable Leakage Limits2025-04-170Start date: 17 April 2025 Site: Hatch Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 05000498/LER-2025-001, Two Inoperable Emergency Core Cooling System Trains Resulting in Potential Loss of Safety Function2025-04-070Start date: 7 April 2025 Site: South Texas Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000254/LER-2025-002, Control Room Emergency Ventilation Air Conditioning System Inoperable Due to Logic Issue2025-03-270Start date: 27 March 2025 Site: Quad Cities Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000316/LER-2024-004-01, AB Emergency Diesel Generator Inoperable for Longer than Allowed by Technical Specifications2025-03-270Start date: 27 March 2025 Site: Cook Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000390/LER-2025-001, Loss of the Control Room Emerency Air Temperature Control System Due to Chiller Oil Migration2025-03-030Start date: 3 March 2025 Site: Watts Bar Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000440/LER-2024-004, Division 3 Diesel Generator Inoperable Due to Low Output Voltage Resulting in Loss of Safety Function2025-02-240Start date: 24 February 2025 Site: Perry Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000298/LER-2024-003-01, High Pressure Coolant Injection Steam Leak Causes Condition That Could Have Prevented Fulfillment of a Safety Function and a Condition Prohibited by Technical Specifications2025-02-200Start date: 20 February 2025 Site: Cooper Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000446/LER-2024-002-01, Turbine Driven Auxiliary Feedwater Pump Unavailable Following Transition from Mode 4 to Mode 32025-02-130Start date: 13 February 2025 Site: Comanche Peak Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000313/LER-2024-002, ANO Unit 1 Inoperable Containment Isolation Boundary2025-02-060Start date: 6 February 2025 Site: Arkansas Nuclear Reporting criterion: 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000440/LER-2024-005, Division 3 Diesel Generator Inoperable Due to Failure of the Right Bank Air Start Motor2025-01-230Start date: 23 January 2025 Site: Perry Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000391/LER-2025-001, Loss of the Control Room Emergency Air Temperature Control System Due to Chiller Valve Malfunction2025-01-210Start date: 21 January 2025 Site: Watts Bar Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000446/LER-2024-002, Turbine Driven Auxiliary Feedwater Pump Unavailable Following Transition from Mode 4 to Mode 32025-01-160Start date: 16 January 2025 Site: Comanche Peak Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000270/LER-2024-001, Common Cause Inoperability of Both Trains of Control Room Ventilation System Outside Air Booster Fans Due to Supply Breaker Wiring Deficiency Resulted in a Condition That Have Prevented Fulfillment2024-12-190Start date: 19 December 2024 Site: Oconee Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 05000346/LER-2021-001-02, Emergency Diesel Generator Speed Switch Failure Due to Direct Current System Ground2024-12-090Start date: 9 December 2024 Site: Davis Besse Reporting criterion: 10 CFR 50.73(a)(1), Submit an LER, 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000423/LER-2024-002, Door Latch Failure Resulted in Loss of Safety Function for Secondary Containment Boundary2024-11-260Start date: 26 November 2024 Site: Millstone Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000260/LER-2024-002-01, High Pressure Coolant Injection Inoperable Due to Rupture Disc Failure and Resulting System Isolation2024-11-250Start date: 25 November 2024 Site: Browns Ferry Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000416/LER-2024-004, High Pressure Core Spray Over Frequency Relay Trip2024-11-220Start date: 22 November 2024 Site: Grand Gulf Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000316/LER-2024-004, AB Emergency Diesel Generator Inoperable for Longer than Allowed by Technical Specifications2024-11-110Start date: 11 November 2024 Site: Cook Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000499/LER-2024-003, Containment Isolation Valve Inoperable Resulting in Condition Prohibited by Technical Specification and Prevention of Fulfillment of Safety Function2024-10-220Start date: 22 October 2024 Site: South Texas Reporting criterion: 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000499/LER-2024-002, Two Control Room Envelope HVAC Trains Inoperable Resulting in a Condition That Could Have Prevented Fulfillment of a Safety Function2024-10-170Start date: 17 October 2024 Site: South Texas Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000395/LER-2024-002, Loss of Control Room Emergency Filtration System2024-10-150Start date: 15 October 2024 Site: Summer Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000423/LER-2024-001, Loss of Safety Function and Condition Prohibited by Technical Specifications for Loss of Secondary Containment Boundary2024-10-140Start date: 14 October 2024 Site: Millstone Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000483/LER-2024-002, Concurrent Inoperability of Control Room Air Conditioning System Train and Opposite Train Emergency Diesel Generator Results in Condition Prohibited by Technical Specifications Limiting2024-10-010Start date: 1 October 2024 Site: Callaway Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000346/LER-2021-001-01, Emergency Diesel Generator Speed Switch Failure Due to Direct Current System Ground2024-09-190Start date: 19 September 2024 Site: Davis Besse Reporting criterion: 10 CFR 50.73(a)(1), Submit an LER, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000387/LER-2024-002, B Diesel Generator Inoperable Due to Failed Excitation System Linear Reactor2024-09-160Start date: 16 September 2024 Site: Susquehanna Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000354/LER-2024-001-01, Invalid Primary Containment Integrated Leak Rate As-Found Test (ILRT) Supplement2024-09-050Start date: 5 September 2024 Site: Hope Creek Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 05000263/LER-2024-002, Low Pressure Coolant Injection Inoperable Due to Motor Valve Failure2024-08-270Start date: 27 August 2024 Site: Monticello Reporting criterion: 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05200026/LER-2024-001, Manual Reactor Protection System Actuation Due to Procedure Not Optimally Sequenced to Reset the Rapid Power Reduction Signal2024-08-060Start date: 6 August 2024 Site: Vogtle Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation, 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(x), 10 CFR 50.73(a)(2) 05000391/LER-2024-003, Inoperability of Both Trains of Unit 2 Low Head Safety Injection2024-07-110Start date: 11 July 2024 Site: Watts Bar Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000334/LER-2024-003, Unanalyzed Containment Bypass Condition Due to Degraded River Water Piping2024-07-020Start date: 2 July 2024 Site: Beaver Valley Reporting criterion: 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 05000499/LER-2024-001, Automatic Reactor Trip and Actuation of Two of Three Emergency Diesel Generators2024-07-020Start date: 2 July 2024 Site: South Texas Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation, 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000498/LER-2024-003, Condition Prohibited by Technical Specifications and Potential Loss of Safety Function Due to Inoperable Low Head Safety Injection Pump2024-07-010Start date: 1 July 2024 Site: South Texas Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000440/LER-2024-002, Reactor Water Clean Up Leak Detection Loss of Safety Function2024-06-270Start date: 27 June 2024 Site: Perry Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000498/LER-2024-002-01, Two Essential Chilled Water Trains Inoperable Resulting in a Condition That Could Have Prevented Fulfillment of a Safety Function2024-06-270Start date: 27 June 2024 Site: South Texas Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000530/LER-2024-002, Invalid Specified System Actuation of Train B Emergency Diesel Generator2024-06-250Start date: 25 June 2024 Site: Palo Verde Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000498/LER-2023-003-01, Two Essential Chilled Water Trains Inoperable Resulting in a Condition That Could Have Prevented Fulfillment of a Safety Function2024-06-190Start date: 19 June 2024 Site: South Texas Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000298/LER-2023-002-01, Secondary Containment Differential Pressure Perturbation Exceeds Technical Specifications2024-06-060Start date: 6 June 2024 Site: Cooper Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000529/LER-2024-001, Valid Specified System Actuations of Unit 2 Train B Emergency Diesel Generator and Train B Auxiliary Feedwater2024-05-230Start date: 23 May 2024 Site: Palo Verde Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation, 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000260/LER-2024-002, High Pressure Coolant Injection Inoperable Due to Rupture Disc Failure and Resulting System Isolation2024-05-200Start date: 20 May 2024 Site: Browns Ferry Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000341/LER-2024-001, Automatic RPS Scram on High RPV Pressure While Attempting to Lower Generator Output During RF-222024-05-150Start date: 15 May 2024 Site: Fermi Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation, 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition, 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2)(i), 10 CFR 50.73(a)(2)(x), 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded, 10 CFR 50.73(a)(2)(iii), 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown, 10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System, 10 CFR 50.73(a)(2)(viii)(A), 10 CFR 50.73(a)(2)(viii)(B) 05000445/LER-2024-001, Re Potential Loss of Safety Function Due to Inoperability of Both Trains of Uninterruptible Power Supply Heating, Ventilation & Air Conditioning2024-05-060Start date: 6 May 2024 Site: Comanche Peak Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000498/LER-2023-004-01, Condition Prohibited by Technical Specifications Due to Inoperable Train of Essential Chilled Water2024-04-250Start date: 25 April 2024 Site: South Texas Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000298/LER-2024-003, High Pressure Coolant Injection Steam Leak Causes Condition That Could Have Prevented Fulfillment of a Safety Function and a Condition Prohibited by Technical Specifications2024-04-220Start date: 22 April 2024 Site: Cooper Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000325/LER-2024-001, Primary Containment Penetration Local Leak Rate Testing Failure2024-04-100Start date: 10 April 2024 Site: Brunswick Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 05000321/LER-2024-001, Primary Containment Penetration Exceeded Maximum Allowable Primary Containment Leakage Rate (La)2024-04-090Start date: 9 April 2024 Site: Hatch Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 05000498/LER-2024-001, Re Two Steam Generator Power Operated Relief Valves (Porvs) Inoperable Resulting in a Condition That Could Have Prevented Fulfillment of a Safety Function2024-04-010Start date: 1 April 2024 Site: South Texas Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000416/LER-2024-001, High Pressure Core Spray Inoperable Due to Minimum Flow Valve Failure to Close2024-03-270Start date: 27 March 2024 Site: Grand Gulf Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000414/LER-2024-001, Condition Prohibited by Technical Specifications and Loss of Safety Function Due to Failed Damper Controller for the 2A1 Emergency Diesel Generator Room Ventilation Fan2024-03-040Start date: 4 March 2024 Site: Catawba Reporting criterion: 10 CFR 50.73(a)(1), Submit an LER, 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(8) 05000366/LER-2024-001, High Pressure Coolant Injection (HPCI) System Inoperable2024-02-140Start date: 14 February 2024 Site: Hatch Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000528/LER-2023-003, Control Room Essential Filtration Actuation Signal (CREFAS) Actuation with Essential Spray Pond Pump Start2024-02-010Start date: 1 February 2024 Site: Palo Verde Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(iv)(B)(9) 05000259/LER-2023-003, Standby Liquid Control Inoperable Due to Demineralized Water In-Leakage2024-01-290Start date: 29 January 2024 Site: Browns Ferry Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000237/LER-2023-001, HPCI Inoperable Due to Air Void Accumulation2024-01-190Start date: 19 January 2024 Site: Dresden Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000499/LER-2023-001, Two Essential Chilled Water Trains Inoperable Resulting in a Condition That Could Have Prevented Fulfillment of a Safety Function2024-01-150Start date: 15 January 2024 Site: South Texas Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000498/LER-2023-003, Two Essential Chilled Water Trains Inoperable Resulting in a Condition That Could Have Prevented Fulfillment of a Safety Function2024-01-090Start date: 9 January 2024 Site: South Texas Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000298/LER-2023-002, Secondary Containment Differential Pressure Perturbation Exceeds Technical Specifications2023-12-200Start date: 20 December 2023 Site: Cooper Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000339/LER-2023-001, Reactor Coolant Pressure Boundary Leak Due to Poor Weld Workmanship2023-11-300Start date: 30 November 2023 Site: North Anna Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(1) 05000458/LER-2022-004-01, High Pressure Core Spray Inoperable Due to Transformer Failure2023-11-150Start date: 15 November 2023 Site: River Bend Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000259/LER-2022-002-01, High Pressure Coolant Injection System Declared Inoperable Due to a Corroded Actuator2023-10-120Start date: 12 October 2023 Site: Browns Ferry Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000445/LER-2023-001-01, (Cpnpp), Automatic Reactor Trip Due to Lo-Lo Steam Generator Level2023-10-120Start date: 12 October 2023 Site: Comanche Peak Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000315/LER-2023-001, Two Trains of Fuel Handling Area Exhaust Ventilation Inoperable2023-09-280Start date: 28 September 2023 Site: Cook Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000333/LER-2022-003-02, Safety Relief Valves Lift Setpoint Found Out of Tolerance Low2023-09-080Start date: 8 September 2023 Site: FitzPatrick Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000445/LER-2023-001, Automatic Reactor Trip Due to Lo-Lo Steam Generator Level2023-08-150Start date: 15 August 2023 Site: Comanche Peak Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000498/LER-2023-001-01, Supplement to Pressurizer Power Operated Valve Failed to Open2023-07-260Start date: 26 July 2023 Site: South Texas Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000354/LER-2023-001, Technical Specification Required Shutdown Due to Declaring the Suppression Chamber and Primary Containment Inoperable2023-06-200Start date: 20 June 2023 Site: Hope Creek Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 05000373/LER-2023-001, Low Pressure Core Spray Inoperable Due to Minimum Flow Valve Flow Pressure Switch Failure2023-06-160Start date: 16 June 2023 Site: LaSalle Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000250/LER-2023-001, RCS Pressure Boundary Degraded2023-06-140Start date: 14 June 2023 Site: Turkey Point Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation, 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2)(i), 10 CFR 50.73(a)(2)(x), 10 CFR 50.73(a)(2)(iii), 10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System, 10 CFR 50.73(a)(2)(viii)(B) 05000259/LER-2023-001-01, High Pressure Coolant Injection System Inoperable Due to a Torn Valve Diaphragm2023-06-130Start date: 13 June 2023 Site: Browns Ferry Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000498/LER-2023-001, Pressurizer Power Operated Relief Valve Failed to Open2023-06-120Start date: 12 June 2023 Site: South Texas Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000443/LER-2023-001, Automatic Actuation of B Emergency Diesel Generator Emergency Power Sequencer2023-06-120Start date: 12 June 2023 Site: Seabrook Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation, 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition, 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2)(i), 10 CFR 50.73(a)(2)(x), 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded, 10 CFR 50.73(a)(2)(iii), 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown, 10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System, 10 CFR 50.73(a)(2)(viii)(A), 10 CFR 50.73(a)(2)(viii)(B) 05000244/LER-2023-001, Vital Bus 17 Failed to Load Onto Emergency Diesel Generator B During Load / Safeguard Sequence Testing; Corroded Breaker Shunt Trip Attachment Plunger Found Which Indicated an Earlier Violation of Technical Specification 3.8.12023-06-070Start date: 7 June 2023 Site: Ginna Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000387/LER-2023-002, Unplanned Lnoperability of the High Pressure Coolant Injection (HPCI) System Due Failure of the HPCI Turbine Stop Valve to Fully Close, Most Likely Due to Internal Corrosion and2023-06-060Start date: 6 June 2023 Site: Susquehanna Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000388/LER-2023-001, Secondary Containment Bypass Leakage Limit Exceeded Due Inadequate Procedure Guidance Resulting in Failure of the Inboard Containment Isolation Valve to Close and Pressurize2023-05-250Start date: 25 May 2023 Site: Susquehanna Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 05000374/LER-2021-002-02, Supplement to Reactor Protection System Half Scram Due to Motor Generator Set Output Breaker Trip2023-05-250Start date: 25 May 2023 Site: LaSalle Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation, 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition, 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2)(x), 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded, 10 CFR 50.73(a)(2)(iii), 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown, 10 CFR 50.73(a)(2), 10 CFR 50.73(a)(2)(viii)(A), 10 CFR 50.73(a)(2)(viii)(B) 05000458/LER-2023-001, Ultimate Heat Sink Inoperable Due to Boundary Valve Leakage2023-05-230Start date: 23 May 2023 Site: River Bend Reporting criterion: 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2) 05000298/LER-2023-001, Valve Test Failures Result in Condition Prohibited by Technical Specifications2023-05-080Start date: 8 May 2023 Site: Cooper Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000333/LER-2022-003-01, Safety Relief Valves Lift Setpoint Found Out of Tolerance Low2023-04-280Start date: 28 April 2023 Site: FitzPatrick Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000440/LER-2023-002, Main Steam Line Leakage Exceeded Technical Specification Limit2023-04-260Start date: 26 April 2023 Site: Perry Reporting criterion: 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000366/LER-2023-001, Primary Containment Penetration Exceeded Maximum Allowable Primary Containment Leakage Rate (La)2023-04-050Start date: 5 April 2023 Site: Hatch Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 05000259/LER-2023-001, High Pressure Coolant Injection System Inoperable Due to a Torn Valve Diaphragm2023-03-270Start date: 27 March 2023 Site: Browns Ferry Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function 05000374/LER-2022-003-01, Manual Scram Due to Lsophase Bus Duct Fire Followed by 2A RPS Normal Power Supply Trip2023-02-090Start date: 9 February 2023 Site: LaSalle Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation, 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability, 10 CFR 50.73(a)(2)(x), 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded, 10 CFR 50.73(a)(2)(iii), 10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System, 10 CFR 50.73(a)(2), 10 CFR 50.73(a)(2)(viii)(A), 10 CFR 50.73(a)(2)(viii)(B), 10 CFR 50.73(a)(2)(1) 05200025/LER-2022-002-01, Automatic Depressurization System Stage 4 Flow Paths Inoperable During Mode 6 with Upper Internals in Place Due to Inadequate Work Processes2023-02-030Start date: 3 February 2023 Site: Vogtle Reporting criterion: 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 05000382/LER-2022-001-01, On Non-Compliance with Technical Specifications Due to Incorrect Procedural Guidance for Radiation Monitors2023-01-030Start date: 3 January 2023 Site: Waterford Reporting criterion: 10 CFR 50.73(a)(2)(iv)(A), System Actuation, 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition, 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.73(a)(2)(v), Loss of Safety Function, 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability, 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications, 10 CFR 50.73(a)(2)(i), 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded, 10 CFR 50.73(a)(2)(iii), 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown, 10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System, 10 CFR 50.73(a)(2)(viii)(A), 10 CFR 50.73(a)(2)(viii)(B)
[Table view] |