Semantic search

Jump to: navigation, search
Search

Edit query Show embed code

The query [[Category:ENS Notification]] [[Reactor type::Westinghouse PWR 4-Loop]] was answered by the SMWSQLStore3 in 0.1025 seconds.


Results 1 – 50    (Previous 50 | Next 50)   (20 | 50 | 100 | 250 | 500)   (JSON | CSV | RSS | RDF)
 Entered dateSiteRegionReactor typeEvent description
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 5342623 May 2018 18:32:00CallawayNRC Region 4Westinghouse PWR 4-LoopOn May 23, 2018 Callaway determined that a violation of one provision of the site's Fitness for Duty (FFD) policy occurred. FFD pre-access testing confirmed a test failure for alcohol. The violation was committed by a non-licensed supervisory employee. The individual did not hold unescorted access to the plant but did perform behavioral observation program (BOP) duties. The BOP qualification has been removed. The NRC Resident Inspector has been notified by the licensee.
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 5339811 May 2018 15:19:00Watts BarNRC Region 2Westinghouse PWR 4-LoopAt 1011 EDT on May 11, 2018, Containment Shield Building Annulus differential pressure exceeded the required limit. The Shield Building was declared inoperable requiring entry into Technical Specification (TS) 3.6.15 Conditions A and B. The event was initiated by failure of the operating annulus vacuum fan. Main Control Room Operators manually started the stand-by annulus vacuum fan to recover pressure. Shield Building Annulus differential pressure was restored to the required value at 1016 EDT and TS 3.6.15 Condition A and B were exited on May 11, 2018 at 1016 EDT. The failure mechanism for the annulus vacuum fan is being investigated. The Containment Shield Building ensures the release of radioactive material from the containment atmosphere is restricted to those leakage paths and associated leakage rates assumed in the accident analysis during a Loss of Coolant Accident (LOCA). The Emergency Gas Treatment System (EGTS) would have automatically started and performed its design function to maintain the Shield Building Annulus differential pressure within required limits. The event is being reported pursuant to 10 CFR 50.72(b)(3)(v)(C) and 10 CFR 50.72(b)(3)(v)(D). The NRC Resident has been notified.
ENS 533887 May 2018 16:31:00CallawayNRC Region 4Westinghouse PWR 4-LoopOn May 7, 2018, during an engineering review of mission time requirements for Technical Specification related equipment, a deficiency was discovered regarding the Emergency Operating Procedure (EOP) guidance for natural circulation cooldown with a stagnant loop. This condition could be the result of a postulated Main Steam Line Break with a loss of offsite power. During a natural circulation cooldown with a faulted steam generator, flow in the stagnant reactor coolant system (RCS) loop associated with the isolated faulted steam generator (SG) could stagnate and result in elevated temperatures in that loop. This becomes an issue when RCS depressurization to residual heat removal system (RHR) entry conditions is attempted. The liquid in the stagnant loop will flash to steam and prevent RCS depressurization. In this condition, the time required to complete the cooldown would be sufficiently long that the nitrogen accumulators associated with Callaway's atmospheric steam dumps and turbine driven auxiliary feedwater pump flow control valves would be exhausted. The atmospheric steam dumps and turbine driven auxiliary feedwater pump would not be capable of performing their specified safety functions of cooling the plant to entry conditions for RHR operation. This issue has been analyzed by Westinghouse in WCAP-16632-P. This WCAP determined that to prevent loop stagnation, the RCS cooldown rate in these conditions should be limited to a rate dependent on the temperature differential present in the active loops. The WCAP analysis was used to support a revision to the generic Emergency Response Guideline (ERG) for ES-0.2 "Natural Circulation Cooldown." Figure 1 in ES-0.2 provides a curve of the maximum allowable cooldown rate as a function of active loop temperature differential which is directly proportional to the level of core decay heat. At the time of discovery of this condition, Callaway's EOP structure did not ensure that the ES-0.2 guidance would be implemented for a natural circulation cooldown with a stagnant loop. Callaway has issued interim guidance to the on-shift personnel regarding this concern and is in the process of revising the applicable EOPs. This condition is reportable per 10 CFR 50.72(b)(3)(v) 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 (A) Shutdown the reactor and maintain it in a safe shutdown condition, (B) Remove residual heat, or (D) mitigate the consequences of an accident." The licensee notified the NRC Resident Inspector of this condition.
ENS 533877 May 2018 06:42:00CookNRC Region 3Westinghouse PWR 4-LoopOn May 7, 2018 at 0336 (EDT), DC Cook Unit 2 Reactor was manually tripped due to a high-high level experienced in the East Moisture Separator Drain Tank (MSDT) of the Moisture Separator Reheater (MSR). This notification is being made in accordance with 10 CFR 50.72(b)(2)(iv)(B), Reactor Protection System (RPS) actuation as a four (4) hour report, and under 10 CFR 50.72(b)(3)(iv)(A), specified system actuation of the Auxiliary Feedwater System, as an eight (8) hour report. The NRC Resident Inspector has been notified. Unit 2 is being supplied by offsite power. All control rods fully inserted. All Aux Feedwater Pumps started properly. Decay heat is being removed via the Steam Generator Power Operated Relief Valves following Main Steam Stop Valve closure at 0431 due to a slow RCS (Reactor Coolant System) cooldown. Preliminary evaluation indicates all plant systems functioned normally following the Reactor Trip. DC Cook Unit 2 remains stable in Mode 3 while conducting the Post Trip Review. No radioactive release is in progress as a result of this event.
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 5337130 April 2018 14:53:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopAt 1124 CDT, Braidwood Unit 1 experienced an automatic Reactor Trip. The cause of the Reactor Trip was a Turbine Trip with reactor power greater than P-8. The turbine trip was actuated as a result of a Turbine Motoring Generator Trip. The cause of the generator trip is unknown at this time and is under investigation. After the Reactor Trip occurred, the 1A Auxiliary Feedwater pump was manually started to provide feedwater flow to all four steam generators. The 1A Auxiliary Feedwater pump was subsequently secured and placed in standby when the Startup Feedwater pump was placed in service. Train A Main Control Room Ventilation Filtration system shifted to Makeup Mode due to a spurious actuation signal. No secondary relief valves lifted and no secondary steam was released as a result of the Reactor Trip. The Main Steam dump valves are in service to the Main Condenser to provide heat sink cooling. The plant is being maintained at normal operating pressure and temperature. AC power is being provided by Offsite Power with the Diesel Generators in standby and all safety systems available. There is no impact to Unit 2. This report is being made per 10 CFR 50.72(b)(2)(iv)(B) for a RPS actuation, 4-hr notification, and per 10 CFR 50.72(b)(3)(iv)(A) for a manual actuation of the Auxiliary Feedwater system, 8-hr notification. The licensee notified the NRC Resident Inspector and Illinois Emergency Management Agency.
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 5335822 April 2018 22:40:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopOn Sunday, April 22, 2018 at 1646 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 1A Diesel Generator (DG) Emergency Core Cooling System (ECCS) Actuation Surveillance, initiating the 1A DG to emergency start and sequence loads on a safety injection signal. Following the 1A DG solely supplying electrical power to Bus 141, the 1A DG lost voltage, resulting in an unplanned UV actuation of ESF Bus 141. The 1A DG output breaker was manually opened and local emergency stop of the 1A DG was attempted. The 1A DG continued to run at idle. Fuel supply was secured to the 1A DG and the engine stopped. Subsequently, operators restored power to ESF Bus 141 from the Unit 1 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 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 5334819 April 2018 23:41:00Indian PointNRC Region 1Westinghouse PWR 4-LoopWhile performing a turbine startup, a turbine control anomaly caused a steam generator level transient. The rise in steam generator level above the setpoint caused the turbine to automatically trip. The high steam generator level of 73 percent caused a feedwater isolation signal at 2107 EDT, which also tripped both Main Boiler Feed Pumps. The tripping of the Main Boiler Feed Pumps auto started the motor driven Aux Boiler Feed Pumps 21 and 23. The reactor was manually tripped at 2108 EDT in accordance with AOP-FW-1 Loss of Main Feedwater. All control rods inserted. Electrical power is being provided from offsite via the Station Aux Transformer. Decay heat removal is being provided via the Atmospheric Dump Valves. An investigation into the cause of the turbine control anomaly is underway. The NRC Resident Inspector has been notified. The event did not have an affect on Unit 3 and there is no primary to secondary leakage.
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 5328826 March 2018 11:51:00Watts BarNRC Region 2Westinghouse PWR 4-LoopAt 1058 Eastern Daylight Time (EDT) on March 26, 2018, a Main Control Room (MCR) alarm was received for low control room positive pressure. At 1100 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 1100 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 1058 EDT to 1100 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). The NRC Resident Inspector has been notified.
ENS 5327019 March 2018 02:27:00SequoyahNRC Region 2Westinghouse PWR 4-LoopOn 3/16/2018 at approximately 1630 EST, an industrial safety accident occurred at Sequoyah Nuclear Plant that involved an Arc Flash injury of two contract employees. While performing work near a non safety related 6.9kV electrical bus, an arc occurred injuring the two employees. Both personnel were transported to an offsite medical facility for treatment. Neither were contaminated. The cause of the arc flash is not understood at this time, an accident investigation has been initiated by TVA. The SQN (Sequoyah Nuclear) NRC Senior Resident Inspector has been notified. No safety related systems required to establish or maintain safe shutdown were affected. Both Unit 1 and 2 remain at 100 (percent) power. TVA has received and responded to media inquiries concerning this event. As a result, this event is considered reportable under 10CFR50.72(b)(2)(xi).
ENS 532401 March 2018 20:34:00McGuireNRC 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 discovered condition affects the functionality of an emergency response facility. Due to the discovery of a breaker coordination issue during an NRC Inspection, the power supply breakers to the Technical Support Center (TSC), including the ventilation system, has been opened to address the condition. This will make the TSC non-functional. If an emergency is declared requiring TSC activation during this period, the Alternate TSC will be staffed and activated using existing emergency planning procedures. The Emergency Response Organization team has been notified to respond to the Alternate TSC in the event of an ERO (Emergency Response Organization) activation. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector 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 5322320 February 2018 18:46:00CallawayNRC Region 4Westinghouse PWR 4-Loop

At 1225 CST, all three Auxiliary Feedwater (AFW) pumps were declared inoperable at the Callaway Plant upon discovery that a door (DSK13311) credited for protection of equipment from the effects of a high-energy line break (HELB) hazard had come partially open due to vibration harmonics from the running turbine-driven Auxiliary Feedwater pump (TDAFP). Immediate investigation identified that play in the mechanism that holds the door closed had rendered it susceptible to movement from the vibration harmonics. The affected HELB door specifically protects safety-related instruments that provide a swap-over signal upon detection of a low suction pressure condition for the AFW pumps and thereby automatically effect a suction transfer for the AFW pumps from the condensate storage tank (normal/standby source) to the Essential Service Water (ESW) system (credited safety-related source). All of the AFW pump suction transfer instrument channels were declared inoperable. Per Technical Specifications (TS) 3.3.2, 'Engineered Safety Feature Actuation System (ESFAS) Instrumentation,' the applicable Condition(s) and Required Action(s) for inoperable AFW pump suction transfer instrumentation only addresses a single channel being inoperable. Thus, the condition of having all three instrument channels inoperable required entry into TS Limiting Condition for Operation (LCO) 3.0.3. At the same time, however, with the automatic suction transfer capability rendered inoperable, all three AFW pumps, i.e., the TDAFP and the 'A' and 'B' motor-driven AFW pumps, were declared inoperable. Although LCO 3.0.3 was applicable, entry into the Required Actions of LCO 3.0.3 was suspended per the Note attached to Required Action E.1 of TS 3.7.5, 'Auxiliary Feedwater (AFW) System,' which states, 'LCO 3.0.3 and all other LCO Required Actions requiring MODE changes are suspended until one AFW train is restored to OPERABLE status.' At 1336 CST, Operations took actions to prevent the TDAFP from running, so the remaining (AFW Pumps) could be returned to Operable status. Operations then declared the affected instrumentation and the 'A' and 'B' motor-driven AFW pumps Operable. This allowed LCO 3.0.3 and Conditions A, B, D, and E under TS 3.7.5 to be exited. With only the TDAFP inoperable, TS 3.7.5 Condition C and its Required Actions remain in effect. Due to the degraded HELB door rendering all three AFW pumps inoperable, the unidentified condition is being reported as an unanalyzed condition that significantly degraded plant safety (per 10 CFR 50.72(b)(3)(ii)(B)) as well as a condition that could have prevented the fulfillment of the safety functions of structures or systems that are needed to shut down the reactor and maintain it in a safe shutdown condition, remove residual heat, and mitigate the consequences of an accident (per 10 CFR 50.72(b)(3)(v)(A), (B), and (D), respectively). The NRC Senior Resident Inspector has been notified.

  • * * RETRACTION ON 4/4/2018 at 1109 EDT FROM JONATHAN LAUF TO DAVID AIRD * * *

Event Notification (EN) # 53223, made on 2/20/2018, is being retracted because new information has been obtained that negates the original basis for reporting the unanalyzed condition. Specifically, an evaluation of the HELB that is postulated to occur in the TDAFP room has determined that without crediting door DSK13311 for protection, the affected safety-related instruments would not be exposed to environmental conditions beyond their analyzed capability. This resulted in a conclusion that the unanalyzed condition of door DSK13311 being open did not prevent the affected safety-related instruments or their supported AFW pumps from performing their required safety functions to shut down the reactor and maintain it in a safe shutdown condition, remove residual heat, and/or mitigate the consequences of an accident, nor did it significantly degrade plant safety. Consequently, the condition did not meet the criteria for an 8-hour notification per 10 CFR 50.72(b)(3)(ii)(B) and 10 CFR 50.72(b)(3)(v)(A), (B), or (D). The licensee notified the NRC Resident Inspector. Notified R4DO (Drake).

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 5321616 February 2018 04:43:00Indian PointNRC Region 1Westinghouse PWR 4-LoopOn February 16, 2018 at 02:01 EST Indian Point Unit 3 automatically tripped on a turbine trip due to a loss of main generator excitation. All control rods fully inserted and all plant equipment responded normally to the unit trip. This is reportable under 10 CFR 50.72(b)(2)(iv)(B). The auxiliary feedwater system actuated following the automatic trip as expected. This is reportable under 10 CFR 50.72(b)(3)(iv)(A). During the event offsite power remained available and stable. No primary or secondary reliefs lifted. The plant is stable, in Mode 3, at no load operating temperature and pressure. Decay heat removal is via the steam generators to the main condenser via the condenser steam dumps. No radiation was released. Indian Point Unit 2 was unaffected by this event and remains at 100 percent power. A post trip investigation is in progress. The licensee has notified the NRC Resident Inspector.
ENS 5321215 February 2018 05:04:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt time 0306 (CST), Main Steamline Radiation Monitor 2-RE-2326 (Main Steamline 2-02) reading spiked and declared non-functional. With this radiation monitor non-functional, all of the emergency action levels for a steam generator tube rupture in steam generator 2-02 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 2-02. Corrective actions are being pursued to restore 2-RE-2326 to functional status. 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 5317317 January 2018 22:41:00Watts BarNRC Region 2Westinghouse PWR 4-LoopAt 2002 EST on January 17, 2018, annulus differential pressure exceeded its pressure limit. At that time, the Shield Building was declared inoperable requiring entry into Technical Specification 3.6.15, Conditions A and B. Action was taken by field operators to swap annulus vacuum control dampers to restore annulus differential pressure. At 2024 EST, annulus differential pressure was restored to required limits, the Shield Building was declared operable, and LCO 3.6.15, Conditions A and B were exited. The temporary loss of the Shield Building resulted from a failure of the annulus vacuum control system to maintain the required differential pressure. Manual swap-over of pressure control to the backup damper restored differential pressure to required limits allowing exit from TS LCO 3.6.15 and restoration of the Shield Building safety function. The Shield Building ensures that the release of radioactive material from the containment atmosphere is restricted to those leakage paths and associated leakage rates assumed in the accident analysis during a Loss of Coolant Accident (LOCA). The Emergency Gas Treatment System (EGTS) would have automatically started and performed its design function to maintain annulus vacuum within required limits. This event is being reported pursuant to 10 CFR 50.72(b)(3)(v)(D). The NRC Resident Inspector has been notified.
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 531546 January 2018 18:14:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 1126 (CST), main steamline radiation monitor 2-RE-2326 (Main Steamline 2-02) reading was determined to be erratic 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 2-02 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 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 (Nitrogen-16) 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 (Main Steam Line) 2-02. Corrective actions are being pursued to restore 2-RE-2326 to functional status. The NRC Resident Inspector has been notified.
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 5311612 December 2017 17:52:00South TexasNRC Region 4Westinghouse PWR 4-LoopA South Texas Project (STP) Offsite Emergency Notification Siren (#7) was inadvertently going off. A resident who lived near the siren notified the Matagorda County Sheriff's Office at 0905 CST of the event and subsequently left a message with the STP Emergency Response staff. The Emergency Response staff dispatched maintenance to repair the siren and then later notified the Control Room at 1519 CST that the Sheriff's department was notified. The siren was inspected and reset. No issues were found with the siren. The Matagorda County Sheriff's Office was the only offsite agency that has been notified. The NRC Resident Inspector has been notified.
ENS 5311211 December 2017 11:06:00Watts BarNRC Region 2Westinghouse PWR 4-LoopWhile operating at 97% power, the Watts Bar Unit 2 reactor was manually tripped at 0857 EST on December 11, 2017 due to multiple dropped control rods. All control and shutdown bank rods inserted properly in response to the manual reactor trip. All safety systems including Auxiliary Feedwater actuated as designed. The plant is stable with decay heat removal through Auxiliary Feedwater and the Steam Dump System. The cause of the dropped rods is being investigated. The manual 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 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. No safety or relief valves lifted during this event.
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).