Licensee Event Report

If a criteria is reached according to NUREG-1022 then a Licensee to the NRC must submit a Licensee Event Report to explain what happened.

Reporting Criteria

• 10 CFR 50.73(a)(1), Submit an LER
• 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown
• 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications (Text"Text" is a predefined property that represents text of arbitrary length and is provided by Semantic MediaWiki.: Any operation or condition which was prohibited by the plant's Technical Specifications)
• 10 CFR 50.73(a)(2)(i)(C), 50.54(x) TS Deviation
• 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded
• 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition
• 10 CFR 50.73(a)(2)(iv)(A), System Actuation
• 10 CFR 50.73(a)(2)(iv), System Actuation
• 10 CFR 50.73(a)(2)(ix)(A), Prevented Safety Function in Multiple System
• 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)(C), Loss of Safety Function - Release of Radioactive Material
• 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident
• 10 CFR 50.73(a)(2)(v), Loss of Safety Function
• 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability

Writing LERs

Explain exactly what happened during the entire event or condition, including how systems,components, and operating personnel performed. Do not cover specific hardware problems in excessive detail. Describe unique characteristics of a plant as well as other characteristics that influenced the event (favorably or unfavorably).

• Avoid using plant-unique terms and abbreviations, or, as a minimum, clearly define them.
  • The audience for LERs is large and does not necessarily know the details of each plant.
• Include the root causes, the plant status before the event, and the sequence of occurrences.
• Describe the event from the perspective of the Operator (i.e., what the operator saw, did, perceived, understood, or misunderstood).
• If several systems actuate during an event, describe all aspects of the complete event, including all actuations sequentially, and those aspects that by themselves would not be reportable.
  • For example, if a single component failure (generally not reportable) occurs following a reactor scram (reportable), describe the component failure in the narrative of the LER for the reactor scram.
• It is necessary to discuss the performance and status of equipment.
• Paraphrase pertinent sections of the latest submitted Safety analysis report (SAR) rather than referencing them because not all organizations or individuals have access to SARs.
• Extensive cross-referencing would be time consuming considering the large number of LERs and reviewers that read each LER.
• Ensure that each component's safety-significant effect on the event or condition is clearly and completely described.
• Do not use statements such as "this event is not significant with respect to the health and safety of the public" without explaining the basis for the conclusion.

Specific information that should be included, as appropriate, is described in paragraphs 50.73(b).

Submissions of LERs

Section 50.73(d) of the NUREG-1022 states that submmissions must be done with Form NRC 366 as described by section 50.4. Submissions are to be done within 60 days of the event. If that happens to be a weekend or a holiday then it must be the next working day. If a Licensee knows that a report will be late or needs an additional day or so to complete the report, the situation should be discussed with the appropriate NRC regional office. See Section 2.5 for further discussion of discovery date.

LER Forwarding Letter and Cancellations

The cover letter forwarding an LER to the NRC should be signed by a responsible official. There is no prescribed format for the letter. The date the letter is issued and the report date should be the same. Licensees are encouraged to include the NRC resident inspector and the Institute of Nuclear Power Operations (INPO) in their distribution. Multiple LERs can be forwarded by one forwarding letter. Cancellations of LERs submitted should be made by letter. The letter should state that the LER is being canceled (i.e., formally withdrawn). The bases for the cancellation should be explained so that the staff can understand and review the reasons supporting the determination. The notice of cancellation will be filed and stored with the LER and acknowledgement made in various automated data systems. The LER will be removed from the LER data base.

Voluntary LERs

Indicate information-type LERS (i.e., Voluntary LERs) by checking the "Other" block in Item 11 of the LER form and type "Voluntary Report" in the space immediately below the block. Also give a sequential LER number to the voluntary report as noted in Section 5.2.4(5). Because not all requirements of 50.73(b), "Contents," may pertain to some voluntary reports, licensees should develop the content of such reports to best present the information associated with the situation being reported. See Section 2.7 for additional discussion of Voluntary LERs.

How To Find LERs

• NRC Website search - Good for industry searching of LERs

See also

• NRC Form 366, Licensee Event Report - the NRC form
• NUREG-1022, Event Reporting Guidelines for 10 CFR 50.72 and 10 CFR 50.73

LER list

by site

1 year

Site	#	Company	Event lists
Almaraz	0	Iberdrola	[Almaraz events]	[RSS]
Arkansas Nuclear	0	Entergy	[Arkansas Nuclear events]	[RSS]
Asco	0	Endesa	[Asco events]	[RSS]
Beaver Valley	0	Vistra	[Beaver Valley events]	[RSS]
Belleville	0	Électricité de France	[Belleville events]	[RSS]
Big Rock Point	0	Consumers Energy	[Big Rock Point events]	[RSS]
Blayais	0	Électricité de France	[Blayais events]	[RSS]
Braidwood	0	Constellation	[Braidwood events]	[RSS]
Browns Ferry	0	Tennessee Valley Authority	[Browns Ferry events]	[RSS]
Brunswick	0	Duke Energy	[Brunswick events]	[RSS]
Byron	0	Constellation	[Byron events]	[RSS]
Callaway	0	Ameren	[Callaway events]	[RSS]
Calvert Cliffs	0	Constellation	[Calvert Cliffs events]	[RSS]
Catawba	0	Duke Energy	[Catawba events]	[RSS]
Chernobyl	0		[Chernobyl events]	[RSS]
Clinch River	0		[Clinch River events]	[RSS]
Clinton	0	Constellation	[Clinton events]	[RSS]
Cofrentes	0	Iberdrola	[Cofrentes events]	[RSS]
Columbia	0	Energy Northwest	[Columbia events]	[RSS]
Comanche Peak	0	Luminant	[Comanche Peak events]	[RSS]
Cook	0	American Electric Power	[Cook events]	[RSS]
Cooper	0	Entergy	[Cooper events]	[RSS]
Crane	0	Constellation	[Crane events]	[RSS]
Crystal River	0	Duke Energy	[Crystal River events]	[RSS]
Dampierre	0	Électricité de France	[Dampierre events]	[RSS]
Davis Besse	0	Cleveland Electric	[Davis Besse events]	[RSS]
Diablo Canyon	0	Pacific Gas & Electric	[Diablo Canyon events]	[RSS]
Dresden	0	Constellation	[Dresden events]	[RSS]
Duane Arnold	0	NextEra Energy	[Duane Arnold events]	[RSS]
Dungeness	0	EDF Energy	[Dungeness events]	[RSS]
Elk River	0		[Elk River events]	[RSS]
Farley	0	Southern Nuclear	[Farley events]	[RSS]
Fermi	0	DTE Energy	[Fermi events]	[RSS]
FitzPatrick	0	Constellation	[FitzPatrick events]	[RSS]
Flamanville	0	Électricité de France	[Flamanville events]	[RSS]
Fort Calhoun	0	Omaha Public Power District	[Fort Calhoun events]	[RSS]
Fort Saint Vrain	0	Xcel Energy	[Fort Saint Vrain events]	[RSS]
Fukushima Dai-Ichi	0	TEPCO	[Fukushima Dai-Ichi events]	[RSS]
Ginna	0	Constellation	[Ginna events]	[RSS]
Grand Gulf	0	Entergy	[Grand Gulf events]	[RSS]
Haddam Neck	0	Connecticut Yankee Atomic Power Co	[Haddam Neck events]	[RSS]
Hallam	0		[Hallam events]	[RSS]
Harris	0	Duke Energy	[Harris events]	[RSS]
Hartlepool	0	EDF Energy	[Hartlepool events]	[RSS]
Hatch	0	Southern Nuclear	[Hatch events]	[RSS]
Heysham	0	EDF Energy	[Heysham events]	[RSS]
Hinkley Point	0	EDF Energy	[Hinkley Point events]	[RSS]
Hope Creek	0	PSEG	[Hope Creek events]	[RSS]
Humboldt Bay	0	Pacific Gas and Electric	[Humboldt Bay events]	[RSS]
Hunterston	0	EDF Energy	[Hunterston events]	[RSS]
Indian Point	0	Entergy	[Indian Point events]	[RSS]
Jose Cabrera	0	Enresa	[Jose Cabrera events]	[RSS]
Kemmerer	0	TerraPower	[Kemmerer events]	[RSS]
Kewaunee	0	Dominion	[Kewaunee events]	[RSS]
Khmelnytskyi	0	Energoatom	[Khmelnytskyi events]	[RSS]
La Crosse	0	Dairyland Power Cooperative	[La Crosse events]	[RSS]
LaSalle	0	Constellation	[LaSalle events]	[RSS]
Lee	0	Duke Energy	[Lee events]	[RSS]
Limerick	0	Constellation	[Limerick events]	[RSS]
Maine Yankee	0	Maine Yankee	[Maine Yankee events]	[RSS]
McGuire	0	Duke Energy	[McGuire events]	[RSS]
Millstone	0	Dominion	[Millstone events]	[RSS]
Monticello	0	Xcel Energy	[Monticello events]	[RSS]
Nine Mile Point	0	Constellation	[Nine Mile Point events]	[RSS]
Nogent	0	Électricité de France	[Nogent events]	[RSS]
North Anna	0	Dominion	[North Anna events]	[RSS]
Oconee	0	Duke Energy	[Oconee events]	[RSS]
Olkiluoto	0	Teollisuuden Voima	[Olkiluoto events]	[RSS]
Oyster Creek	0	Holtec	[Oyster Creek events]	[RSS]
Palisades	0	Entergy	[Palisades events]	[RSS]
Palo Verde	0	Arizona Public Service	[Palo Verde events]	[RSS]
Parr	0		[Parr events]	[RSS]
Peach Bottom	0	Constellation	[Peach Bottom events]	[RSS]
Perry	0	FirstEnergy	[Perry events]	[RSS]
Pilgrim	0	Holtec	[Pilgrim events]	[RSS]
Point Beach	0	NextEra Energy	[Point Beach events]	[RSS]
Prairie Island	0	Xcel Energy	[Prairie Island events]	[RSS]
Quad Cities	0	Constellation	[Quad Cities events]	[RSS]
Rancho Seco	0	Sacramento Municipal Utility District	[Rancho Seco events]	[RSS]
River Bend	0	Entergy	[River Bend events]	[RSS]
Rivne	0	Energoatom	[Rivne events]	[RSS]
Robinson	0	Duke Energy	[Robinson events]	[RSS]
Saint Lucie	0	NextEra Energy	[Saint Lucie events]	[RSS]
Salem	0	PSEG	[Salem events]	[RSS]
San Onofre	0	Southern California Edison	[San Onofre events]	[RSS]
Santa Maria De Garona	0	Nuclenor	[Santa Maria De Garona events]	[RSS]
Saxton	0	GPU Nuclear	[Saxton events]	[RSS]
Seabrook	0	NextEra Energy	[Seabrook events]	[RSS]
Sequoyah	0	Tennessee Valley Authority	[Sequoyah events]	[RSS]
Shippingport	0		[Shippingport events]	[RSS]
Shoreham	0	Long Island Lighting Company	[Shoreham events]	[RSS]
Sizewell	0	EDF Energy	[Sizewell events]	[RSS]
South Texas	0	STP Nuclear Operating Company	[South Texas events]	[RSS]
South Ukraine	0	Energoatom	[South Ukraine events]	[RSS]
Summer	0	South Carolina Electric & Gas Company	[Summer events]	[RSS]
Sundesert	0	San Diego Gas & Electric Compnay	[Sundesert events]	[RSS]
Surry	0	Dominion	[Surry events]	[RSS]
Susquehanna	0	Talen Energy	[Susquehanna events]	[RSS]
Taishan	0	China Guangdong Nuclear Power Group	[Taishan events]	[RSS]
Trillo	0	Iberdrola	[Trillo events]	[RSS]
Trojan	0	Portland General Electric	[Trojan events]	[RSS]
Turkey Point	0	NextEra Energy	[Turkey Point events]	[RSS]
Vandellos	0	Endesa	[Vandellos events]	[RSS]
Vermont Yankee	0	NorthStar Vermont Yankee	[Vermont Yankee events]	[RSS]
Victoria	0	Exelon	[Victoria events]	[RSS]
Vogtle	0	Southern Nuclear	[Vogtle events]	[RSS]
Waterford	0	Entergy	[Waterford events]	[RSS]
Watts Bar	0	Tennessee Valley Authority	[Watts Bar events]	[RSS]
Wolf Creek	0	Wolf Creek Nuclear Operating Corporation	[Wolf Creek events]	[RSS]
Yankee Rowe	0		[Yankee Rowe events]	[RSS]
Zaporizhzhia	0	Enerhodar	[Zaporizhzhia events]	[RSS]
Zion	0	ZionSolutions	[Zion events]	[RSS]

	Site	Start date	Reporting criterion	System	Topic
05000263/LER-2024-002-01, Low Pressure Coolant Injection Inoperable Due to Motor Valve Failure	Monticello	30 May 2025	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	Core Spray Residual Heat Removal Emergency Core Cooling System Low Pressure Coolant Injection	Probabilistic Risk Assessment Large early release frequency
05000296/LER-2025-001-01, Automatic Reactor Scram Following Main Generator Trip	Browns Ferry	29 May 2025	10 CFR 50.73(a)(2)(iv)(A), System Actuation	Reactor Protection System Emergency Diesel Generator Primary Containment Isolation System
05000382/LER-2025-002, Auxiliary Pressurizer Spray Train Inoperable Resulting in a Condition Prohibited by Technical Specifications	Waterford	29 May 2025	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)	Reactor Coolant System	Past operability
05000339/LER-2025-001, Reactor Trip Breakers Opened Due to High Vibes on 2-RC-P-1B	North Anna	28 May 2025	10 CFR 50.73(a)(2)(iv)(A), System Actuation	Reactor Protection System Control Rod
05000364/LER-2025-002, Two Pressurizer Safety Valves Lift Pressure Outside of Technical Specifications Limits Due to Setpoint Drift	Farley	23 May 2025	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications	Reactor Coolant System Emergency Core Cooling System	Time of Discovery
05000382/LER-2025-001, Inoperability of Startup Transformer a Results in a Condition Prohibited by Technical Specifications	Waterford	23 May 2025	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications	Emergency Diesel Generator	Safe Shutdown Foreign Material Exclusion Offsite Circuit Skill of the craft
05000251/LER-2025-001-01, Degraded Condition	Turkey Point	23 May 2025	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded	Reactor Coolant System	Boric Acid
05000366/LER-2025-002, A Emergency Diesel Generator Inoperable Due to Inadvertent Overspeed Trip	Hatch	23 May 2025	10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications	Service water Emergency Diesel Generator	Overspeed trip Overspeed
05000528/LER-2025-001, Unit 1 Loss of High Pressure Safety Injection Safety Function	Palo Verde	22 May 2025
05000440/LER-2025-001, Automatic Actuation of Division 3 Diesel Generator Resulting from Startup Transformer Testing	Perry	21 May 2025	10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(iv)(B)(8)	Service water Emergency Diesel Generator High Pressure Core Spray Residual Heat Removal Emergency Core Cooling System Decay Heat Removal	Fuel cladding
05000263/LER-2025-001, Automatic Reactor Scram on Low Water Level	Monticello	16 May 2025
05000315/LER-2025-001, Two Main Steam Safety Valves Failed Setpoint Testing	Cook	15 May 2025		Main Steam Safety Valve
05000416/LER-2025-002, Automatic Emergency Diesel Generator Actuation Caused by Grid Transient	Grand Gulf	13 May 2025		Emergency Diesel Generator
05000499/LER-2024-002-01, Two Control Room Envelope HVAC Trains Inoperable Resulting in a Condition That Could Have Prevented Fulfillment of a Safety Function	South Texas	12 May 2025	10 CFR 50.73(a)(2)(v), Loss of Safety Function	HVAC Control Room Envelope
05000254/LER-2025-003, Main Steam Isolation Valves Local Leak Rate Test Exceed Technical Specification Limits	Quad Cities	9 May 2025	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications	Main Steam Isolation Valve Primary containment Main Steam Line Main Steam
05000251/LER-2025-002, Emergency Diesel Generator Actuation	Turkey Point	9 May 2025	10 CFR 50.73(a)(2)(iv)(A), System Actuation	Emergency Diesel Generator	Safe Shutdown Loss of Offsite Power
05000353/LER-2025-001, HPCI Valve Isolated During a Surveillance Test Due to a Degraded Test Connector	Limerick	2 May 2025	10 CFR 50.73(a)(2)(v), Loss of Safety Function	High Pressure Coolant Injection Primary containment Core Spray Residual Heat Removal Automatic Depressurization System Emergency Core Cooling System	Test box
05000324/LER-2025-001, Automatic Actuation of Containment Isolation Valves During Testing	Brunswick	1 May 2025	10 CFR 50.73(a)(2)(iv)(A), System Actuation	Main Steam Isolation Valve Primary Containment Isolation System Primary containment Main Condenser
05000296/LER-2024-004-01, Reactor Coolant System Pressure Boundary Leakage Identified from Recirculation System Small Bore Piping	Browns Ferry	24 April 2025	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications	Reactor Coolant System	Pressure Boundary Leakage Unidentified leakage
05000352/LER-2025-001, Bypass Leakage on the B Train of Standby Gas Treatment System HEPA Filters Exceeded Technical Specification Value	Limerick	21 April 2025	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications	Standby Gas Treatment System
05000269/LER-2025-001, Inoperability of Keowee Hydroelectric Unit Due to Legacy Deficiencies in Generator Exceiter Speed Switch Calibration Procedure Resulting in a Condition Prohibited by Technical Specifications	Oconee	21 April 2025	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications	Reactor Coolant System Service water	Probabilistic Risk Assessment
05000366/LER-2025-001, Primary Containment Inoperable Due to Exceeding Technical Specification Allowable Leakage Limits	Hatch	17 April 2025	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	Primary containment	Local Leak Rate Testing Large early release frequency
05000416/LER-2025-001, Manual Scram Due to Degraded Condenser Vacuum	Grand Gulf	16 April 2025	10 CFR 50.73(a)(2)(iv)(A), System Actuation	Reactor Protection System Emergency Diesel Generator Control Rod
05000327/LER-2024-001-01, Reactor Trip Due to a Turbine Trip	Sequoyah	9 April 2025	10 CFR 50.73(a)(2)(iv), System Actuation	Reactor Protection System Auxiliary Feedwater
05000327/LER-2024-002-01, Treactor Trip Due to a Turbine Trip	Sequoyah	9 April 2025	10 CFR 50.73(a)(2)(iv), System Actuation	Reactor Protection System Auxiliary Feedwater
05000296/LER-2025-001, Automatic Reactor Scram Following Main Generator Trip	Browns Ferry	9 April 2025	10 CFR 50.73(a)(2)(iv)(A), System Actuation	Reactor Protection System Emergency Diesel Generator Primary Containment Isolation System
05000335/LER-2025-001-01, Safety Injection Tank Above Technical Specifications Limit	Saint Lucie	8 April 2025	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
05000498/LER-2025-001, Two Inoperable Emergency Core Cooling System Trains Resulting in Potential Loss of Safety Function	South Texas	7 April 2025	10 CFR 50.73(a)(2)(v), Loss of Safety Function	HVAC Emergency Core Cooling System Control Room Envelope
05000395/LER-2025-001, (Vcsns), Manual Reactor Trip Due to Unisolable EHC Leak	Summer	7 April 2025	10 CFR 50.73(a)(2)(iv)(A), System Actuation	Feedwater Main Turbine Emergency Feedwater System	Through-Wall Leak
05000412/LER-2025-001, Automatic Reactor Trip and Automatic Actuation of the Auxiliary Feedwater System Due to Loose Feedback Linkage on Feedwater Regulating Valve	Beaver Valley	1 April 2025	10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(iv)(B)(6) 10 CFR 50.73(a)(2)(iv)(B)(1)	Steam Generator Feedwater Reactor Protection System Auxiliary Feedwater Main Steam	Large early release frequency
05000413/LER-2025-001, Plant Shutdown Required by Technical Specifications Due to Unidentified Reactor Coolant System Leakage	Catawba	31 March 2025	10 CFR 50.73(a)(1), Submit an LER 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown	Reactor Coolant System	Aging Management License Renewal Pressure Boundary Leakage Unidentified leakage Operational leakage
05000254/LER-2025-002, Control Room Emergency Ventilation Air Conditioning System Inoperable Due to Logic Issue	Quad Cities	27 March 2025	10 CFR 50.73(a)(2)(v), Loss of Safety Function	HVAC Control Room Emergency Ventilation Control Room Envelope
05000316/LER-2024-004-01, AB Emergency Diesel Generator Inoperable for Longer than Allowed by Technical Specifications	Cook	27 March 2025	10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications	Service water Emergency Diesel Generator	Mission time Probabilistic Risk Assessment Large early release frequency
05000335/LER-2025-001, Safety Injection Tank Above Technical Specification Limits	Saint Lucie	26 March 2025	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
05000328/LER-2024-001-01, Reactor Trip Due to an Electrical Trouble Turbine Trip, Update Letter	Sequoyah	26 March 2025	10 CFR 50.73(a)(2)(iv), System Actuation	Reactor Protection System Auxiliary Feedwater
05000336/LER-2024-002-01, For Millstone, Unit 2, Two Main Steam Safety Valves Failed to Lift within the Acceptance Criteria Resulting in a Condition Prohibited by Technical Specifications	Millstone	20 March 2025	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications	Steam Generator Main Steam Safety Valve Decay Heat Removal Control Rod Main Steam	Loss of Offsite Power
05000390/LER-2025-002, Automatic Reactor Trip Due to Main Turbine Trip	Watts Bar	18 March 2025		Feedwater Reactor Protection System Auxiliary Feedwater
05000338/LER-2024-003-01, Loss of Offsite Power Train a Relay Failure During Surveillance Testing	North Anna	18 March 2025	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications	Auxiliary Feedwater	Loss of Offsite Power
05000328/LER-2025-001, Reactor Trip Breakers Opened Due to Group 2 of Control Rod Bank D Failing to Withdraw	Sequoyah	11 March 2025	10 CFR 50.73(b)(3)(iv)(A)	Reactor Protection System Control Rod
05000254/LER-2025-001, Technical Specification 3.6.4.2 Action Not Performed Due to Tagout Boundary Placement Error	Quad Cities	7 March 2025		Secondary containment Primary containment Reactor Building Ventilation
05000250/LER-2024-003-01, Condition Prohibited by Technical Specifications	Turkey Point	6 March 2025	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 Migration	Watts Bar	3 March 2025	10 CFR 50.73(a)(2)(v), Loss of Safety Function	Control Room Emergency Air Temperature Control System
05000440/LER-2024-004, Division 3 Diesel Generator Inoperable Due to Low Output Voltage Resulting in Loss of Safety Function	Perry	24 February 2025	10 CFR 50.73(a)(2)(v), Loss of Safety Function	Reactor Core Isolation Cooling High Pressure Core Spray	Probabilistic Risk Assessment Fuel cladding
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 Specifications	Cooper	20 February 2025	10 CFR 50.73(a)(2)(v), Loss of Safety Function	High Pressure Coolant Injection Core Spray Emergency Core Cooling System Main Condenser Low Pressure Coolant Injection	High Energy Line Break Flow Accelerated Corrosion Through-Wall Leak
05000446/LER-2024-002-01, Turbine Driven Auxiliary Feedwater Pump Unavailable Following Transition from Mode 4 to Mode 3	Comanche Peak	13 February 2025	10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications	Steam Generator Reactor Coolant System Feedwater Auxiliary Feedwater Residual Heat Removal	Loss of Offsite Power
05000338/LER-2024-002-01, Ih EDG Failure to Achieve Rated Speed / Frequency During Surveillance Testing	North Anna	12 February 2025	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications	Emergency Diesel Generator Auxiliary Feedwater	Loss of Offsite Power
05000313/LER-2024-002, ANO Unit 1 Inoperable Containment Isolation Boundary	Arkansas Nuclear	6 February 2025	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		Unanalyzed Condition Time of Discovery Probabilistic Risk Assessment Large early release frequency
05000364/LER-2025-001, Joseph Farley, Unit 2, Containment Isolation Valve Inoperable for Longer than Allowed by Technical Specifications	Farley	5 February 2025	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications	Reactor Coolant System
05000250/LER-2024-004, Unplanned Reactor Scram	Turkey Point	31 January 2025		Reactor Protection System Auxiliary Feedwater
05000395/LER-2024-002-01, (Vcsns), Unit 1, Loss of Control Room Emergency Filtration System	Summer	28 January 2025		Control Room Emergency Filtration System
... further results