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 Entered dateSiteRegionReactor typeEvent description
ENS 5548423 September 2021 18:46:00LimerickNRC Region 1GE-4During planned testing of the Unit 1 HPCI (high pressure coolant injection) system, flow controller oscillations occurred which prevented successful completion of the surveillance test. Operators secured Unit 1 HPCI and declared the system inoperable. HPCI inoperable placed the licensee in a 14-day limiting condition for operation that was extended to 30 days after their risk-informed completion time evaluation was done. The licensee has notified the NRC Resident Inspector.
ENS 554488 September 2021 08:40:00HatchNRC Region 2GE-4At 0159 EDT on 09/08/2021, the HPCI pump discharge valve failed to reopen during a valve surveillance, resulting in the HPCI system being declared INOPERABLE. HPCI does not have a redundant system; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v). Reactor Core Isolation Cooling system and low pressure Emergency Core Cooling Systems were OPERABLE during this time. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5542724 August 2021 16:51:00FitzPatrickNRC Region 1GE-4During an extent of condition review of DC control circuits, it was identified there are additional unprotected DC control circuits which are routed between separate Appendix R fire areas. A postulated fire in one area can cause a short circuit and potentially result in secondary fires or cable fires in other fire areas where the cables are routed. The secondary fires or cable failures degrade the degree of separation for redundant safe shutdown trains and are outside the assumptions of the 10 CFR 50 Appendix R Safe Shutdown Analysis. This condition is reportable in accordance with 10 CFR 50.72(b)(3)(ii)(B). Compensatory actions for affected fire areas have been implemented. Design modifications in the affected control circuits are being developed and will be scheduled to correct this condition.
ENS 5542322 August 2021 12:10:00FermiNRC Region 3GE-4At 0529 EDT on August 22, 2021, HPCI ((High Pressure Coolant Injection System)) was declared inoperable due to receiving the HPCI Inverter Circuit Failure annunciator. The cause of the annunciator was a fuse failure. The cause of the fuse failure is unknown at this time and is under investigation. Concurrent with the HPCI fuse failure was a similar fuse failure within the Division 2 EDG ((emergency diesel generators)) Load Sequencer which renders the Division 2 EDGs inoperable. Relation to the HPCI issue is unknown and is part of the investigation. The RCIC ((Reactor Core Isolation Cooling System)) was verified operable per Tech Spec 3.5.1 E.1. In addition, offsite circuits were verified operable per Tech Spec 3.8.1.B. Division 1 EDGs remain operable. This report is being made pursuant to 10CFR50.72(b)(3)(v)(D) based on an unplanned HPCI inoperability. There was no impact on the health and safety of the public or plant personnel. The Senior NRC Resident Inspector has been notified.
ENS 5542020 August 2021 12:53:00HatchNRC Region 2GE-4A licensed operator failed a pre-access authorization test specified by the FFD testing program test. The employee's access to the plant has been terminated. The NRC Resident Inspector has been notified.
ENS 5540311 August 2021 11:32:00FermiNRC Region 3GE-4At 0634 EDT on August 11, 2021 (high pressure coolant injection) HPCI was declared inoperable due to a pump flow controller problem. The cause of the controller problem is unknown at this time and is under investigation. (Reactor core isolation cooling) RCIC was verified operable per Tech Spec 3.5.1 E.1. This report is being made pursuant to 10CFR50.72(b)(3)(v)(D) based on an unplanned HPCI inoperability. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 553943 August 2021 13:18:00HatchNRC Region 2GE-4At 1026 EDT on 8/3/21, with Unit 1 in MODE 1 at 100 percent power, the reactor automatically tripped due to low reactor water level. The low reactor water level condition was due to a loss of both reactor feed pumps. The cause of the loss of feed pumps is under investigation. Additionally, the low reactor water level resulted in the automatic actuation of High Pressure Coolant Injection (HPCI) and Reactor Core Isolation Cooling (RCIC) systems, and Containment Isolation Valves (CIVs) in multiple systems. All safety systems responded normally. Operations responded and stabilized the plant. Reactor water level is being maintained via RCIC system. Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves. Unit 2 is not affected. Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). It is also reportable under 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the HPCI and RCIC systems and CIVs. There was no impact on the health and safety of the public or plant. The Licensee notified the NRC Resident Inspector. The Unit will proceed to Mode 4 while the cause of the loss of feed pumps is under investigation.
ENS 5537021 July 2021 20:50:00SusquehannaNRC Region 1GE-4At 1826 EDT on July 21, 2021, Susquehanna Steam Electric Station Unit 1 reactor automatically scrammed due to a trip of the Main Turbine. Unit 1 reactor was operating at 100 percent reactor power with no evolutions in progress. The Control Room received indication of a Main Turbine trip with both divisions of RPS (Reactor Protection System) actuated and all control rods inserted. The Reactor Recirculation Pumps tripped on EOC-RPT (end of cycle recirculation pump trip). Reactor water level lowered to +8 inches causing Level 3 (+13 inches) isolations. No ECCS (Emergency Core Cooling Systems) or RCIC (Reactor Core Isolation Cooling system) actuations occurred. The Operations crew subsequently maintained reactor water level at the normal operating band using Reactor Feed Water. The reactor is currently stable in Mode 3 with main condenser available. Investigation into the trip of the Main Turbine is in progress. The NRC Resident Inspector was notified. A voluntary notification to PEMA will be made. This event requires a 4 hour ENS notification in accordance with 10CFR50.72(b)(2)(iv)(B) and an 8 hour ENS notification in accordance with 10CFR50.72(b)(3)(iv)(A) and 10CFR50.72(b)(3)(iv)(B).
ENS 5535715 July 2021 21:36:00FermiNRC Region 3GE-4While preparing for the June 2021 Discharge Monitoring Report (DMR), Environmental was entering data per the lab results that were sent from Pace Analytical for the June DMRs. On June 1, 2021, a National Pollutant Discharge Eliminating System (NPDES) sample was collected at outfall 001A to test for copper, there is a NPDES permit condition to monitor for copper on a quarterly basis. The lab report was returned to Fermi Environmental on June 15, 2021. The results came back at 41.2 micrograms/liter. Fermi's NPDES permit maximum limit is 40 micrograms/liter for outfall 001A. Due to the June 1, 2021 sample exceeding the permit limit, a second sample was collected on June 21, 2021 as a verification sample and the copper results came back July 13, 2021. Those results came back at 5.9 micrograms/liter which is within the permit limit. Environmental was aware of the June 1, 2021 copper exceedance limit but failed to recognize the reporting requirement at the time of the discovery because it was thought that the exceedance would be reported through the DMR submittal. The June DMRs are due on July 20, 2021. At approximately 1740 EDT on July 15, 2021, a Fermi environmental engineer was preparing and reviewing the Discharge Monitoring Report and identified that a recent sample result for outfall 001A was outside of the NPDES permit limit for Copper. The Copper sample result was 41.2 micrograms/liter with a limit of 40 micrograms/liter. Subsequent discussions with Environmental personnel determined that this issue should be reported to the state of Michigan Department of Environment, Great Lakes and Energy (EGLE). A discussion is planned with EGLE on July 16, 2021. This notification is being made pursuant to 10 CFR 50.72(b)(2)(xi) based on the planned notification to EGLE. The licensee notified the NRC Resident Inspector.
ENS 553458 July 2021 20:07:00LimerickNRC Region 1GE-4This 60-Day telephone notification is being made per the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) to describe an invalid actuation of containment isolation signal affecting more than one system. On May 13, 2021, during the restoration of the Unit 2 Refuel Floor High Radiation Isolation Logic an invalid isolation signal was received. The condition requiring an isolation signal was verified not to be present prior to restoring the logic; however, it was not recognized that a previous isolation signal was latched in and had not been reset. When the isolation logic was restored, the Primary Containment Isolation System (PCIS) isolated on the invalid signal. The systems successfully completed the isolation per the plant design and plant configuration. The following systems actuated due to the Unit 2 PCIS Group 6C Isolation: - Isolation of Containment Hydrogen and Oxygen Sampling Valves, - Start of the 2A Reactor Enclosure Recirculation System, - Trip of the Units 1 and 2 Refuel Floor HVAC, - Start of the A and B Trains of Standby Gas Treatment Systems. The NRC Resident Inspector was notified.
ENS 5530311 June 2021 18:06:00HatchNRC Region 2GE-4

At 1710 EDT on June 11, 2021, a Technical Specification required shutdown was initiated at Plant Hatch Unit 1. Technical Specification Condition 3.4.4.B unidentified LEAKAGE increase not within limits, was entered due to a greater than 2 gpm increase in unidentified LEAKAGE within the previous 24 hour period in MODE 1. This specification was entered on June 11, 2021, at 1615 EDT with a REQUIRED ACTION to restore leakage increase within limits within 4 hours. This REQUIRED ACTION could not be completed within the COMPLETION TIME; therefore, a Technical Specification required shutdown was initiated, and this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(i). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.

  • * * RETRACTION ON 6/17/2021 AT 1309 FROM JASON BUTLER TO JEFFREY WHITED * * *

Upon further review of the leakage rates, it was determined that at 1900 EDT on 6/11/2021 the drywell floor drain unidentified leakage increased greater than 2 gpm within the previous 24 hours while in MODE 1. Technical Specification (TS) 3.4.4.B was entered to reduce leakage increase to within limits within 4 hours. At 2000 EDT on 6/11/2021 unidentified leakage was reduced below the 2 gpm increase within the previous 24 hours due to actions taken to lower reactor power and pressure. Therefore, the TS required shutdown per TS 3.4.4.C was not applicable. Thus Event Report 55303 is being retracted. The NRC resident has been notified of the retraction. Notified R2DO (Miller).

ENS 552871 June 2021 17:46:00Browns FerryNRC Region 2GE-4This 60-day telephone notification is being made per the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation of the 2A Reactor Protection System (RPS). On April 1, 2021, at 1302 (CDT), Browns Ferry Unit 2, 2A RPS (Motor Generator) MG set tripped causing a half scram. Unit 2 experienced an unexpected trip of the 2A RPS MG Set that resulted in automatic Primary Containment Isolation System (PCIS) Group 2, 3, 6, and 8 isolations and Trains A, B, and C Standby Gas Treatment (SGT) and Train A Control Room Emergency Ventilation (CREV) starts. At the time of the event, Unit 2 was in a refueling outage and the rods were already fully inserted. All systems responded as expected. Plant conditions which initiate PCIS Group 2 actuations are Reactor Vessel Low Water Level (Level 3) or High Drywell Pressure. The PCIS Group 3 actuations are initiated by Reactor Vessel Low Water Level (Level 3) or Reactor Water Cleanup Area High Temperature. The PCIS Group 6 actuations are initiated by Reactor Vessel Low Water Level (Level 3), High Drywell Pressure, or Reactor Building Ventilation Exhaust High Radiation (Reactor Zone or Refuel Zone). The PCIS Group 8 actuations are initiated by Low Reactor Vessel Water Level (Level 3) or High Drywell Pressure. At the time of the event, these conditions did not exist; therefore, the actuation of the PCIS was invalid. Based on the troubleshooting conducted, the cause was determined to be a loose wiring connection in the motor circuit. The lugs were replaced with ring lugs. Operations reset the 2A RPS Half Scram and PCIS in accordance with 2-AOI-99-1 on April 1, 2021, at 1324 CDT thus correcting the condition and returning RPS to service. There were no safety consequences or impact to the health and safety of the public as a result of this event. This event was entered into the Corrective Action Program as Condition Report 1683358. The NRC Resident Inspector has been notified of this event.
ENS 5526117 May 2021 13:12:00Peach BottomNRC Region 1GE-4

(Peach Bottom Atomic Power Station declared an unusual event due to a) "receipt of a single fire alarm in the Unit 2 drywell and the existence of the fire not verified in less than 30 minutes of alarm receipt." The NRC Resident Inspector and State and Local Authorities were notified. Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email).

  • * * UPDATE ON 5/17/21 AT 1423 EDT FROM BRETT HENRY TO HOWIE CROUCH * * *

At 1355 EDT, the licensee terminated the notification of unusual event. The basis for termination was that the smoke has dissipated and there were no signs of fire. The licensee notified State and Local Authorities and the NRC Resident Inspector. Notified R1DO (Grieves), NRR EO (Miller), and IRD MOC (Grant). Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS Nuclear SSA (email), FEMA NRCC THD (email) and FEMA NRCC SASC (email).

  • * * RETRACTION ON 6/8/2021 AT 1249 EDT FROM JAMES BROWN TO DONALD NORWOOD * * *

Peach Bottom Atomic Power Station is retracting notification EN 55261, 'Peach Bottom - Unusual Event,' based on the following additional information not available at the time of the notification: Following a Unit 2 drywell inspection, analysis of temperature data, and evaluation of equipment in operation; it was concluded that a fire did not exist. The smoke's most likely apparent cause was the result of heating residual oil/grease in the drywell. Peach Bottom reported the condition and entry into the UE initially based on the available information at the time and to ensure timeliness with emergency declaration and reporting notification requirements. The licensee has notified the NRC Resident Inspector. Notified R1DO (Ferdas).

ENS 552313 May 2021 15:39:00FermiNRC Region 3GE-4At 0930 EDT on 5/3/2021, it was determined that during entries into the Fermi 2 Reactor Building Steam Tunnel (RBST) on 4/17/2021, 4/18/2021, and 4/21/2021 that the door was not controlled according to site procedures. The RBST door is credited as a hazard barrier for various high-energy line break (HELB) scenarios. On the identified dates, the RBST door was left open for brief periods during maintenance related activities in the RBST. This condition is not bounded by existing analyses as the door is assumed to be closed throughout a HELB event. The time period that the door was open was less than one hour in each case, as stay times in the room are inherently limited by industrial and radiological conditions. Individuals remained in the area to close the door if needed, but existing analyses do not address the ability to perform those actions under all HELB scenarios. There is no impact to the health and safety of the public or plant personnel as the door is currently closed and latched and access into the area has been restricted to normal ingress and egress per site procedures, which ensures consistency with existing analyses. Therefore, this event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(ii)(B). Investigation into the cause is ongoing. Preliminary review of the extent of this condition identified entries into the RBST on other occasions during the past three years where the conditions may also have not been bounded by existing analyses. The additional occasions where the door may have been held open were on 9/22/2018 (MODE 3), 10/26/2018 (MODE 1 ), 11/2/2018 (MODE 1), and 3/21/2020 (MODE 3). Each of these instances was also less than one hour with the exception of the occurrence beginning on 10/26/2018 which lasted approximately 10 hours to support packing leak repairs on a HPCI (High Pressure Coolant Injection) Outboard Isolation Valve. The licensee notified the NRC Resident Inspector.
ENS 5522430 April 2021 07:38:00Peach BottomNRC Region 1GE-4On 4/29/21 at 2354 (EDT), an alarm was received for U2 HPCI Inverter Power Failure. (It was) identified that the High Pressure Coolant Injection (HPCI) flow controller had lost power due to a failure of an inverter. Without the flow controller, HPCI would not auto start to mitigate the consequences of an accident; thus, HPCI was declared inoperable. All other emergency core cooling systems and reactor core isolation cooling (RCIC) system remain operable. HPCI is a single train system with no redundant equipment in the same system; therefore, this failure is reportable as an event or condition that could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident per 10CFR50.72(b)(3)(v)(d). The NRC Resident has been informed of this notification.
ENS 5520020 April 2021 15:36:00Browns FerryNRC Region 2GE-4A non-licensed, employee supervisor had a confirmed positive for alcohol during a random fitness-for-duty test. The employee's access to the plant has been terminated. The licensee notified the NRC Resident Inspector.
ENS 5519114 April 2021 13:00:00BrunswickNRC Region 2GE-4This 60-day optional telephone notification is being made in lieu of an LER submittal as allowed by 10 CFR 50.73(a)(1). This notification is made pursuant to the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) for an invalid actuation of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B). At approximately 1507 EDT on February 17, 2021, during performance of isolation logic periodic testing associated with Primary Containment Isolation System Groups 2 and 6, an invalid actuation of Group 6 Primary Containment Isolation Valves (PCIVs) (i.e., Containment Atmospheric Control/Monitoring and Post Accident Sampling isolation valves) occurred. The Group 6 isolation signal resulted from the reactor building ventilation radiation monitor `B' Channel exceeding the setpoint value. This condition likely resulted from the radiation monitor electronics being impacted by humidity levels, which exceeded the instrument design requirements that developed in the area over time as a result of the Unit 2 reactor building ventilation being secured per the test procedure. The `A' Channel, located in the same plenum, remained steady and below the setpoint value through the entire event. This, along with readings made by a Radiation Protection Technician, confirmed that there was no actual high radiation condition in the reactor building exhaust. Upon returning Unit 2 reactor building ventilation to service, the `B' Channel readings returned to be consistent with the `A' Channel. The PCIVs functioned successfully and the actuation was complete. The actuation was not initiated in response to actual plant conditions, it was not an intentional manual initiation, and there were no parameters satisfying the requirements for initiation of the system. Therefore, this event has been determined to be an invalid actuation. This event did not result in any adverse impact to the health and safety of the public. The NRC Resident Inspector was notified.
ENS 5518712 April 2021 09:17:00HatchNRC Region 2GE-4At 2323 EST on 02/12/2021, with Unit 2 in Mode 5 at zero percent power, an actuation of the Group I containment isolation logic occurred during fluid flushing of turbine stop valves. The reason for the actuation was due to a maintenance activity resulting in turbine stop valve movement with no condenser vacuum which is a Group I isolation signal. Two Group I isolation valves, 2B31F019 and 2B31F020, reactor water sample valves, automatically isolated as designed when the system actuation signal was received. The other Group I valves had already been removed from service as part of the refueling outage schedule. This event is being reported in accordance with 10 CFR 50.73(a)(2)(iv)(A) as an event that results in an invalid actuation of the Group I containment isolation system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5518812 April 2021 09:17:00HatchNRC Region 2GE-4At 2320 EST on 02/17/2021, with Unit 2 in Mode 5 at zero percent power, an actuation of the Group 2 containment isolation logic occurred on the inboard valves. The reason for the actuation was most likely due to air entrapment in reactor water level sensing lines following maintenance. Group 2 inboard isolation valves in the drywell floor and equipment drain system and the fission product monitor system automatically isolated as designed. As a corrective action, the variable leg and reference leg of the instrumentation were backfilled with water to ensure all air was removed from the line. This event is being reported in accordance with 10 CFR 50.73(a)(2)(iv)(A) as an event that results in an invalid actuation of the Group 2 containment isolation system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5516030 March 2021 14:00:00FermiNRC Region 3GE-4At 1058 EDT on 3/30/2021, during routine pump down activities from the sites Equalization Basin, open to the environment (consisting of groundwater and runnoff), to a sanitary system manhole, there was a backflow from the sanitary system to the environment (nearby grassy area). The total amount of overflow is estimated to be 150 gallons. Fermi 2 Environment is currently investigating and clean-up is in progress and the backflow has stopped. The cause of the backflow is under investigation. As a result of the backflow reaching the environment, reports are being made to the Michigan Department of Environment, Great Lakes, and Energy (EGLE), the Monroe County Health Department, and the local news media. Since these reports are in the process of being made, this is considered a News Release or Notification to Other Government Agencies, therefore this event is reportable under 10 CFR 50.72(b)(2)(xi). The licensee has notified the NRC Resident Inspector.
ENS 5514822 March 2021 13:16:00SusquehannaNRC Region 1GE-4At 1005 EDT on 3/22/2021, the control room was notified of a personal medical event in the Radiologically Controlled Area. An ambulance entered Susquehanna plant property at 1019 and exited at 1028 to transport the individual to a local hospital. Ambulance did not enter the Protected Area. The individual was considered potentially contaminated since a complete frisk could not be performed prior to transport. Following transportation to a local hospital, Radiation Protection (RP) technicians confirmed the individual and ambulance were not contaminated. This event is reportable under 10CFR50.72(b)(3)(xii). An Event of Potential Public Interest (EPPI) was made to the Pennsylvania Emergency Management Agency (PEMA) due to an emergency vehicle accessing plant property. The NRC Resident Inspector was notified.
ENS 551289 March 2021 08:08:00SusquehannaNRC Region 1GE-4At 0313 EST on March 9th, 2021, during performance of Unit 1 High Pressure Coolant Injection (HPCI) valve exercising, the inboard vacuum breaker isolation valve did not stroke closed as expected, but remained mid-position. The affected penetration of primary containment was isolated by closing the outboard HPCI vacuum breaker isolation valve. This results in an unplanned inoperability of the Unit 1 HPCI system. This is being reported as a loss of an entire safety function condition in accordance with 10CFR50.72(b)(3)(v)(D). The licensee notified the NRC Resident Inspector. Unit 1 is in a 14-day LCO for Tech Spec 3.5.1(d), HPCI inoperability. Tech Spec 3.6.1.3(a), Containment Penetration Valve, was completed with closing the outboard HPCI vacuum breaker isolation valve. The Units are in a normal offsite power line-up.
ENS 550989 February 2021 10:35:00CooperNRC Region 4GE-4On February 9, 2021, at 0153 CST, Cooper Nuclear Station experienced a spike in Secondary Containment differential pressure which exceeded the Technical Specifications Surveillance Requirements 3.6.4.1.1 limit of -0.25 inches of water gauge. Secondary Containment differential pressure oscillated coincident with barometric pressure oscillations. Three additional spikes occurred which exceed the Technical Specification limit. The duration of each spike was less than one minute. The last spike occurred at 0232 CST. Secondary Containment differential pressure has restored to Technical Specification limits and further investigation is ongoing. This unplanned Secondary Containment inoperability constitutes a condition reportable under 10CFR50.72(b)(3)(v)(C) and (D), "An event or condition that at the time of discovery could have prevented the fulfillment of the safety function of (Structures, Systems, and Components) SSCs that are needed to control the release of radioactive material and mitigate the consequences of an accident. The NRC Senior Resident Inspector has been informed.
ENS 5500016 November 2020 12:13:00LimerickNRC Region 1GE-4During normal plant start up on Limerick Unit 1, reactor pressure was raised above 200 psig prior to unisolating the Unit 1 high pressure coolant injection system (HPCI) which remained inoperable. Per TS 3.5.1, HPCI is required to be operable in Mode 2 above 200 psig. HPCI has since been restored to operable. The NRC Resident Inspector has been notified.
ENS 5499613 November 2020 05:32:00LimerickNRC Region 1GE-4At 0245 EST on November 13, 2020, the Limerick Unit 1 reactor automatically scrammed on a valid Reactor High Pressure signal (1096psig). The Reactor High Pressure signal was caused by the closure of the 1B Inboard Main Steam Isolation Valve (MSIV), causing reactor pressure to rise, exceeding the Reactor Protection System (RPS) setpoint of 1096psig. The shutdown was normal and the plant is stable in Hot Shutdown with normal pressure control via the Main Steam Bypass Valves to the Main Condenser and normal level control using the Feedwater System. The closure of the 1B Inboard MSIV appears to have been caused by a loss of Primary Containment Instrument Gas (PCIG) pneumatic supply to the valve. The licensee notified the NRC Resident Inspector, and will be notifying Berks, Chester, and Montgomery Counties, as well as the Pennsylvania Emergency Management Agency.
ENS 549835 November 2020 06:32:00Browns FerryNRC Region 2GE-4

At 2150 CST on 11/04/2020, it was discovered that Unit 1 High Pressure Coolant Injection System (HPCI) was INOPERABLE; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v), as an event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. During performance of 1-SR-3.5.1.7, HPCI Main and Booster Pump Set Developed Head and Flow Rate Test at Rated Reactor Pressure, Unit 1 HPCI was manually tripped by the control room operator due to local report of excessive shaking of the cooling water supply from the booster pump line. There was no impact to the safety of the public or plant personnel. The NRC Resident Inspector has been notified. CR 1650042 documents this condition in the Corrective Action Program. The Unit is in a 14-day LCO 3.5.1(c). The RCIC System is operable.

  • * * RETRACTION FROM MARK ACKER TO HOWIE CROUCH AT 1607 EST ON 12/29/2020 * * *

ENS Event number 54983, made on 11/05/2020 is being retracted. NRC notification 54983 was made to ensure that the Eight-Hour Non-Emergency reporting requirements of 10 CFR 50.72 were met when Unit 1 HPCI was manually tripped by the control room operator due to a local report for excessive shaking of the cooling water supply from the booster pump line. A subsequent engineering evaluation concluded on 11/06/2020 there was reasonable assurance of operability with no additional intrusive maintenance performed and that the condition was bounded by a previous evaluation documented in (Condition Report) CR 1347736. As such, the circumstances discussed in the report did not result in any condition that at the time of discovery could have prevented the fulfillment of the safety function of structures of the system that are needed to mitigate the consequences of an accident. Therefore, this event is not reportable under 10 CFR 50.72(b)(3)(v). TVA's evaluation of this event is documented in the corrective action program. The licensee has notified the NRC Resident Inspector. Notified R2DO (Miller).

ENS 549761 November 2020 09:34:00CooperNRC Region 4GE-4On November 1, 2020, at 0534 CST the reactor was manually scrammed due to an un-isolable leak on the Turbine High Pressure Fluid System. Initial power level when the leak was identified was 100 percent. Power was lowered commencing at 0525 in accordance with shutdown procedures. The Reactor Operator scrammed the reactor at 0534 from approximately 75 percent power. Following the scram, Reactor vessel water level lowered to approximately -20 inches on the Wide Range Instruments, and was subsequently recovered to normal post scram range (approximately 36 inches) using the Reactor Feedwater system. Group 2 Isolation occurred due to Reactor vessel level reaching the isolation setpoint (3 inches). The plant is stable in MODE 3 and proceeding to cold shutdown. The Main Condenser remained available throughout the evolution and condenser vacuum is currently being maintained by the Mechanical Vacuum Pumps. Pressure is being controlled using the steam line drains to the main condenser. All control rods fully inserted and there were no complications. All systems responded as designed. The Turbine High Pressure Fluid System has been secured. This event is reportable under 10 CFR 50.72(b)(2)(iv)(B) due to RPS Actuation-Critical and 50.72(b)(3)(iv)(A) Valid Specified System Actuation. The licensee has notified the NRC Resident Inspector.
ENS 5497129 October 2020 15:12:00Peach BottomNRC Region 1GE-4At 1030 EDT on Thursday, October 29, 2020, during the performance of Peach Bottom Atomic Power Station leakage testing of the reactor pressure vessel and associated piping, a through-wall leak (non-isolable) was identified on an instrument line connected to the N16A nozzle. The reactor will be maintained shutdown until pipe repairs and testing are complete. The NRC resident inspector has been informed.
ENS 5342927 May 2018 12:42:00FermiNRC Region 3GE-4On May 27, 2018 at 0630 EDT, the Reactor Water Cleanup (RWCU) System Isolation Differential Flow - High function was declared inoperable as a result of indicating downscale. This condition would have prevented the primary containment isolation valves for the RWCU system from automatically isolating on a high differential flow instrumentation signal. At 0753, RWCU was shutdown and the affected penetration flow paths were isolated in accordance with station procedures per Fermi Technical Specifications. The cause of the event is under investigation. There was no radiological release associated with this event. All other RWCU primary containment isolation instrumentation functions remained operable and the associated RWCU system primary containment isolation valves were capable of being remotely closed by the control room operators throughout the event. However, the condition is reportable pursuant to 10 CFR 50.72(b)(3)(v)(C) and 10 CFR 50.72(b)(3)(v)(D). The NRC Resident Inspector was notified.
ENS 533854 May 2018 16:20:00FermiNRC Region 3GE-4At 1412 EDT, a portable chemical toilet was found tipped over. Approximately 1 gallon of contents spilled to gravel only. A notification to the Michigan Department of Environmental Quality and local health department is required, as well as a press release. This event is being reported pursuant to 10CFR50.72(b)(2)(xi). The licensee will notify the NRC Resident Inspector.
ENS 5335220 April 2018 16:05:00SusquehannaNRC Region 1GE-4A non-licensed supervisory contract worker was found in violation of the Fitness for Duty Program. The individual's access to the plant has been terminated. The licensee notified the NRC Resident Inspector.
ENS 5334117 April 2018 16:29:00LimerickNRC Region 1GE-4Unit 1 HPCI (High Pressure Coolant Injection) was declared inoperable due to a Main Pump seal leak that was identified during surveillance testing. Unit 1 HPCI was declared inoperable at 1030 EDT. HPCI was secured and was manually re-aligned to an available status. At the time of this notification, repairs have been completed and the licensee is making preparations to re-perform the surveillance. The licensee has notified the NRC Resident Inspector.
ENS 5334017 April 2018 12:02:00Browns FerryNRC Region 2GE-4At 0416 CDT on April 17, 2018, the High Pressure Coolant Injection System (HPCI) was isolated due to a water side leak from the gland seal condenser. Unit 1 HPCI remains inoperable pending repairs to the gland seal condenser. This condition is being reported pursuant to 10 CFR 50.72(b)(3)(V)(D), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident.' This is also reportable as a 60-day written report in accordance with 10 CFR 50.73(a)(2)(V)(D). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified of this event.
ENS 5333614 April 2018 14:34:00FermiNRC Region 3GE-4

At 1040 EDT, Fermi 2 automatically scrammed on RPV (Reactor Pressure Vessel) Level 3 following a loss of the Division 1 Station System Transformer (SST) #64. All control rods fully inserted. HPCI (High Pressure Coolant Injection) and RCIC (Reactor Core Isolation Cooling) automatically started as designed on Reactor Water Level (RWL) 2 and restored RWL. The lowest RWL reached was 101.8 inches (above Top of Active Fuel). HPCI injected for approximately 35 seconds. RWL is currently being maintained in the normal level band with RCIC. No Safety Relief Valves (SRVs) actuated. All isolations and actuations for RWL 3 and 2 occurred as expected. Investigation into loss of SST #64 continues. At the time of the scram, all Emergency Core Cooling Systems (ECCS) and Emergency Diesel Generators (EDGs) were operable, and no safety related equipment was out of service. This report is being made in accordance with 10CFR50.72(b)(2)(iv)(A), any event that results in ECCS discharge into the reactor coolant system as a result of a valid signal and 10CFR50.72(b)(2)(iv)(B), any event that results in the actuation of the Reactor Protection System (RPS) when the reactor is critical. Following the loss of power and reactor scram, the Division 2 EECW (Emergency Equipment Cooling Water) Temperature Control Valve (TCV) controller was in Emergency Manual and maintaining max cooling. Operators placed the controller in Auto and the TCV is controlling normally. The NRC Senior Resident has been notified. Decay heat is being removed via Division 2 steam dumps to the condenser. The plant is in a modified shutdown electric lineup with offsite power available and stable. Emergency diesel generators did automatically start and load.

  • * * UPDATE ON 4/14/2018 AT 1838 EDT FROM JEFF MYERS TO HOWIE CROUCH * * *

This update provides additional clarification of the applicable reporting criteria for this event associated with Primary Containment Isolation Actuations. All isolations and actuations for RWL (Groups 4, 13, and 15) and RWL 2 (Groups 2, 10, 11, 12, 14, 16, 17, and 18) occurred as expected. This report is also being made in accordance with 10CFR50.72(b)(3)(iv)(A), any event or condition that results in valid actuation of any systems listed in paragraph (b)(3)(iv)(B): RPS, HPCI, and RCIC. RPV pressure is being maintained by the bypass valves to the main condenser. All actuations that occurred were fully completed and restored. The licensee notified the NRC Resident Inspector. Notified R3DO (Stone).

  • * * UPDATE ON 4/15/2018 AT 1950 EDT FROM KELLEY BELENKY TO DAVID AIRD * * *

This update provides additional information regarding the specified system actuations and an additional applicable reporting criteria. The loss of Division 1 Station System Transformer (SST) #64 at 1040 EDT on 4/14/2018 resulted in the automatic initiation of Emergency Diesel Generators (EDG) 11 and 12. The EDGs started as expected and continue to supply their associated busses. This is reportable pursuant to 10CFR50.72(b)(3)(iv)(A), as an event or condition that resulted in a valid actuation of any system listed in paragraph (b)(3)(iv)(B), including EDGs. In addition, the loss of the Division 1 SST #64 resulted in the expected transfer from the normal to alternate power source for the Low Pressure Coolant Injection (LPCI) swing bus, rendering LPCI loop select inoperable. The alternate power source continued to energize the LPCI swing bus throughout the event until the system was realigned to the normal power source at 1239 EDT on 4/14/2018. This condition is reportable pursuant to 10CFR50.72(b)(3)(v)(D). The licensee notified the NRC Resident Inspector. Notified R3DO (Stone).

ENS 533197 April 2018 12:10:00BrunswickNRC Region 2GE-4

On April 7, 2018, at 0836 EDT, with Unit 1 in Mode 1 at approximately 100 percent power, the reactor automatically tripped during testing of the stator cooling system. The trip was uncomplicated with all systems responding normally. No safety-related equipment was inoperable at the time of the event. 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).

Operations responded using Emergency Operating Procedures and stabilized the plant in Mode 3. Reactor water level being maintained via normal feedwater system. Decay heat is being removed through the bypass valves.

Reactor water level reached low level 1 (LL1) as a result of the reactor trip. The LL1 signal causes a Group 2 (i.e., floor and equipment drain isolation valves), Group 6 (i.e., monitoring and sampling isolation valves) and Group 8 (i.e., shutdown cooling isolation valves) isolations. The LL1 isolations occurred as designed; the Group 8 valves were closed at the time of the event. Due to the Primary Containment Isolation System (PCIS) actuation, this event is also being reported as an eight-hour, non-emergency notification in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the PCIS. Unit 2 was not affected. There was no impact on the health and safety of the public or plant personnel. The safety significance of this event is minimal. The automatic reactor trip was not complicated and all safety-related systems operated as designed. Investigation of the cause of the Reactor Protection System actuation is in progress. The licensee notified the NRC Resident Inspector.

ENS 533103 April 2018 02:53:00SusquehannaNRC Region 1GE-4On April 3, 2018 at 0019 (EDT), the Susquehanna control room received indication that a loss of Secondary Containment Zone 3 differential pressure had occurred. Control room operators noted the loss following completion of surveillance testing. The cause is under investigation. Zone 3 differential pressure was restored to greater than 0.25 inches WC (water column) at 0145 (EDT). Zone 3 differential pressures being less than 0.25 inches WC constitutes a loss of Secondary Containment based on not meeting requirements of SR (Surveillance Requirement) 3.6.4.1.1. This event is being reported under 10 CFR 50.72(b)(3)(v)(C) and per the guidance of NUREG-1022, Revision 3, Section 3.2.7, as a loss of a Safety Function. There is no redundant Susquehanna Secondary Containment system. The NRC Resident Inspector has been notified.
ENS 5330029 March 2018 22:28:00Browns FerryNRC Region 2GE-4At 1344 on March 29, 2018, it was determined (engineering evaluation) that an unanalyzed condition that significantly degraded plant safety previously existed. During a postulated control room abandonment due to a fire, and concurrent with a Loss of Offsite Power (LOOP), the required number of Emergency Equipment Cooling Water (EECW) pumps would not have been available from 10/28/2015 to 3/10/2018. On March 8, 2018, during relay functional testing it was discovered that the C3 Emergency Equipment Cooling Water (EECW) pump closing springs did not recharge with the breaker transfer switch in emergency. On August 23, 2012, a wire modification was performed that contained a drawing error resulting in wire placement on the incorrect connection points for the C3 EECW pump. On March 10, 2018, the C3 EECW pump breaker wiring was corrected and subsequent testing was completed satisfactorily. Prior to 10/28/2015, Brown's Ferry Nuclear Plant (BFN) adhered to Appendix R fire protection requirements which did not credit the C3 EECW pump for fire protection from the backup control location. On 10/28/2015, BFN transitioned to National Fire Protection Association (NFPA) 805 fire protection requirements which takes credit for the C3 EECW pump from the backup control location. This condition is being reported pursuant to 10 CFR 50.72(b)(3)(ii)(B), 'Any event or condition that results in the nuclear power plant being in an unanalyzed condition that significantly degrades plant safety'. This is also reportable as a 60-day written report in accordance with 10 CFR 50.73(a)(2)(ii)(B). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified of this event.
ENS 5326918 March 2018 16:16:00Browns FerryNRC Region 2GE-4At 1158 CDT on March 18, 2018, the Unit 1 reactor automatically scrammed due to a Reactor Protection System (RPS) signal generated from High Reactor Steam Dome Pressure in response to Turbine Control Valve Closure. The reactor had been operating at 100 percent power. Investigation is in progress. All control rods fully inserted into the core. Main Steam Isolation Valves remained open with Main Steam Relief Valves (MSRVs) operating on the initial transient as expected. Main Turbine Bypass Valves are currently controlling reactor pressure. Reactor Feedwater pumps remained in service to control reactor water level. Primary Containment Isolation Signals Groups 2, 3, 6, and 8 containment isolation and initiation signals were received. Upon receipt of these signals all required components actuated as required. All safety system operated as expected. At no time was public health and safety at risk. This event is reportable within 4 hours per 10 CFR 50.72(b)(2)(iv)(B) 'any event or condition that results in actuation of the Reactor Protection System (RPS) when the reactor is critical except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation.' It is also reportable within 8 hours per 10 CFR 50.72(b)(3)(iv)(A) 'any event or condition that results in valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B) of this section, except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation' and requires an LER within 60 days per 10 CFR 50.73(a)(2)(iv)(A). The NRC Resident Inspector has been notified.
ENS 5326515 March 2018 22:08:00Peach BottomNRC Region 1GE-4At 1524 (EDT) on Thursday, March 15, 2018, Operations was notified of a failure to meet Appendix R requirements for Peach Bottom Atomic Power Station (PBAPS) Unit 2 and Unit 3. Valves associated with the feedwater system for both units were not properly considered as Hi-Lo Pressure interface valves as required by the Appendix R program. This results in the susceptibility to a hot short condition that could open valves, diverting flow from the reactor, damage piping and prevent injection. U3 (Unit 3) Fire Safe Shutdown Credited Reactor Core Isolation Cooling (RCIC) System is affected. U2 (Unit 2) is affected by a potential leak path through the Reactor Water Cleanup system. This event is being reported as an occurrence of an event or condition that results in the nuclear power plant being in an unanalyzed condition that significantly degrades plant safety under 10 CFR 50.72(b)(3)(ii). The Station (PBAPS) is performing hourly fire watches for the impacted areas and is also evaluating this condition for corrective action. The licensee notified the NRC Resident Inspector.
ENS 5326115 March 2018 01:39:00CooperNRC Region 4GE-4

At approximately 1711 CDT on 14 MAR 2018, Cooper Nuclear Station was notified by the National Weather Service that the Shubert radio transmission tower was not functioning. This affects the tone alert radios used to notify the public in event of an emergency condition. This condition is reportable under 10CFR50.72(b)(3)(xiii). A backup notification method is available and will be utilized for notifications if needed. The local telephone company is providing troubleshooting and repair services. A return to service time for the Shubert tower is not currently available. The NRC Senior Resident Inspector has been informed. The issue was identified during periodic maintenance. The licensee notified all counties within the 10 mile Emergency Planning Zone.

  • * * UPDATE ON 3/19/2018 AT 1720 EDT FROM STEVE WHEELER TO DONG PARK * * *

This is a follow up notification to update the status of the Shubert radio transmission tower that was reported to be out of service on March 14th per EN53261. The tower was restored to service and determined to be functional at 0759 (CDT) on March 19th, 2018. The licensee notified the NRC Resident Inspector. Notified R4DO (Groom).

ENS 5325612 March 2018 14:34:00SusquehannaNRC Region 1GE-4A non-licensed supervisor tested positive for alcohol during pre-access screening. The individual's access to the plant was denied. The NRC Resident Inspector has been notified.
ENS 5325310 March 2018 13:54:00CooperNRC Region 4GE-4HPCI (High Pressure Coolant Injection) was removed from service (unplanned) on 3/10/2018 at time 0709 (CST) by closing HPCI-MO-15, STEAM SUPPLY INBOARD ISOLATION. The inboard steam supply isolation valve is inside Primary Containment. The steam supply valve was closed in an effort to isolate (unidentified) leakage to Primary Containment from a suspected packing leak from HPCI-MO-15. After closing the HPCI-MO-15, Reactor Coolant System Leakage parameters returned to within Technical Specification (TS) LCO (Limiting Condition of Operations) 3.4.4 limits. Entered into Technical Specification LCO 3.5.1 Condition C - HPCI System Inoperable. Required Actions for Condition 'C' are to verify by administrative means RCIC (Reactor Core Isolation Cooling) System is operable within 1 hour and restore HPCI System to operable status within 14 days. RCIC was verified operable by administrative means concurrent with declaration of HPCI inoperable. Normal plant shutdown activities are being planned (for 03/11/2018 at 1200 CDT) to support entry into Primary Containment to initiate any necessary repairs. HPCI is a single train safety system. This report is submitted as a condition that at time of discovery could prevent the fulfillment of the safety function of an SSC (System, Structure, or Component) needed to mitigate the consequences of an accident. This condition has been entered into the CNS (Cooper Nuclear Station) Corrective Action Program. CR-CNS-2018-01346 LCO 3.4.4 was entered during unplanned maintenance of the HPCI system. When the HPCI-MO-15 was cycled from closed to open, unidentified leakage in the containment increased above 2 gallons per minute (gpm) in less than a 24 hour period. Also, total unidentified leakage exceeded 5 gpm. The licensee closed the HPCI-MO-15 valve resulting in a decrease in unidentified leakage below TS shutdown limit. The NRC Resident Inspector was notified.
ENS 532477 March 2018 12:25:00Browns FerryNRC Region 2GE-4

The licensee declared an Unusual Event based on Emergency Action Level (EAL) 6.7.U and entry into the site Security Plan. All required actions or compensatory measures have been completed. The Notice of Unusual Event was terminated at 1142 CST. There was no impact to the operation of any of the units at the Browns Ferry site. The licensee has notified the NRC Senior Resident Inspector. See EN #53248. Notified DHS SWO, FEMA Ops, DHS NICC, FEMA NWC (email) and NuclearSSA (email).

  • * * UPDATE AT 1816 EST ON 03/07/2018 FROM DAVID RENN TO JEFF HERRERA * * *

The licensee provided additional information regarding the event. Notified the R2DO (Musser), IRD MOC (Gott), NRR EO (Miller).

ENS 532361 March 2018 13:53:00FermiNRC Region 3GE-4A non-licensed, supervisory employee was determined to be under the influence of alcohol during a random test. The employee's unescorted access was terminated. The NRC Resident Inspector has been notified.
ENS 5321415 February 2018 17:36:00FermiNRC Region 3GE-4A can of alcohol (8.4 ounces) was discovered unopened in a refrigerator inside the protected area. Site security took possession of the can of alcohol. The owner of the can of alcohol is unknown. This report is being made under 10 CFR 26.719(b)(1) as a 24 hour telephone notification. The can had an expiration date of April 2017. The licensee notified the NRC Resident Inspector and the Regional Inspector.
ENS 5320211 February 2018 23:36:00SusquehannaNRC Region 1GE-4On February 11, 2018 at 2203 (EST), the Susquehanna Control Room received indication that a loss of Secondary Containment Zone 2 differential pressure (DP) had occurred. Control Room operators noted a differential pressure of <.25" WC (inches Water Column) for several seconds. System DP was restored to normal in 1 minute. The cause of the pressure swings is under investigation. Zone 2 differential pressures being less than 0.25" WC constitutes a loss of Secondary Containment based on not meeting requirements of SR 3.6.4.1.1. This event is being reported under 10 CFR 50.72(b)(3)(v)(c) and per the guidance of NUREG 1022 Rev 3 section 3.2.7 as a loss of a Safety Function. There is no redundant Susquehanna Secondary Containment system. The licensee notified the NRC Resident Inspector.
ENS 5317822 January 2018 15:09:00FermiNRC Region 3GE-4At 1115 EST, on 1/22/18, Fermi 2 determined that the site was in violation of its National Pollutant Discharge Elimination System (NPDES) permit due to an oil sheen being observed in a overflow canal that had breached the installed oil booms and entered navigable waterways. Approximately 5-10 gallons of oil has reached navigable water, which resulted in exceeding State limits. The oil is currently contained with no additional leakage to navigable waters and cleanup is in progress. The cause of the oil entering the overflow canal is under investigation. Reports will be made to the Michigan Department of Environmental Quality (MDEQ) and other local agencies. Since these reports are in the process of being made, this is considered a News Release or Notification to Other Government Agencies, therefore this event is reportable under 10 CFR 50.72(b)(2)(xi). The NRC Resident Inspector has been notified. The Licensee has notified the National Response Center.
ENS 5316716 January 2018 10:06:00Duane ArnoldNRC Region 3GE-4This 60-day telephone notification is being made under reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) to describe an invalid actuation of a containment isolation signal affecting more than one system. At 2230 CST on November 30, 2017, with the Duane Arnold Energy Center (DAEC) operating at 100 percent power, an invalid Group 3 isolation on the 'B' side of the Primary Containment Isolation System (PCIS) occurred. Group 3 isolation signals were generated for Primary Containment Isolation Valves for Drywell and Torus Ventilation and Purge, Containment Nitrogen Compressor Suction and Discharge, Recirculation Pump Seals, and Post Accident Sample System. This event was caused by a fault on the 1D25 Instrument AC Inverter. The fault was caused by an insufficient design clearance to ground and was corrected by increasing the clearance. All equipment responded in accordance with the plant design. Specifically, all actuations were complete and successful. There were no safety consequences or impacts on the health and safety of the public. The event was entered into DAEC's corrective action program for resolution. The NRC Resident Inspector has been notified.
ENS 5316511 January 2018 16:06:00FermiNRC Region 3GE-4On January 11, 2018, at 1041 EST, a planned train swap of the Reactor Building Heating Ventilation and Air Conditioning (RBHVAC) system resulted in the Technical Specification (TS) for secondary containment pressure boundary not being met for less than one minute. The maximum secondary containment pressure observed during that time was approximately 0.117 inches of vacuum water gauge. Secondary containment pressure was returned to within the TS operability limit of greater than or equal to 0.125 inches of vacuum water gauge per TS Surveillance Requirement (SR) 3.6.4.1.1 by starting Division 1 of the Standby Gas Treatment System (SGTS) in addition to the RBHVAC system already in operation. Secondary containment pressure is currently stable. Secondary containment was declared Operable at 1045 EST. There were no radiological releases associated with this event. Declaring secondary containment inoperable as a result of not meeting TS SR 3.6.4.1.1 is reportable under 10CFR 50.72(b)(3)(v)(C) as an event or condition that could have prevented the fulfillment of a safety function needed to control the release of radioactive material. The licensee has notified the NRC Resident Inspector.
ENS 5316210 January 2018 13:53:00Browns FerryNRC Region 2GE-4At 0928 CST on January 10, 2018, the Unit 3 reactor automatically scrammed due to a Reactor Protection System (RPS) signal generated from Turbine Control Valve Emergency Trip System pressure low. The reactor had been operating near 73 percent power for an emergent issue for Turbine Control Valve (TCV) No. 3. With TCV No. 3 out of service and closed, the unit was operating with RPS in a half scram condition. A subsequent failure of the TCV No. 2 sensing line resulted in RPS coincidence logic being met for TCV fast closure SCRAM. The investigation of the TCV No. 2 sensing line failure continues. All control rods fully inserted into the core. Main Steam Isolation Valves remained open with Main Turbine Bypass Valves controlling reactor pressure. Reactor Feedwater pumps remained in service to control reactor water level. Primary Containment Isolation Signals Groups 2, 3, 6, and 8 containment isolation and initiation signals were received. Upon receipt of these signals all required components actuated as required. Neither High Pressure Coolant Injection nor Reactor Core Isolation Cooling initiation signals were received. This event is reportable within 4 hours per 10 CFR 50.72(b)(2)(iv)(B) 'any event or condition that results in actuation of the Reactor Protection System (RPS) when the reactor is critical except when the actuation results from and is part of a preplanned sequence during testing or reactor operation.' It is also reportable within 8 hours per 10 CFR 50.72(b)(3)(iv)(A) and requires an LER within 60 days per 10 CFR 50.73(a)(2)(iv)(A). The NRC Resident inspector has been notified.