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 Entered dateSiteRegionReactor typeEvent description
ENS 5051725 February 2020 09:51:00ByronNRC Region 3Westinghouse PWR 4-LoopIn accordance with 10 CFR 50.72(b)(3)(ii)(A), this notification reports a degraded condition on Byron Station Unit 2 that occurred on October 7, 2014, when it was determined that the results of planned ultrasonic testing (UT) examinations performed on one CRDM penetration of the reactor vessel head would not meet the applicable acceptance criteria. Byron Station Unit 2 is presently in day eight of a refueling outage. The examinations were being performed to meet the requirements of 10 CFR 50.55a(g)(6)(ii)(D) and ASME Code Case N-729-1 to ensure the structural integrity of the reactor vessel head pressure boundary. The UT examinations continue for the remaining CRDM head penetrations. The repairs are currently being planned and will be completed prior to unit start-up. The NRC Resident Inspector has been notified of this condition.
ENS 5046825 February 2020 09:32:00Wolf CreekNRC Region 4Westinghouse PWR 4-LoopDuring a review of INPO Event Report 14-33, Direct Current Circuits Challenge Appendix R Fire Analysis, it was determined that portions of the control circuits for the Turbine Generator DC Emergency Lube Oil Pump and the Emergency DC Seal Oil Pump are not properly fused to prevent overload and possible secondary fires. The review found that a fire at the motor starter cabinet in the turbine building could cause specific smart hot shorts that could cause overheating of the control cable and result in secondary fires outside the turbine building. Based on this information, it was determined that this condition is unanalyzed and is potentially reportable per 10 CFR 50.72(b)(3)(ii)(B). Hourly fire watch compensatory measures are in place in the affected areas of the Turbine Building. The presence of compensatory measures in addition to automatic fire detection and suppression in these fire areas ensures protection of the equipment. The licensee has notified the NRC Resident Inspector.
ENS 5071625 February 2020 09:04:00South TexasNRC Region 4Westinghouse PWR 4-LoopAt approximately 1545 CST on 1/5/15, an employee was found unconscious by fellow teammates. His teammates, who are certified in cardiopulmonary resuscitation (CPR), commenced resuscitation until Matagorda County EMS arrived on the scene and transported the individual to Matagorda County Regional Hospital for medical treatment. The individual was evaluated by the Emergency Room Physician and was later pronounced deceased due to Cardiopulmonary Arrest. STP is investigating the incident. STP has reported this to the Occupational Safety and Health Administration (OSHA) and as such is reporting this in accordance with 10 CFR 50.72 (b)(2)(xi). A press release is not planned at this time. The NRC Resident Inspector was notified.
ENS 4959925 February 2020 08:52:00ByronNRC Region 3Westinghouse PWR 4-Loop

On December 2, 2013, activities are scheduled that will render the Technical Support Center (TSC) non-functional by removing the normal and emergency ventilation system from service. These activities are being performed in support of planned preventive maintenance. In preparation for these normal and emergency ventilation system outages, the TSC emergency responders were notified that if an emergency occurred during this outage the Emergency Coordinator and the TSC staff involved with classification, notification and PARS should report to the Work Execution Center. All other TSC personnel should report to the Operational Support Center. The duration of this TSC outage is expected to be less than 36 hours. The NRC Operations Center will be provided an update to this notification when the TSC normal and emergency ventilation is restored. This 8 hour notification in accordance with 10 CFR 50.72(b)(3)(xiii). The licensee notified the NRC Resident Inspector.

  • * * UPDATE ON 12/4/13 AT 0440 FROM BRIAN LEWIN TO DONG PARK * * *

The TSC is fully functional. The licensee will notify the NRC Resident Inspector. Notified R3DO (Riemer).

ENS 5078725 February 2020 08:52:00ZionNRC Region 3Westinghouse PWR 4-Loop

On 2/3/2015 at 1901 (CST), equipment important to safety failed to function as designed: 33 NAC MAGNASTOR systems containing Spent Nuclear Fuel, and 1 NAC MAGNASTOR system containing GTCC (Greater than Class C) waste, had air inlet vent partial blockage, totaling 50 percent or greater, due to environmental conditions, i.e., snow. (Please Note, no VCC systems reached full blockage.) NO personnel radiation exposure. Actions Taken lAW the NAC FSAR, Rev. 5, which included actions to immediately return the systems to less than 50 percent blockage and ongoing maintenance activities to return all systems to full operability. Additional information: 1. On 2/4/2015 at 0445 hrs. All 34 failed systems were restored to less than 50 percent blockage. 2. lAW the NAC FSAR we have 30 days from time of discovery to return each system to full operability. 3. A report will be followed up within 60 days per 10 CFR 72.75.g The licensee will notify the NRC Inspector and the State of Illinois.

  • * * RETRACTION FROM MARK BITTMAN TO JEFF HERRERA ON 2/9/15 AT 1736 EST * * *

This phone notification is being made to retract an earlier '24 Hour Report' made on February 4, 2015 at 1815 CST, NRC event #50787. On February 4, 2015 at 1810 CST, Zion Station notified NRC that on February 3, 2015 at 1901 CST, Equipment Important To Safety failed to function as designed that being 33 NAC MAGNASTOR systems containing Spent Nuclear Fuel and 1 NAC MAGNASTOR containing GTCC waste had their Inlet vents partially blocked, totaling 50% or greater, due to environmental conditions, i.e. Snow. This appeared to meet criteria of Non-Emergency notification under 10 CFR 72.75d(1)(i). NAC International has provided documentation stating we have 58 hours to perform the immediate action to unblock the VCC vents to greater than 50% and 30 days to completely unblock all the vents. This documentation is attached to this notification. Upon further review by Exelon Management, Zion Solutions Management and NAC, using criteria established in Sections 4.3.7.1 and 12.2.2 of the SER for CoC 72-1031, Amendment 0, no limits were exceeded. Actions were immediately initiated to restore the 34 failed systems to less than 50% blockage and were completed in less than 10 Hours. This is well within the 58 hour SAR basis. This is the basis for retracting the notification. Based on the above, (the licensee) management concludes this event does not meet the 24-hour reporting criteria established in 10 CFR 72.75d(1)(i). The R3DO(Pelke) was notified.

ENS 5023525 February 2020 08:52:00Diablo CanyonNRC Region 4Westinghouse PWR 4-LoopAt approximately 1535 Pacific Daylight Time (PDT) the Diablo Canyon Power Plant (DCPP) Emergency Planning Supervisor received a notification from an offsite DCPP employee that one of the emergency plan sirens had inadvertently actuated. The DCPP Shift Manager was notified of the situation by approximately 1545 PDT. The County of San Luis Obispo was notified of the inadvertent actuation of the single siren. At approximately 1550 PDT the County of San Luis Obispo sent out a county wide alert stating, 'Civil Emergency in this area until (1610) PDT prepare for action'. At approximately 1600 PDT the County of San Luis Obispo sent out another county wide alert stating, 'An early warning system siren was sounded in error. There is no emergency.' Field technicians have been sent out to the siren location and will shut the siren off. The cause of the inadvertent actuation of the siren is not known at this time. The licensee notified the NRC Resident Inspector and the County of San Luis Obispo.
ENS 4942225 February 2020 08:26:00CallawayNRC Region 4Westinghouse PWR 4-LoopA review of industry operating experience regarding the impact of unfused Direct Current (DC) ammeter circuits in the control room has determined that the condition described below to be applicable to Callaway Nuclear Plant resulting in an unanalyzed condition with respect to 10 CFR 50 Appendix R analysis requirements. The original plant wiring design and associated analysis for the Class 1E Train B batteries and chargers (including the B Swing charger) control room ampere indications do not include overcurrent protection features to limit the fault current. In the postulated event, a fire in the control room could cause one of the ammeter wires to hot short to the ground plane; simultaneously, the fire causes another DC wire from the opposite polarity on the same battery to also hot short to the ground plane. This would cause a ground loop through the unprotected ammeter wiring. This event could result in excessive current flow (heating) in the ammeter wiring to the point of causing a secondary fire in the raceway system. The secondary fire could adversely affect safe shutdown equipment and potentially cause the loss of the ability to conduct a safe shutdown as required by 10CFR50 Appendix R. This condition is being reported in accordance with 10 CFR 50.72(b)(3)(ii)(B) as an unanalyzed condition that significantly degrades plant safety. Compensatory measures (fire watches) have been implemented for affected areas of the plant. The NRC Resident Inspector has been notified. Similar Events: EN #49411 and EN #49419
ENS 4914325 February 2020 08:12:00Diablo CanyonNRC Region 4Westinghouse PWR 4-Loop

At 2120 PDT, Diablo Canyon Power Plant experienced a loss of the offsite 230 kV startup power source due to an offsite transmission system relay actuation, resulting in valid anticipatory starts of Units 1 and 2 three emergency diesel generators on each unit. All diesels successfully started but were not loaded. All systems operated as designed with no problems observed. The 230 kV startup power source is the only offsite power system designed to be immediately available following an accident. However, the safety related onsite emergency diesel system would have provided power to mitigate the consequences of an accident while the 230 kV was unavailable. Restoration of the 230 kV offsite power system is in progress." The licensee will notify the NRC Resident Inspector.

  • * * UPDATE FROM MICHAEL KENNEDY TO HOWIE CROUCH AT 1618 EDT ON 8/21/13 * * *

230 kV was restored to Operable on 06/24/13 at 0200 PDT. Normal 500 kV Offsite Power remained operable and was unaffected by this event. Following further review, Diablo Canyon Power Plant (DCPP) has determined that the loss of the 230 kV system was not a condition that could have prevented fulfillment of the safety function of a system credited to mitigate the consequences of an accident. This power source is not considered to be a safety-related system that is credited to mitigate any accident as described in the DCPP UFSAR, Chapters 6 and 15 accident analyses. PG&E concludes that the emergency diesel generators are the only power source needed to fulfill the accident mitigation function, and they did not become inoperable as a result of this event. The licensee will be notifying the NRC Resident Inspector. Notified R4DO (Werner).

ENS 4818525 February 2020 07:44:00McGuireNRC Region 2Westinghouse PWR 4-LoopDuke Energy notified the NC Wildlife Resource Commission of dead catfish in the vicinity of the McGuire low level intake. Notification was made on 8/13/12 at 1630 EDT. In addition, the NC Dept. of Environment and Natural Resources will be notified. The dead fish are suspected to have been caused by increasing lake temperature and decreased oxygen levels, which is common during the late summer. The NRC Resident Inspector will be notified.
ENS 4812625 February 2020 07:44:00CatawbaNRC Region 2Westinghouse PWR 4-LoopOn July 23, 2012, at 0508 EDT, the Technical Support Center (TSC) ventilation was tagged out for routine maintenance. It was believed that only the cooling function was affected and that the TSC ventilation system was still capable of performing its intended function of pressurization and filtration. A review by operations today determined that the TSC filtration and pressurization portion was also affected. Under certain accident conditions, the TSC may become unavailable due to the inability of the filtration system to maintain a habitable atmosphere. Compensatory measures exists to relocate the TSC to an alternate location. Currently it is expected that the TSC ventilation system maintenance will be completed by the end of the day shift today and turned over to operations. Operations should start up the system early during night shift (7/24). This is reportable to the NRC per 10 CFR 50.72 (b)(3)(xiii) as an eight hour non-emergency notification. The event had no effect on plant operations and no impact on public health and safety has been identified. The licensee will notify the NRC Resident Inspector, States and Counties.
ENS 4791725 February 2020 07:36:00SeabrookNRC Region 1Westinghouse PWR 4-LoopAt approximately 0515 EDT today, Seabrook experienced a brief loss of the Emergency Notification System (ENS). The ENS was inoperable for approximately four minutes due to an unknown cause. During this time, commercial telephone lines were available as a means of communication with the NRC. A subsequent communications check using the ENS phone was satisfactory. This event is being reported as an eight-hour notification in accordance with 10CFR50.72(b)(3)(xiii) for a loss of offsite ENS communications capability. Investigation into the cause continues and will be documented via the corrective action process. The licensee has notified the NRC Resident Inspector.
ENS 5342827 May 2018 00:40:00MillstoneNRC Region 1CE
Westinghouse PWR 4-Loop
County and state governments were notified due to the spurious actuation of a single emergency notification siren located in New London County in the Town of Lyme. The siren was silenced. If required, alternate notification of the public in the area will be through local Emergency Operations Center route alerting. The NRC Resident Inspector has been notified.
ENS 5342323 May 2018 16:10:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

At time 0848 (CDT), Main Steamline Radiation Monitor 2-RE-2328 (Main Steamline 2-04) lost communications and was declared non-functional.

With this radiation monitor non-functional, all of the emergency action levels for a steam generator tube rupture in steam generator 2-04 could neither be evaluated nor monitored. This unplanned condition is reportable as a loss of assessment capability per 10CFR50.72(b)(3)(xiii). Comanche Peak Nuclear Power Plant (CPNPP) has assurance of steam generator integrity and fuel cladding integrity and there is a negligible safety significance to the current condition from a public health and safety perspective. Additionally, compensatory measures are in place to assure adequate monitoring capability is available to implement the CPNPP emergency plan in the unlikely event of challenges to the steam generator or fuel cladding. The N16 radiation monitor serves as a backup with alarm function and Radiation Protection technicians have been briefed on taking local readings with a Geiger-Mueller tube on MSL 2-04. Corrective actions are being pursued to restore 2-RE-2328 to a functional status. The NRC Resident Inspector has been notified.

ENS 533867 May 2018 05:23:00SalemNRC Region 1Westinghouse PWR 4-LoopThis 4 and 8 hour notification is being made to report that Salem Unit 2 initiated a manual reactor trip and subsequent automatic Auxiliary Feedwater system actuation. The trip was initiated due to a 21 Reactor Coolant Pump reaching its procedural limit for motor winding temperature of 302F. Salem Unit 2 is currently stable in Mode 3. Reactor Coolant system pressure is 2235 PSIG and Reactor Coolant System temperature is 547 F with decay heat removal via the Main Steam Dump and Auxiliary Feedwater Systems. Unit 2 has no active shutdown technical specification action statements in effect. All control rods inserted on the reactor trip. All ECCS (emergency core cooling systems) and ESF (emergency safety function) systems functioned as expected. No safety related equipment or major secondary equipment was tagged for maintenance prior to this event. No personnel were injured during this event. The NRC Resident Inspector was notified. The Lower Alloways Creek Township will be notified.
ENS 533803 May 2018 18:40:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopDuring planned maintenance on Unit 2 Radiation Monitor 2-RE-4270 (Service Water Train B to Discharge Canal Rad Monitor), at 1220 CDT, several other Unit 2 Radiation Monitors that are used for Emergency Action Level evaluation became nonfunctional for about 1 hour. With these radiation monitors non-functional, all of the Emergency Action Levels associated with these monitors could neither be evaluated nor monitored. This unplanned condition is reportable as a loss of assessment capability per 10 CFR 50.72(b)(3)(xiii). A PC11 computer reboot restored the affected radiation monitors to a functional status. The NRC Resident Inspector has been notified.
ENS 5336124 April 2018 14:44:00Diablo CanyonNRC Region 4Westinghouse PWR 4-Loop

At 0357 (PDT), Unit 2 Containment High Range Radiation Monitor RM-31 was declared inoperable due to erratic indication. At this time, Containment High Range Radiation Monitor RM-30 was out of service for routine calibration. With both containment high range radiation monitors inoperable, this impacted DCPP's (Diablo Canyon Power Plant's) ability to evaluate containment radiation data for an unmonitored release in the event of an emergency. Compensatory measures were promptly put in place with the use of a portable radiation monitor as required by emergency preparedness procedures. This condition is being reported as a loss of assessment capability in accordance with 10 CFR 50.72(b)(3)(xiii). Actions are in progress to restore RM-30 and RM-31 to operable status. The NRC Senior Resident Inspector has been notified.

  • * * UPDATE ON 4/24/18 AT 1716 EDT FROM ERIC THOMAS TO DONG PARK * * *

RM-30 was restored to service. Portable radiation monitoring is not required. The licensee will notify the NRC Resident Inspector. Notified R4DO (Vasquez).

ENS 5335622 April 2018 04:28:00Watts BarNRC Region 2Westinghouse PWR 4-Loop

On April 22, 2018 at 0222 EDT, Watts Bar Nuclear Plant (WBN) Unit 2 entered TS (Technical Specifications) LCO (Limiting Condition for Operation) 3.0.3 due to both trains of the Residual Heat Removal System (RHRS) becoming inoperable. During surveillance testing, the gas void values on Emergency Core Cooling System (ECCS) piping common to both trains did not meet acceptance criteria. This caused both RHRS trains to become inoperable. Operations subsequently vented the RHRS to meet the acceptance criteria and exited TS LCO 3.0.3 at 0227 EDT. More frequent surveillances will be conducted to monitor gas void volumes while additional analysis is being performed to determine corrective actions. The NRC Resident Inspector has been notified.

  • * * RETRACTION FROM TONY PATE TO HOWIE CROUCH ON 5/4/18 AT 1455 EDT * * *

This event is being retracted. The initial report was based on a conservative acceptance criteria for gas accumulation adopted on April 19, 2018 when it was determined that the previously used acceptance criteria for gas accumulation in the ECCS was non-conservative. Additional analysis has subsequently been performed and determined that a higher gas accumulation acceptance criteria does not challenge operability. With a void of less than the acceptance criteria, in the event of ECCS actuation, the system piping support loads will remain within structural limits and the piping system will remain operable. Therefore, both trains of Unit 2 RHRS were operable and the previously reported 10 CFR 50.72(b)(3)(v)(B) event is being retracted. The NRC Resident Inspector staff has been informed of this event retraction. Notified R2DO (Desai) of this retraction.

ENS 5335522 April 2018 02:34:00Watts BarNRC Region 2Westinghouse PWR 4-Loop

On April 21, 2018 at 2152 EDT, Watts Bar Nuclear Plant (WBN) Unit 1 entered TS (Technical Specifications) LCO (Limiting Condition for Operation) 3.0.3 due to both trains of the Residual Heat Removal System (RHRS) becoming inoperable. During surveillance testing, the gas void values on Emergency Core Cooling System (ECCS) piping common to both trains did not meet acceptance criteria. This caused both RHRS trains to become inoperable. Operations subsequently vented the RHRS to meet the acceptance criteria and exited TS LCO 3.0.3 at 2222 EDT. More frequent surveillances will be conducted to monitor gas void volumes while additional analysis is being performed to determine corrective actions. The NRC Resident Inspector has been notified.

  • * * RETRACTION FROM ANTHONY PATE TO DONALD NORWOOD AT 1310 EDT ON 5/9/2018 * * *

This event is being retracted. The initial report was based on a conservative acceptance criteria for gas accumulation adopted on April 19, 2018 when it was determined that the previously used acceptance criteria for gas accumulation in the ECCS was non-conservative. Additional analysis has subsequently been performed and determined that a higher gas accumulation acceptance criteria does not challenge operability. With a void of less than the acceptance criteria, in the event of ECCS actuation, the system piping support loads will remain within structural limits and the piping system will remain operable. Therefore, both trains of Unit 1 RHRS were operable and the previously reported 10 CFR 50.72(b)(3)(v)(B) event is being retracted. The NRC Resident Inspector has been informed of this event retraction. Notified R2DO (Ehrhardt).

ENS 5335420 April 2018 22:22:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopOn Friday, April 20, 2018 at 1730 CDT, during the Braidwood Station Unit 1 refueling outage (A1R20), a scheduled ultrasonic test (UT) was performed on the top head to upper center disc weld of the Unit 1 reactor head. The UT identified 19 indications, 9 of which are not acceptable per ASME Section XI, 2001 Edition, 2003 Addenda, Paragraph IWB-3510. This event is reportable under 10 CFR 50.72(b)(3)(ii)(A) for 'Any event or condition that results in the condition of the nuclear power plant, including its principal safety barriers, being seriously degraded'. The licensee notified the NRC Resident Inspector.
ENS 5335320 April 2018 17:57:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopOn Friday, April 20, 2018 at 1042 CDT, Braidwood Station Unit 1 was at 0 percent power in Mode 6. The 1A Diesel Generator (DG) was inoperable with troubleshooting in progress. The 1B DG was being run for a normal monthly run in accordance with 1 BwOSR 3.8.1.2-2, 'Unit One 1B Diesel Generator Operability Surveillance,' and subsequently tripped. The trip was due to a failure of the overspeed butterfly valve actuator and springs, and not an actual overspeed condition. The unit entered Technical Specification (TS) 3.8.2, 'AC Sources - Shutdown,' Condition B for required DG inoperable. All required TS actions were met at the time of the 1B DG inoperability. The offsite power source remains available. At no time was residual heat removal lost. This event is reportable under 10 CFR 50.72(b)(3)(v)(B) for 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 remove residual heat. The licensee has notified the NRC Resident Inspector.
ENS 5334920 April 2018 00:55:00Watts BarNRC Region 2Westinghouse PWR 4-LoopOn April 19, 2018 at 1944 EDT, Watts Bar Nuclear Plant (WBN) determined that a preliminary analysis shows current acceptance criteria for gas accumulation in the WBN Unit 1 and Unit 2 Safety Injection System (SIS) and Residual Heat Removal System (RHRS) discharge piping may be non-conservative. The surveillances that check void values and allow venting of the systems are to be performed utilizing conservative criteria at more frequent intervals to ensure gas void volumes remain under acceptable limits. Additional analysis is being performed to determine final actions. The NRC Resident Inspector has been notified.
ENS 5334719 April 2018 20:00:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopOn Thursday, April 19, 2018 at 1152 CDT, a valid actuation of Engineered Safety Feature (ESF) Bus 141 Undervoltage (UV) Relay occurred. At the time, Braidwood Station Unit 1 was performing a pre-planned Bus 141 Undervoltage Actuation Surveillance, initiating the 1A Emergency Diesel Generator (EDG) to emergency start and sequence loads on the UV signal. Following the 1A EDG solely supplying electrical power to Bus 141, the EDG lost voltage resulting in an unplanned UV actuation of the ESF Bus 141. Subsequently, operators restored power to ESF Bus 141 via crosstie of the Unit 2 offsite power source. Shutdown cooling was maintained throughout the event as the 1B Residual Heat Removal train was unaffected by the actuation. This event is reportable under 10 CFR 50.72(b)(3)(iv)(A) for 'Any event or condition that results in valid actuation of any of the systems listed...', specifically 10 CFR 50.72(b)(3)(iv)(B)(8) for the 'Emergency ac electrical power systems, including: emergency diesel generators (EDGs)...'. The licensee notified the NRC Resident Inspector.
ENS 5334218 April 2018 09:29:00CookNRC Region 3Westinghouse PWR 4-LoopOn 4/18/2018, at approximately 0300 EDT, a contract cleaning employee notified her supervisor that she had found an oven mitt and a bottle containing a liquid that was possibly urine. The bottle had a temperature strip and heating element attached to it. These items were found in the trash in a bathroom in the training center located near the bathroom used for Fitness-for-Duty testing. The supervisor notified Security. Security responded and took possession of the objects. The licensee notified the NRC Resident Inspector.
ENS 5333413 April 2018 20:01:00CookNRC Region 3Westinghouse PWR 4-LoopAt 1555 EDT, the Unit 2 'CD' Emergency Diesel Generator (EDG) automatically started and loaded to 4kV Safeguards bus T21C. Testing was in-progress and the start was unplanned. Unit 2 is currently defueled. Unit 1 remains stable at 100 percent power. The South Spent Fuel Pit Cooling Train lost power due to a load shed. The South Spent Fuel Pit Cooling Pump was restarted on 2 'CD' EDG at 1614 EDT. The North Spent Fuel Pit Cooling Train remained in-service the entire time. There was no observable change in Spent Fuel Pool temperature. This event is reportable under 10 CFR 50.72(b)(3)(iv)(A), specified system actuation of an emergency diesel generator, as an eight (8) hour report. The NRC Resident Inspector has been notified.
ENS 5332812 April 2018 17:36:00MillstoneNRC Region 1Westinghouse PWR 4-LoopAt 1148 EDT on April 12, 2018, a 16.2 ounce bottle of Kombucha tea was found in a small refrigerator in the Administration Building inside the Protected Area. The bottle was found to have a small amount missing from the contents. Kombucha tea is a fermented tea containing trace amounts of alcohol, and is legally sold without restrictions. Dominion Energy Nuclear Connecticut had previously notified its workforce that Kombucha tea was prohibited from being consumed or carried onsite. The owner has not yet been determined. This is considered an alcoholic beverage and is being reported pursuant to the requirements of 10 CFR 26.719 as a 24 hour report. The NRC Resident Inspector, the State of Connecticut, and local authorities have been notified.
ENS 5332712 April 2018 12:14:00Watts BarNRC Region 2Westinghouse PWR 4-LoopAt 0920 EDT on April 12, 2018, the Watts Bar Unit 2 reactor automatically tripped while operating at 100 percent power. All control and shutdown bank rods inserted properly in response to the automatic reactor trip. All safety systems including Auxiliary Feedwater actuated as designed. The plant is stable with decay heat removal through Auxiliary Feedwater and Steam Dump Systems. The cause of the automatic reactor trip is being investigated. The automatic actuation of the Reactor Protection System (RPS) is being reported as a four-hour report under 10 CFR 50.72 (b)(2)(iv)(B). The expected actuation of the Auxiliary Feedwater System (an engineered safety feature) is being reported as an eight-hour report under 10 CFR 50.72 (b)(3)(iv)(A). The NRC Senior Resident Inspector has been notified for this event. The plant is currently stable at normal operating temperature and pressure. The grid is stable and the plant is in its normal shutdown electrical lineup. Unit 1 was unaffected by the Unit 2 trip.
ENS 533072 April 2018 11:20:00McGuireNRC Region 2Westinghouse PWR 4-LoopThis is an eight-hour, non-emergency notification for a loss of emergency assessment capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the work activity affects the functionality of an emergency response facility. A planned modification to the Technical Support Center (TSC) ventilation system started on April 2, 2018. The work activity includes replacement of the air conditioning system. The work duration is approximately three weeks. If an emergency is declared requiring TSC activation during this period, the TSC will be staffed and activated using existing emergency planning procedures unless the TSC becomes uninhabitable due to ambient temperature, radiological, or other conditions. If relocation of the TSC becomes necessary, the Emergency Coordinator will relocate the TSC staff to an alternate location in accordance with applicable site procedures. The Emergency Response Organization team has been notified of the TSC modifications and the possible need to relocate during an emergency. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5330531 March 2018 19:33:00Indian PointNRC Region 1Westinghouse PWR 4-LoopOn March 31, 2018, during the Indian Point Unit 2 refueling outage, with the reactor defueled and the head removed and located on the head stand, and all fuel from the reactor vessel removed and located in the spent fuel pool, while performing planned examinations on the 97 reactor vessel head penetrations, it was determined that one penetration could not be dispositioned as acceptable per the requirements of 10CFR50.55a for the reactor coolant system pressure boundary. The examinations are being performed to the meet the requirements of 10CFR50.55a(g)(6)(ii)(D), and ASME Code Case N-729-4, to find potential flaws/indications well before they increase to a degree that could potentially challenge the reactor vessel head pressure boundary. All other reactor vessel head penetrations have had a bare metal visual inspection completed with no other indications identified. The station is currently performing the remaining non-destructive examinations required by Code Case N-729-4. Repairs are currently being planned, and will be completed prior to entering Mode 5 from the current refueling outage. This is reportable, pursuant to 10CFR50.72(b)(3)(ii)(A) since the as found indications did not meet the applicable acceptance criteria referenced in ASME Code Case N-729-4 to remain in-service without repair. The NRC Resident Inspector has been informed. The licensee has also notified the NY Public Service Commission.
ENS 5329126 March 2018 20:07:00Watts BarNRC Region 2Westinghouse PWR 4-LoopAt 1839 Eastern Daylight Time (EDT) on March 26, 2018, a Main Control Room (MCR) alarm was received for low control room positive pressure. At 1840 EDT, a Control Room Envelope (CRE) door was found ajar and immediately closed. Technical Specification 3.7.10, Control Room Emergency Ventilation System (CREVS), was declared not met for both trains and Condition B entered. At 1840 EDT on March 26, 2018, the alarm cleared, CREVS was declared operable and LCO (Limiting Condition for Operation) 3.7.10, Condition B was exited. The safety function of the CRE boundary is to ensure the in-leakage of unfiltered air into the CRE will not exceed the in-leakage assumed in the licensing basis analysis of Design Basis Accident (DBA) consequences to CRE occupants. From 1839 EDT to 1840 EDT, WBN (Watts Bar Nuclear) was unable to validate that CREVS could fulfill its required Safety Function. This event is being reported pursuant to 10 CFR 50.72(b)(3)(v)(D). A watch has been posted at the door to prevent recurrence. The NRC Resident Inspector has been notified.
ENS 5327119 March 2018 10:49:00CatawbaNRC Region 2Westinghouse PWR 4-LoopAutomatic actuation of the 2B CA (Auxiliary Feedwater) System. At 0329 (EDT on) 03-19-18, with Unit 2 in Mode 5, an actuation of the 2B CA (Auxiliary Feedwater) system occurred during maintenance associated with the 2B Main Feedwater Pump. The cause of the CA (Auxiliary Feedwater) system automatic start was an unanticipated reset and subsequent trip signal of the 2B Main Feedwater pump during maintenance activities. The 2B CA Pump/Train automatically started as designed when the 'Loss of Both Main Feedwater Pumps' signal was received. The system operated as required. This event is being reported in accordance with 10CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the CA System. There was no impact on the health and safety of the public or plant personnel. The NRC Resident has been notified.
ENS 5323027 February 2018 01:15:00CookNRC Region 3Westinghouse PWR 4-LoopAt 2247 Eastern (Standard) Time the Unit 1 Control Room was notified of a personnel injury in the Unit 1 lower containment. Unit 1 is currently in Mode 1 at 100 (percent) (Reactor) Power and the individual was working in lower containment. The individual's injury appears to be Heat Exhaustion. Site emergency medical technicians responded to the scene and the individual was transported to a local medical facility via ambulance. At the time of transport, the individual was considered to be potentially contaminated because complete surveys could not be performed while the individual was immobilized for transfer. The individual and clothing were surveyed at the hospital by a resident Radiation Protection Technician and no contamination was found. This report is being made pursuant to 10 CFR 50.72(b)(3)(xii), 'Any event requiring the transport of a radioactively contaminated person to an offsite medical facility for treatment.' The NRC Resident Inspector has been notified.
ENS 5322925 February 2018 11:24:00MillstoneNRC Region 1Westinghouse PWR 4-LoopA non-licensed employee was found in violation of the sites Fitness for Duty Policy. The employee's access authorization to the plant has been terminated. The NRC Resident Inspector has been notified.
ENS 5321716 February 2018 13:58:00McGuireNRC Region 2Westinghouse PWR 4-LoopAt 1014 (EST) hours on 2/16/18, with Unit 1 in Mode 1 at approximately 100 percent power, the reactor automatically tripped when the Reactor Trip Breakers opened during Train B Solid State Protection System (SSPS) testing. The trip was uncomplicated with all systems responding normally post-trip. Operations manually started the motor driven auxiliary feedwater pumps. The turbine driven auxiliary feedwater pump (TDCAP) auto-started on low steam generator level. A Feedwater Isolation occurred as designed due to the Reactor Trip and Lo Tave condition. Operations stabilized the plant. Decay heat is being removed by the condenser. Unit 2 is not affected. Due to the Reactor Protection System actuation while critical, actuation of the TDCAP and motor driven auxiliary feedwater pumps along with the Feedwater Isolation, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B) and an 8 hour non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5320312 February 2018 11:21:00CallawayNRC Region 4Westinghouse PWR 4-Loop

On February 12, 2018, during performance of a TSC Diesel Generator Functional Test, the TSC Ventilation could not be placed in Filter Mode. Filter Mode operation is credited in the TSC habitability analysis of record. The TSC was declared non-functional due to the unavailability of the filtration system. The Emergency Operations Facility (EOF) is available for use as a backup TSC. Additionally, the TSC would be available for emergency response purposes for events that do not involve a release in progress. The NRC Resident Inspector has been notified.

  • * * UPDATE AT 1605 EST ON 2/12/2018 FROM JEREMY MORTON TO MARK ABRAMOVITZ * * *

At 1258 CST, TSC ventilation was declared operable. A start permissive lever was adjusted to remedy interference. The licensee notified the NRC Resident Inspector.

ENS 531964 February 2018 12:00:00Watts BarNRC Region 2Westinghouse PWR 4-Loop

At 0445 (EST) on February 4, 2018, Watts Bar Unit 1 entered Technical Specification 3.6.1 condition A and 3.6.3 condition A.1 and A.2 due to inoperable containment penetration thermal relief check valves 1-CKV-31-3407 and 1-CKV-31-3421 associated with one train of the Containment Incore Instrument Room Chiller system. During surveillance testing, the thermal relief check valves failed to open and pass flow as required by acceptance criteria. The two penetrations were subsequently drained and isolated in accordance with the surveillance procedure to remove any thermal expansion concerns. Technical Specification 3.6.1 was exited February 4, 2018 at 0512 once the two penetrations were drained and isolated. The purpose of the thermal relief check valves is to allow flow from an isolated penetration back into the upstream containment piping to prevent over-pressurization due to thermal expansion. Over-pressurization of an isolated containment penetration could potentially cause the penetration or both of the isolation valves to fail and provide a direct flow path to the environment from the potentially contaminated containment atmosphere under certain Design Basis Accidents. Therefore, failure of the thermal relief check valves to open could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material. This event is being reported pursuant to 10 CFR 50.72(b)(3)(v)(C). NRC Resident Inspector has been notified.

  • * * RETRACTION AT 1336 EST ON 03/29/2018 FROM TONY PATE TO TOM KENDZIA * * *

The purpose of this notification is to retract ENS notification 53196 made on 2/4/2018 for Watts Bar Nuclear Plant. The previous notification reported a surveillance failure of two containment penetration thermal relief check valves that, at the time of discovery, could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material. After Engineering evaluation, it has been determined there is reasonable assurance the two thermal relief check valves (1-CKV-31-3407 and 1-CKV-31-3421) were capable of performing their specified safety function to isolate containment and act as a thermal relief device during a design basis accident. The basis of the evaluation included: 1. No maintenance activities or interactions with the check valves had occurred since last tested. 2. All surveillance testing for the valves was within required frequency. 3. The opening force for a new check valve of the same size and similar to 1-CKV-31-3407 and 1-CKV-31-3421 is 0.38 pounds. Engineering analysis has determined the minimum failure pressure of the piping systems associated with the containment penetration in question is 450 psig. If it is assumed the force applied on the check valve seat reaches 450 psig, the force applied on the seat would reach 111 pounds or 300 times the force required to open a new, clean check valve. Based on engineering judgement of previous operating experience where the pressure required to open the same stuck check valve was within a safety factor of 6 to potential equipment damage, the thermal relief check valves would have opened prior to equipment damage and thus the identified condition would not have resulted in adversely affecting the containment isolation boundary. Entry into Technical Specification (TS) 3.6.1 condition A on 2/4/2018 at 0445 has been retracted. Although not a loss of safety function, the containment penetrations associated with 1-CKV-31-3407 and 1-CKV-31-3421 remain inoperable and are being tracked by TS 3.6.3 condition A.1 and A.2. The NRC Resident Inspector has been notified. Notified the R2DO (Rose).

ENS 5318426 January 2018 01:37:00Diablo CanyonNRC Region 4Westinghouse PWR 4-LoopAt 1901 PST on January 25, 2018, the Control Room received a fire alarm, followed by screen wash and 480v load center alarms a few minutes later. The intake operator and on-site fire department personnel were promptly dispatched to the scene and confirmed within 15 minutes there was no active fire. As a conservative measure, off-site fire assistance was initially requested, however (this request) was canceled a short time later. While on-site fire personnel were locally assessing the damage to screen wash pump 1-2, a brief flare-up occurred at the pump motor which was immediately extinguished. Units 1 and 2 remained stable and two screen wash pumps remain available. There is no risk to plant safety or personnel and both units continue to operate at power. Current efforts are focused on determining the cause of the situation. The licensee notified the NRC Resident Inspector and CAL FIRE. The licensee issued a media/press release.
ENS 5318023 January 2018 05:02:00BraidwoodNRC Region 3Westinghouse PWR 4-Loop

At 0400 (CST) on 1/23/2018 the Braidwood Technical Support Center (TSC) HVAC (Heating, Ventilation and Air Conditioning) Emergency Makeup Air Filter train was taken out of service to perform a planned Makeup Air Filter charcoal replacement. The TSC HVAC Makeup Air Filter train will be rendered nonfunctional during the charcoal replacement. Subsequent charcoal and HEPA filter testing will restore functionality of the TSC HVAC Makeup Air Filter train. The expected duration of the charcoal replacement and subsequent testing is 30 hours. If an emergency is declared requiring TSC activation during the time TSC HVAC is non-functional, the TSC will be staffed and activated using existing emergency planning procedure unless the TSC becomes uninhabitable due to ambient temperature, radiological, or other conditions. If relocation of the TSC becomes necessary, the Emergency Director will relocate the TSC staff to an alternate location in accordance with applicable site procedures. This notification is being made in accordance with 10 CFR 50.72(b)(3)(xiii) due to a major loss of emergency preparedness capability. An update will be provided once the TSC HVAC Emergency Makeup Air Filter train functionality has been restored. The licensee has notified the NRC Resident Inspector.

  • * * UPDATE AT 1645 EST ON 01/26/2018 FROM PAUL ARTUSA TO JEFF HERRERA * * *

On 1/26/18 at time 1539 EST, the TSC HVAC Emergency Makeup Air Filter train was returned to service following the planned Makeup Alr Filter charcoal replacement. Functionality was verified by charcoal and HEPA filter post maintenance testing. The licensee has notified the NRC Resident Inspector. Notified the R3DO (Cameron).

ENS 5316010 January 2018 02:13:00McGuireNRC Region 2Westinghouse PWR 4-Loop

During normal power operations at 100 percent power on Unit 2, both trains of Containment Air Return Fans (CARF) were declared inoperable at 19:28 (EST) on January 9, 2018 due to a common issue with control power fuses. The fuses potentially could not handle the in-rush current upon re-energizing the circuits. This condition resulted in a loss of a reasonable expectation that the Unit 2 Containment Air Return Fans would meet their design safety function and mitigate an accident. This loss of safety function is reportable under 10CFR50.72(b)(3)(v)(D), 8 hour report. The site entered T.S. 3.0.3 at 19:28 and exited at 20:54 when repairs to 2B CARF were completed. 2A CARF repairs are complete. There was no impact on the health and safety of the public or plant personnel. The senior NRC Resident Inspector has been notified. The licensee verified this problem does not affect unit-1.

  • * * RETRACTION AT 0939 EST ON 03/08/2018 FROM JUSTIN BLACK TO TOM KENDZIA * * *

A subsequent evaluation determined that the fuses for the Containment Air Return Fans (CARFs) would be able to perform their safety function and were operable at the time of discovery. The limiting safety condition for the fuses is the return to power following a Loss of Offsite Power (LOOP). The evaluation determined that the fuses would satisfy their safety function upon re-energizing the circuits if a LOOP occurred and would not impact the ability of the CARFs to perform their safety function. The subject fuses were replaced on January 9, 2018." The Licensee notified the NRC Senior Resident Inspector. Notified the R2DO (Musser).

ENS 531432 January 2018 17:17:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 1137 CST on January 2, 2018, Comanche Peak Nuclear Power Plant (CPNPP) Unit 2 experienced an unplanned loss of the Plant Computer System (PCS). The loss of the Unit 2 PCS resulted in a loss of emergency assessment capability to the CPNPP Technical Support Center (TSC) and Emergency Operations Facility (EOF) for greater than 60 minutes. This report is being made pursuant to 10 CFR 50.72(b)(3)(xiii), any event that results in a loss of emergency assessment capability, off-site response capability, or off-site communications ability. The NRC Resident Inspector has been informed. Repairs are on-going.
ENS 531411 January 2018 12:45:00South TexasNRC Region 4Westinghouse PWR 4-LoopA South Texas Project Offsite Emergency Notification siren (#7) was inadvertently going off. The Matagorda County Sheriff's office notified the Emergency Response Organization at the station of the siren actuation. Station personnel are addressing the issue with the siren. The Matagorda County Sheriff's office was the only offsite agency that was contacted during this event. This notification is being made under 10CFR50.72(b)(2)(xi) as an event where other government agencies were notified. The licensee has personnel at the siren which is no longer alarming (1.5 hours after alarm notification). The licensee notified the NRC Resident Inspector
ENS 5313220 December 2017 18:18:00Watts BarNRC Region 2Westinghouse PWR 4-LoopOn December 20, 2017, at 1040 Eastern Standard Time (EST), the Watts Bar Nuclear Plant (WBN) 1B-B 6.9kV Shutdown Board (SDBD) normal feeder breaker opened. The loss of voltage to the 1B-B SDBD resulted in the start of the 1B-B Motor Driven Auxiliary Feedwater (MDAFW) pump, the Unit 1 Turbine Driven Auxiliary Feedwater (TDAFW) pump, and the start of all four Emergency Diesel Generators (EDGs). Power was restored to the 1B-B 6.9 kV SDBD when it loaded on to its associated EDG. Following initial investigation, the 1B-B 6.9 kV SDBD was transferred to its alternate offsite power source, Common Station Service Transformer (CSST) C at 1217 EST. At 1230 EST, the 1B-B 6.9 kV SDBD alternate feeder breaker opened. The loss of voltage to the 1B-B SDBD did not result in the restart of the 1B MDAFW pump, the Unit 1 TDAFW pump, or EDGs; this equipment remained running from the earlier event. Power was restored to the 1B-B 6.9 kV SDBD when it loaded on to its associated EDG. Restoration of normal offsite power to the 1B-B SDBD was completed at 1654. Other than several common Unit Technical Specifications having not been met, Unit 2 was not operationally impacted by the transfer of the 1B-B Shutdown Board to onsite power and remains in Mode 1 at 100% power. This report is made per 10 CFR 50.72(b)(3)(iv)(A). NRC Resident Inspector has been notified. The licensee investigation continues for the cause of the event.
ENS 5311914 December 2017 11:29:00CallawayNRC Region 4Westinghouse PWR 4-LoopOn December 13, 2017, Callaway determined that a violation of one provision of the site's Fitness For Duty (FFD) policy had occurred. FFD testing confirmed the use of a controlled substance. The violation was committed by a non-licensed, supervisory employee. The individual's unescorted access to the plant has been removed. The NRC Resident Inspector has been notified by the licensee.
ENS 5311812 December 2017 23:04:00South TexasNRC Region 4Westinghouse PWR 4-LoopAt 1757 CST on December 12, 2017, South Texas Project Electric Generating Station (STPEGS) Unit 1 and Unit 2 experienced an unplanned partial loss of the Integrated Computer System (ICS). The partial loss of Unit 1 and Unit 2 ICS resulted in a major loss of emergency assessment capability to STPEGS Unit 1 and Unit 2 Technical Support Center (TSC) for greater than 75 minutes. Assessment capability has been verified to be available in the Emergency Operations Facility (EOF). This report is being made pursuant to 10 CFR 50.72(b)(3)(xiii), any event that results in a major loss of emergency assessment capability, off site response capability, or off site communications ability. The NRC Resident Inspector has been informed.
ENS 531056 December 2017 01:55:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 2000 (CST), Comanche Peak experienced a failure of SCADA B of the PC11 Radiation Monitor System. This failure caused a loss of Unit 1 Main Steam Line 1-01 and 1-03 Radiation Monitors (1-RE-2325 and 1-RE-2327) and Train A and Train B Station Service Water Radiation Monitors (1-RE-4269 and 1-RE-4270). With the Main Steam Line Radiation Monitors nonfunctional, all of the emergency action levels for a steam generator tube rupture in steam generators 1-01 and 1-03 could neither be evaluated nor monitored. With the Station Service Water Radiation Monitors non-functional, all of the emergency action levels for a radioactive release through station service water could neither be evaluated nor monitored. This unplanned condition is reportable as a loss of assessment capability per 10 CFR 50.72(b)(3)(xiii). Comanche Peak Nuclear Power Plant (CPNPP) has assurance of steam generator integrity, reactor coolant system integrity, and fuel cladding integrity and there is a negligible safety significance to condition from a public health and safety perspective. Additionally, compensatory measures are in place to assure adequate monitoring capability is available to implement the CPNPP emergency plan in the unlikely event of challenges to the steam generator, reactor coolant system, or the fuel cladding. Until these radiation monitors were restored, Operations implemented compensatory measures to monitor the Condenser Off Gas Radiation Monitor for early signs of a steam generator tube leak/rupture and Radiation Technicians were briefed on taking local readings with a Geiger-Mueller tube on the Main Steam Lines. Chemistry Technicians were performing hourly samples of Station Service Water and reporting results to the Control Room. Corrective actions were pursued to restore the non-functional radiation monitors back to service. Those actions are complete and all radiation monitors have been restored to service. The NRC Resident Inspector has been notified. PC11 is a computer common to both Units. The failure happened during radiation monitor maintenance to a single monitor, which unexpectedly affected multiple monitors.
ENS 5309930 November 2017 17:17:00SalemNRC Region 1Westinghouse PWR 4-Loop

An Unusual Event was declared at 1657 EST due to an earthquake detected onsite. The Unusual Event was declared under EAL HU1.1. There is no release in progress due to this event. There are no protective actions recommended at this time. The Licensee will notify the NRC Resident Inspector. Note: See also EN #53101 for Hope Creek Unusual Event.

  • * * UPDATE FROM JOSHUA MYERS TO DONALD NORWOOD AT 1742 EST ON 11/30/2017 * * *

An earthquake was felt onsite at time 1645 EST. Multiple phone calls were made to the Control Room confirming the earthquake. It was verified there was an earthquake felt in Delaware with a magnitude of 4.4. Neither seismic monitor at Salem Unit 1, Salem Unit 2, and Hope Creek actuated. There is no indication of any damage to any systems or plant structures. Plant walk-downs have been initiated in accordance with plant operating procedures for a seismic event. No injuries have been reported to the Control Room. The licensee will notify the NRC Resident Inspector and State and local government agencies. Notified R1DO (Gray), DHS SWO, FEMA Operations Center, DHS NICC, FEMA NWC (email), and DHS Nuclear SSA (email).

  • * * UPDATE FROM THOMAS CLARK TO DAVID AIRD AT 2137 EST ON 11/30/2017 * * *

The licensee terminated the Unusual Event at 2125 EST on 11/30/2017 following plant walkdowns that revealed no damage to plant structures, systems, or components. The NRC Resident Inspector has been notified. Notified R1DO (Gray), IRD (Grant), and NRR EO (Miller), DHS SWO, FEMA Operations Center, DHS NICC, FEMA NWC (email), and DHS Nuclear SSA (email).

ENS 5309629 November 2017 18:09:00Diablo CanyonNRC Region 4Westinghouse PWR 4-LoopOn 11/29/2017, at approximately 1125 (Pacific Time), an employee reported finding a container of herbal tea (Kombucha) in a refrigerator in a warehouse building break room, which is located inside the Protected Area. Kombucha tea is a fermented tea containing trace amounts of alcohol. Based on the product labeling, which indicates the beverage may contain more than 0.5 percent alcohol by volume, and which also includes a government alcoholic beverage health warning label, this is being considered an alcoholic beverage, and is being reported under the requirements of 10 CFR Part 26.719. An investigation is under way to identify who may have brought the kombucha tea on-site. The NRC Senior Resident Inspector has been notified.
ENS 5309528 November 2017 10:01:00Wolf CreekNRC Region 4Westinghouse PWR 4-Loop

(On) Monday, 11/20/17, (the licensee) received a call from the MRO (Medical Review Officer) staff that the Opiate blind submitted on 11/14/17 did not test as expected. The confirmatory test was positive for codeine and morphine but negative for 6-acetylmorphine. (The licensee) requested a retest by the MRO to the laboratory. The MRO staff contacted the provider of the blind specimens for documentation of the blind analysis. The lab was requested on 11/21/17 to perform the retest by the MRO. (On) 11/27/17, the results from the lab on the retest were virtually the same as the original test result. The lab's Certifying Scientist provided a letter documenting their findings. The MRO staff informed us (Wolf Creek) and we requested copies of all documentation from the provider of the blinds, the lab and any notes from the MRO staff. Informed Superintendent Access Screening of the test results. (The licensee) contacted two plants to verify reportability under 10 CFR 26.719. (The licensee) initiated CR 00117707 to document the occurrence. Superintendent contacted licensing and management. The licensee will inform the NRC Resident Inspector and R4 NRC Security Inspector.

  • * * RETRACTION ON 12/6/17 AT 1559 EST FROM LARRY HAUTH TO DONG PARK * * *

This event was reported under 10 CFR 26.719(c)(3). Further review shows that this event should have been reported under 10 CFR 26.719(c)(1), which only required a Licensee Event Report, not an Event Notification. This notification is retracted. The licensee will notify the NRC Resident Inspector. Notified R4DO (Hipschman) and FFD Group via email.

ENS 5309226 November 2017 16:16:00Watts BarNRC Region 2Westinghouse PWR 4-LoopOn November 26, 2017, at 1225 Eastern Standard Time (EST), the Watts Bar Nuclear Plant (WBN) Unit 2 experienced an unplanned ECCS discharge to the Unit 2 Reactor Coolant System (RCS) while de-pressurized, in Mode 5, with the Pressurizer vented to the Pressurizer Relief Tank. ECCS injection via the Boron Injection flow path occurred during planned Safety Injection system Engineered Safety Features Actuation System (ESFAS) testing. The Boron Injection flow path should have been isolated and should not have resulted in any injection flow to the Unit 2 RCS. Since the injection was not a part of the pre-planned test this is reportable under 10 CFR 50.72(b)(2)(iv), System Actuation. All other systems responded as expected in accordance with the ESFAS testing procedure. The unintended ECCS injection flow was isolated and flow through the Boron Injection path was verified to be stopped at 1232 EST. The Unit 2 Pressurizer level and pressure remained below any limits and no safety limits were challenged. NRC Resident Inspector has been notified.
ENS 530618 November 2017 11:52:00McGuireNRC Region 2Westinghouse PWR 4-LoopAt 0824 EST on 11/8/17, a Switchyard Autotransformer began to burn due to an equipment failure. The autotransformer supports interconnectivity between each side of the switchyard and is not required for switchyard operation. There was no work in progress on the associated autotransformer at the time of the event. The autotransformer and the switchyard are outside the protected area approximately one mile away. The fire was contained to the autotransformer only. The fault has been electrically isolated and there was no effect on either MNS (McGuire Nuclear Site) Unit 1 or Unit 2 operations. No personnel were injured as a result of the fire. Local Fire Department responded and has contained the fire. MNS fire brigade leader along with switchyard maintenance have confirmed no effects to the MNS bus lines, power availability, or the ability for the site to generate power. Environmental personnel have made a notification to the National Response Center due to the oil and foam mixture occurring as a result of the fire response. McGuire hazmat personnel are currently working to contain this oil and foam mixture. Environmental personnel are also submitting a report to the NC (North Carolina) Department of Environmental Water Quality within 24 hours. There is no impact to the public. The NRC Resident Inspector has been informed.
ENS 5304430 October 2017 15:50:00Watts BarNRC Region 2Westinghouse PWR 4-LoopAt 0942 Eastern Daylight Time (EDT) on October 30, 2017, a Main Control Room (MCR) alarm was received for low control room positive pressure. At 0943 EDT, a Control Room Envelope (CRE) door was found ajar and immediately closed. Technical Specification 3.7.10 Control Room Emergency Ventilation System (CREVS) was declared not met for both trains and Condition B entered. At 0945 EDT the alarm cleared, CREVS was declared operable and LCO 3.7.10, Condition B was exited. The safety function of the CRE boundary is to ensure the in-leakage of unfiltered air into the CRE will not exceed the in-leakage assumed in the licensing basis analysis of Design Basis Accident (DBA) consequences to CRE occupants. From 0942 EDT to 0943 EDT WBN (Watts Bar Nuclear) was unable to validate that CREVS could fulfill its required Safety Function. This event is being reported pursuant to 10 CFR 50.72(b)(3)(v)(D). NRC Resident Inspector has been notified.