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 Discovered dateReporting criterionTitleEvent description
ENS 5675927 September 2023 15:41:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(3)(iv)(A), System Actuation
Actuation of Reactor Protection and Containment Isolation Systems

The following information was provided by the licensee via fax: (On 09/27/2023) at 1041 CDT, with the plant at 75 percent power and main turbine control valve testing in progress, a reactor pressure transient resulted in a reactor steam dome high pressure scram and subsequent group 1 primary containment isolation of the main steam lines (MSL). All main steam isolation valves closed as a result of the group 1 isolation signal. Additionally, a group 2 containment isolation signal was received due to reactor pressure vessel (RPV) level less than plus 9 inches during the transient. Operations personnel responded and stabilized the plant. The high-pressure coolant injection (HPCI) system was placed in service to control RPV pressure. HPCI did not inject into the RPV and was not needed to control RPV water level. The cause of the initial pressure transient is under investigation. The NRC Resident Inspector has been notified.

      • UPDATE ON 9/27/2023 AT 2350 EDT FROM NATHAN PIEPER TO LAWRENCE CRISCIONE***

The utility notified the State of Minnesota and Wright and Sherburne counties. Notified R3DO (Orlikowski)

ENS 5667310 August 2023 04:39:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(3)(iv)(A), System Actuation
10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge
Automatic Reactor TripThe following information was provided by the licensee via email: At 0039 (EDT) on 8/10/23, with Unit 1 in Mode 1 at 100 percent power, the reactor automatically tripped during a reactor protection system (RPS) bus shift. All systems responding normally post-trip. There was no equipment inoperable at the time of the trip. Operations responded and stabilized the plant. Reactor water level being maintained via feedwater. Decay heat is being removed by cycling safety relief valves. An actuation of high-pressure core spray, division 3 diesel generator, and reactor core isolation cooling occurred during the scram and main steam line isolation closure. The reason for the auto-start was reaching Level 2 (130 inches in the reactor pressure vessel) during the transient. The systems automatically started as designed and injected to the reactor vessel when the Level 2 signal was received. The RPS actuation is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). The emergency core cooling system (ECCS) injection is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A). The ECCS actuation is being reported as a eight-hour, non-emergency notification per 10 CFR 50.72(b)(2)(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 566501 August 2023 13:55:0010 CFR 50.72(b)(3)(xiii), Loss of Emergency PreparednessActive Seismic Monitoring System InoperableThe following information was provided by the licensee via email: On 08/01/2023 at 0955 EDT, the Fermi 2 active seismic monitoring system provided indication of a potential seismic activity event. Plant abnormal procedures were entered, and compensatory measure were met and remain in place. Neither the (United States Geological Survey) (USGS) nor the next closest nuclear power plant could confirm or validate the readings obtained at Fermi. The seismic monitoring system was declared nonfunctional to validate the calibration of the system. Femi 2 has two active seismic monitors: one on the reactor pressure vessel pedestal and one in the high-pressure core injection (HPCI) room. Only the HPCI room accelerometer was declared inoperable. The HPCI accelerometer is the sole 'trigger' for the seismic recording system, which outputs peak accelerations experienced during a seismic event. This is used in assessment of the magnitude of an earthquake for EAL HU 2.1. The loss of the active seismic monitoring system is reportable to the NRC within 8 hours of discovery in accordance with 10 CFR 50.72(b)(3)(xiii). No seismic activity has been felt onsite and the USGS recorded no seismic activity in the area. The NRC Resident Inspector has been notified.
ENS 562985 January 2023 17:42:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge
Automatic Reactor ScramThe following information was provided by the licensee via phone and email: At 1242 (EST) on 05 January 2023, with the Unit in Mode 1 at 99 percent power, the reactor automatically tripped on low Reactor Pressure Vessel level while restoring power to Digital Feedwater Control Stations when there was a perturbation to the level controls. The reason for perturbation is unknown at this time. The trip was not complex, with all systems responding normally post trip. Operations responded and stabilized the plant. High pressure core spray was manually initiated in accordance with site procedures. Reactor water level is being maintained via the Feedwater System. Decay heat is being removed by the Main Condenser. Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(A) and 10 CFR 50.72(b)(2)(iv)(B). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5627817 December 2022 05:51:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(3)(iv)(A), System Actuation
Manual Reactor ScramThe following information was provided by the licensee via email: On December 16, 2022 at 2351 CST, with the Unit in Mode 1 at 13 percent power, a manual scram was inserted due to lowering Reactor Pressure Vessel (RPV) pressure, which occurred following an unexpected opening of Main Turbine Bypass Valve 1. All control rods fully inserted. Following actuation of the manual scram, RPV pressure lowered, resulting in an automatic Primary Containment lsolation (PCIS) Group 1 isolation (expected response). The main steam isolation valves and steam line drain valves all closed. The Group 1 (isolation) has been reset allowing RPV pressure control with steam line drains to the main condenser. All systems responded as designed. The plant is stable in Mode 3. Investigation of the bypass valve opening is ongoing. This event is reportable under 10 CFR 50.72(b)(2)(iv)(B) RPS Actuation and 50.72(b)(3)(iv)(A) Specified System Actuation. There was no impact on health and safety of the public or plant personnel. The NRC Senior Resident Inspector has been notified.
ENS 5540311 August 2021 10:34:0010 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an AccidentHPCI Inoperability

At 0634 EDT on August 11, 2021 (high pressure coolant injection) HPCI was declared inoperable due to a pump flow controller problem. The cause of the controller problem is unknown at this time and is under investigation. (Reactor core isolation cooling) RCIC was verified operable per Tech Spec 3.5.1 E.1. This report is being made pursuant to 10CFR50.72(b)(3)(v)(D) based on an unplanned HPCI inoperability. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.

  • * * RETRACTION FROM WHITNEY HEMMINGWAY TO KAREN COTTON ON 10/6/2021 AT 1036 EDT * * *

The purpose of this notification is to retract a previous report made on August 11, 2021 (EN 55403). At 0634 EDT on August 11, 2021, an unplanned inoperability of the High Pressure Coolant Injection system (HPCI) was reported pursuant to 10 CFR 50.72(b)(3)(v)(D) by EN 55403. HPCI was declared inoperable due to receipt of an alarm associated with the pump flow controller. The HPCI system operating procedure states that HPCI should be declared inoperable when this alarm is received. The cause of the alarm, a loose transmitter connection, was identified and corrected. Following clearance of the alarm, HPCI was declared operable at approximately 1930 EDT on August 11, 2021. This alarm indicated a fault in the signal from the transmitter to the HPCI flow controller; in this case, the HPCI flow controller would have continuously called for maximum HPCI flow. The controller is configured with a high limiter to prevent an overspeed trip. An engineering evaluation of the event identified that HPCI was capable of performing its required safety functions while this alarm was present. The condition was that the HPCI flow controller would have continuously called for maximum HPCI flow upon HPCI initiation, however operators would be able to manually control HPCI flow upon HPCI initiation. Additionally HPCI would have run until Reactor Pressure Vessel (RPV) level reached Level 8 where it would trip until RPV level decreased to Level 2 then automatically restart. The licensee notified the NRC Resident Inspector. Notified R3DO (Peterson).

ENS 5497129 October 2020 14:30:0010 CFR 50.72(b)(3)(ii)(A), Seriously DegradedThrough-Wall Leakage Identified on Reactor Coolant System Pressure Boundary During TestingAt 1030 EDT on Thursday, October 29, 2020, during the performance of Peach Bottom Atomic Power Station leakage testing of the reactor pressure vessel and associated piping, a through-wall leak (non-isolable) was identified on an instrument line connected to the N16A nozzle. The reactor will be maintained shutdown until pipe repairs and testing are complete. The NRC resident inspector has been informed.
ENS 5450331 January 2020 10:55:0010 CFR 50.72(b)(2)(iv)(B), RPS System ActuationAutomatic Reactor Scram Due to Main Turbine TripAt 0555 (EST), on January 31, 2020, James A. FitzPatrick was at 38 percent power when an automatic scram occurred as a result of a main turbine trip on high Reactor Pressure Vessel (RPV) water level. The plant was at reduced power in preparation for maintenance activities. The 'A' Reactor Feed Pump (RFP) was being removed from service when a perturbation in reactor water level reached the high RPV water level setpoint. This resulted in a main turbine trip and 'B' RFP trip. The automatic scram inserted all control rods. A subsequent low water level resulted in a successful Group 2 isolation. The plant is stable in Mode 3 with the 'B' RFP maintaining RPV water level. The initiation of the reactor protection systems (RPS) due to the automatic scram signal at critical power is reportable per 10 CFR 50.72(b)(2)(iv)(B) and 10 CFR 50.72(b)(3)(iv)(A). The general containment Group 2 isolations are reportable per 10 CFR 50.72(b)(3)(iv)(A). The licensee notified the NRC Resident Inspector, and the State and Local government for the scram. Decay heat is being removed via the main condenser.
ENS 5418527 July 2019 23:29:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge
Automatic Reactor Scram Due to Main Turbine TripAt 1929 EDT on 7/27/2019, with the Unit in Mode 1 at 98 percent power, the reactor automatically scrammed due to a Main Turbine Trip. The trip was not complex, with all systems responding normally post-trip. Main Steam Isolation Valves (MSIVs) were manually closed to prevent exceeding Reactor Pressure Vessel Cooldown Rate. Rector Core Isolation Cooling (RCIC) was manually initiated to stabilize Reactor Vessel Water Level and Pressure following MSIV closure. The Main Condenser and Feedwater are available. Operations responded and stabilized the plant. Reactor water level is being maintained via RCIC. Decay heat is being removed by discharging steam to the Main Condenser and RCIC. The cause of the Main Turbine Trip is currently under investigation. The site is in a normal electrical lineup. The licensee notified the NRC Resident Inspector.
ENS 5403529 April 2019 20:33:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(3)(iv)(A), System Actuation
Manual Reactor Scram Due to Power Oscillations and High Pressure Coolant Injection System InitiationDuring power ascension on April 29, 2019, at 1630 (EDT), Nine Mile Point Unit 1 power and pressure oscillations were observed with reactor power at approximately 82 (percent). At time 1633 (EDT), the reactor was manually scrammed when the scram criteria of greater than 4 (percent) APRM power oscillations were observed in accordance with special operating procedures. All control rods fully inserted and all plant systems responded per design following the scram. Following the manual scram, the High Pressure Coolant Injection (HPCI) System automatically initiated as expected. At Nine Mile Point Unit 1, a HPCI system actuation signal on low Reactor Pressure Vessel (RPV) level is normally received following a reactor scram, due to level shrink. HPCI is a flow control mode of the normal feedwater systems, and is not an Emergency Core Cooling System. At 1633 (50 seconds after the reactor scram), RPV level was restored above the HPCI System low level actuation setpoint and the HPCI System initiation signal was reset. Pressure control was established on the Turbine Bypass Valves, the preferred system. No Electromatic Relief Valves actuated due to this scram. Nine Mile Point Unit 1 is currently in Hot Shutdown, with reactor water level and pressure maintained within normal bands. The offsite grid is stable with no grid restrictions or warnings in effect. The cause of the power oscillations is currently under investigation. The NRC Resident Inspector was notified. The New York State public service commission was notified.
ENS 5399814 April 2019 04:03:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(3)(iv)(A), System Actuation
Automatic Reactor Scram and Specified System ActuationOn April 14, 2019 at 0003 (EDT), Nine Mile Point Unit 1 experienced an automatic reactor scram during reactor startup. The cause of the automatic scram was due to high (Reactor Pressure Vessel) pressure following closure of the turbine stop valves. All control rods fully inserted and all plant systems responded per design following the scram. Following the automatic scram, the High Pressure Coolant Injection (HPCI) System automatically initiated as expected. At Nine Mile Point Unit 1, a HPCI System actuation signal on low Reactor Pressure Vessel (RPV) level is normally received following a reactor scram, due to level shrink. HPCI is a flow control mode of the normal feedwater systems, and is not an Emergency Core Cooling System. At 0004, RPV level was restored above the HPCI System low level actuation set point and the HPCI System initiation signal was reset. Pressure control was established on the Turbine Bypass Valves, the preferred system. No Electromatic Relief Valves actuated due to this scram. Nine Mile Point Unit 1 is currently in Hot Shutdown, with reactor water level and pressure maintained within normal bands. The offsite grid is stable with no grid restrictions or warnings in effect. The unit is currently implementing post scram recovery procedures. The NRC Resident Inspector has been notified. The Licensee will notify the State of New York.
ENS 5382514 January 2019 05:00:0010 CFR 50.72(b)(3)(xiii), Loss of Emergency PreparednessActive Seismic Monitoring System Inoperable

On 01/11/2019 at 0958 EST, the Fermi 2 Active Seismic Monitoring system was taken out of service for planned maintenance. During the maintenance activity, the Active Seismic Monitoring System failed a planned surveillance test and was not restored to operability within 72 hours. Compensatory measures to provide alternative methods for event classification of a seismic event were implemented in accordance with the Fermi 2 Emergency Plan procedures prior to the start of the planned maintenance outage. The planned outage time to restore operability exceeded 72 hours on January 14th, 2019, at 0958 EST. Repairs have been completed, the Active Seismic Monitoring System has been declared Functional at 1037 EST, January 14th, 2019, and declared Operable at 1109 EST, January 14th, 2019.

The loss of the Active Seismic Monitoring System is reportable to the NRC within 8 hours of discovery in accordance with 10 CFR 50.72(b)(3)(xiii). No seismic activity has been felt onsite and the United States Geological Survey (USGS) recorded no seismic activity in the area. The NRC Resident Inspector has been notified. Femi 2 has two seismic monitors, one on the Reactor Pressure Vessel Pedestal and one in the High Pressure Core Injection (HPCI) room. Only the HPCI room monitor was inoperable.

ENS 5358419 March 2018 04:00:0010 CFR 50.73(a)(1), Submit an LERInvalid Specified System ActuationPursuant to 50.73(a)(1) the following information is provided as a sixty (60) day telephone notification to the NRC. This notification, reported under 50.73(a)(2)(iv), is being provided in lieu of the submittal of a written LER (Licensee Event Report) to report a condition that resulted in an invalid actuation of the high pressure coolant injection (HPCI). At Nine Mile Point Unit 1, HPCI is a flow control mode of the normal feedwater system and is not an emergency core cooling system. On March 19, 2018 Nine Mile Point Unit 1 (NMP1) was at 0 percent power and in cold shutdown in support of a planned maintenance outage. At approximately 0118 (EDT), a reactor water level transient initiated by the fill and vent of 12 Reactor Recirculation Pump (12 RRP) occurred. During the fill and vent, Reactor Pressure Vessel (RPV) level lowered quickly from the initial level of 68 inches and a low level alarm was received. Control Room Operators reduced Reactor Water Clean-Up (RWCU) reject flow to turn the level trend and clear the low level alarm generated off of the compensated, GEMAC, level instrumentation. RWCU reject flow was reduced by 50 percent which caused RPV level to start to rise. RPV level was raised to approximately 72 inches at which time the Reactor Operator began to raise reject flow to reestablish the normal level band. During the RPV level transient, with actual water level at 74 inches on the GEMAC, the Yarway level instrumentation, which is not density compensated and therefore invalid, reached 92 inches causing an invalid high RPV water level turbine trip signal and associated invalid HPCI initiation signal. At no point in time did actual RPV water level reach the high RPV water level turbine trip set point of 92 inches. The potential for a turbine trip signal to occur due to shutdown activities was understood and tags were hung to lockout the Feedwater Pumps to prevent the HPCI start signal. Therefore, no HPCI injection occurred. The Licensee has notified the NRC Resident Inspector.
ENS 5341018 May 2018 13:51:0010 CFR 50.72(b)(2)(iv)(B), RPS System ActuationAutomatic Reactor Scram Caused by Main Transformer TripAt 0651 (PDT) on May 18th, 2018, Columbia Generating station experienced a Main Transformer trip, that caused a Reactor Scram. Reactor Power, Pressure and Level were maintained as expected for this condition. MS-RV-1A (Safety Relief Valve) and MS-RV-1B (Safety Relief Valve) opened on reactor high pressure during the initial transient. MS-RV-1B appeared to remain open after pressure lowered below the reset point. The operating crew removed power supply fuses for MS-RV-1B and it currently indicates intermediate position. SRV (Safety Relief Valve) tail pipe temperatures indicate all valves are closed. Suppression pool level and temperature have remained steady within normal operating levels. All control rods inserted and reactor power is being maintained subcritical. RPV (Reactor Pressure Vessel) water level is being maintained with condensate and feed system with startup flow control valves in automatic. Reactor Pressure is being maintained with the Turbine Bypass valves controlling in automatic. The main condenser is the heat sink. No ECCS (Emergency Core Cooling Systems) systems actuated or injected; the EOC-RPT (End of Cycle-Recirculation Pump Trip) and RPS (Reactor Protection System) systems actuated causing a trip of the RRC pumps and a reactor scram. Core recirculation is being maintained with RRC-P-1A (Reactor Recirculation Pump) running. No release has occurred. At this time there will be no notifications to state, local or other public agencies. The NRC Senior Resident has been notified. The cause of the event is currently under investigation. Plant conditions are stable. The plant is in its normal electrical alignment and offsite power is available to the site.
ENS 533741 May 2018 20:51:0010 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat
10 CFR 50.72(b)(3)(iv)(A), System Actuation
10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge
Plant Received Division One Reactor Pressure Vessel Level 1 SignalAt 1551 hrs (CDT) on 5/1/2018, with the plant in Mode 5, a division one Reactor Pressure Vessel (RPV) Level 1 signal was received; however there was no actual change in RPV level. RPV Level remained at High Water Level supporting refuel operations. This caused an actuation of division one Load Shed and Sequencing system that shed and then re-energized the 15 bus. Division one diesel generator started from standby. Residual Heat Removal pump 'A', which was in shutdown cooling mode, was lost during the bus shed, and was re-sequenced upon re-energization of the 15 bus. Upon restoration of shutdown cooling, the RHR pump discharged into the RPV. RCS temperature increased approximately 5 degrees Fahrenheit as a result of the loss of shutdown cooling. The cause of the actuation signal is under investigation. In accordance with NUREG 1022, Event Reporting Guidelines, this event is conservatively reported under 10 CFR 50.72(b)(2)(iv)(A) as an event that results in emergency core cooling system discharge into the RCS as a result of a valid signal, under 10 CFR 50.72(b)(3)(iv)(B)(8) as an event that results in the actuation of emergency ac electrical power systems, and under 10 CFR 50.72(b)(3)(v)(B) as an event or condition that at the time of discovery could have prevented the fulfillment of a safety function (remove residual heat). The licensee notified the NRC Resident Inspector.
ENS 5286925 May 2017 23:47:0010 CFR 50.73(a)(1), Submit an LERInvalid High Pressure Core Spray (Hpcs) System Actuation in Mode 5At 1647 (PDT) on May 25, 2017, during the performance of a post-maintenance test for replacement of a Reactor Pressure Vessel (RPV) low water level 3 indicator switch (MS-LIS-24A), a pressure perturbation in the common pressure reference line resulted in tripping of the RPV Level 2 instruments and an unplanned start of High Pressure Core Spray (HPCS) pump (HPCS-P-1) and its supporting emergency diesel (DG3). The Reactor Pressure Vessel was flooded up during the refueling outage, thus, the actuations of the HPCS pump and its supporting emergency diesel (DG3) were unplanned and invalid. The HPCS pump did not inject into the RPV due to the RPV level being above Level 8 which is an interlock to close the HPCS RPV injection valve (HPCS-V-4). During the event, the single train HPCS system initiated normally but did not inject into the reactor pressure vessel as expected due to flooded-up conditions of the reactor pressure vessel for refueling outage activities. The emergency diesel generator started normally in response to the initiation signal of HPCS. Both HPCS and the emergency diesel generator functioned successfully. All systems responded in conformance with their design and there was no safety significance associated with this event. At the time of the event, the licensee notified the NRC Resident (Inspector).
ENS 527388 May 2017 13:25:0010 CFR 50.72(b)(3)(ii)(A), Seriously DegradedThrough-Wall Leakage Identified on Reactor Coolant System Pressure Boundary During TestingOn May 8th, 2017 at 0925 (EDT), during the performance of LGS (Limerick Generating Station) leakage testing of the reactor pressure vessel and associated piping, a through-wall leak was identified on an instrument line connected to the N16D nozzle. The reactor will be maintained shutdown until pipe repairs and testing are complete. The licensee informed the NRC Resident Inspector.
ENS 527242 May 2017 21:00:0010 CFR 50.72(b)(3)(ii)(B), Unanalyzed ConditionUnanalyzed Condition for Combustion Turbine Generator Configuration

On May 2, 2017, while performing a past operability review associated with Combustion Turbine Generator (CTG) 11-1, it was determined that a past configuration of CTG 11-1 could not have assured all of the applicable Appendix R success criteria under all of the postulated scenarios described in the Updated Final Safety Analysis Report (UFSAR). From November 21, 2016 until March 18, 2017 when Mode 4 was entered, CTG 11-1 was in a configuration where it could not be started from the dedicated shutdown panel, although it could be started locally. One of the specific scenarios for Appendix R in the UFSAR credits CTG 11-1 to support a safe shutdown based on an assumed time required to start CTG 11-1 and then provide flow to the reactor pressure vessel using the Standby Feedwater System. During the time period where CTG 11-1 could only be started locally, this assumed time would have been exceeded. Therefore, this event is being reported as an 'unanalyzed condition that significantly affects plant safety' under 50.72(b)(3)(ii)(B). At the time of discovery, CTG 11-1 was fully operable and the described condition had already been corrected. The NRC Resident Inspector has been notified.

  • * * RETRACTION PROVIDED BY GREG MILLER TO JEFF ROTTON AT 1532 EDT ON 05/19/2017 * * *

The purpose of this notification is to retract a previous report made on May 2, 2017 (EN 52724) under 10 CFR 50.72(b)(3)(ii)(B). The notification to the NRC involved an event where Combustion Turbine Generator (CTG) 11-1 could only be started locally such that required operator actions during an Appendix R safe shutdown scenario could be delayed. Subsequent to the initial notification, the event, additional site documentation, and the NRC guidance in NUREG-1022 pertaining to 10 CFR 50.72(b)(3)(ii)(B) were reviewed further. lt was verified that Fermi 2 procedures contained actions to ensure Appendix R safe shutdown capability under the plant conditions during the relevant time period. A time validation study was performed (May 9, 2017) which verified that the operator actions could have been completed within the time described in the Updated Final Safety Analysis Report (UFSAR) for initiating Standby Feedwater flow to the reactor pressure vessel. In addition, a review of the supporting design calculation identified margin in the required time described in the UFSAR. Based on this information, the condition of CTG 11-1 during the time period from November 21, 2016 until March 18, 2017 would not have prevented compliance with the Appendix R safe shutdown requirements. Under these circumstances, the event does not represent an 'unanalyzed condition that significantly affects plant safety' under 10 CFR 50.72(b)(3)(ii)(B) per the guidance in NUREG-1022. Therefore, EN 52724 can be retracted and no Licensee Event Report (LER) under 10 CFR 50.73(a)(2)(ii)(B) is required to be submitted. The licensee has notified the NRC Resident Inspector. Notified R3DO (Cameron).

ENS 5242510 December 2016 13:48:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(3)(iv)(A), System Actuation
Manual Reactor Scram Due to High Main Turbine VibrationsOn December 10, 2016 at 0848 EST, (operators at) Nine Mile Point Unit 1 manually scrammed the reactor due to high vibrations on the Main Turbine. Cause of the high vibrations is being investigated. Following the scram, the High Pressure Coolant Injection (HPCI) system automatically initiated as expected. At Nine Mile Point Unit 1, a HPCI system actuation signal on low reactor pressure vessel (RPV) level is normally received following a reactor scram, due to level shrink. HPCI is a flow control mode of the normal feedwater system and is not an emergency core cooling system. At 0849, RPV level was restored above the HPCI system low level actuation set point and the HPCI system initiation signal was reset. Pressure control was established on the turbine bypass valves, the preferred system. No Electromatic relief valves actuated due to this scram. Nine Mile Point Unit 1 is currently in Hot Shutdown, with reactor water level and pressure maintained within normal bands. Decay heat is being removed via steam to the main condenser using the bypass valves. The offsite grid is stable with no grid restrictions or warnings in effect. The unit is currently implementing post scram recovery procedures. The licensee has notified the state of New York Public Service Commission and the NRC Resident Inspector.
ENS 5204224 June 2016 16:15:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(3)(iv)(A), System Actuation
Manual Reactor Scram Due to Reactor Recirculation Pumps DegradationAt 1215 (EDT) on 6/24/2016, James A. FitzPatrick (JAF) was at 100% power when Breaker 710340 tripped and power was lost to L-gears L13, L23, L33, and L43. These provide non-vital power to Reactor Building Ventilation (RBV), portions of Reactor Building Closed Loop Cooling (RBCLC), and 'A' Recirculation pump lube oil systems. Off-site AC power remains available to vital systems and Emergency Diesel Generators (EDG) are available. Due to the loss of RBV, Secondary Containment differential pressure increased. At 1215 (EDT), Secondary Containment differential pressure exceeded the Technical Specifications (TS) Surveillance Requirement SR-3.6.4.1.1 of greater than or equal to 0.25 inches of vacuum water gauge. The Standby Gas Treatment (SBGT) system was manually initiated and Secondary Containment differential pressure was restored by 1219 (EDT). The 'A' Recirculation pump tripped at 1215 (EDT) and reactor power decreased to approximately 50%. 'B' Recirculation pump temperature began to rise due to the degraded RBCLC system. At 1236 (EDT), a manual scram was initiated. Reactor Pressure Vessel (RPV) water level shrink during the scram resulted in a successful Group 2 isolation. All control rods have been inserted. The RPV water level is being maintained with the Feedwater System and pressure is being maintained by main steam line bypass valves. A cooldown is in progress and JAF will proceed to cold shutdown (Mode 4). Due to complete loss of RBCLC system, the Spent Fuel Pool (SFP) cooling capability is degraded but the Decay Heat Removal system remains available. SFP temperature is slowly rising and it is being monitored. The time (duration) to 200 degrees is approximately 117 hours. The initiation of reactor protection systems (RPS) due to the manual scram at critical power is reportable per 10 CFR 50.72(b)(2)(iv)(B) and 10 CFR 50.72(b)(3)(iv)(A). The general containment Group 2 isolations are reportable per 10 CFR 50.72(b)(3)(iv)(A). In addition, the temporary differential pressure change in Secondary Containment is reportable per 10 CFR 50.72(b)(3)(v)(C), as an event that could have prevented fulfillment of a safety function. The licensee notified the NRC Resident Inspector and the State of New York.
ENS 5156424 November 2015 11:34:0010 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual HeatResidual Heat Removal Pump Tripped During Initiation of Shutdown CoolingOn 11/24/2015 at 0534 hours (CST) the plant was in MODE 3 (hot standby) for a forced outage. While initially placing Shutdown Cooling (SDC) in service, the 12 Residual Heat Removal (RHR) pump tripped approximately 8-10 seconds after start due to the closure of the RHR SDC suction isolation valves. This was determined to be from an invalid signal on the Reactor Pressure Vessel (RPV) suction interlock. This is being reported under 10 CFR 50.72 (b)(3)(v)(B) as an event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to remove residual heat. This event did not challenge the ability to maintain safe shutdown conditions, remove residual heat, control the release of radioactive material, or mitigate the consequences of an accident as other methods of decay heat removal were being utilized successfully to establish plant conditions. The NRC Resident Inspector has been notified. This incident places the RHR system in a 24-hour technical specification limiting condition for operations.
ENS 514494 October 2015 13:56:0010 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive MaterialSecondary Containment Inoperable with the Potential to Drain the Reactor VesselOn October 4th, at approximately 0956 EDT, 'Operations with the Potential to Drain the Reactor Pressure Vessel' (OPDRV) was unintentionally initiated without secondary containment operable. Operators promptly identified the condition and immediately initiated actions to identify and suspend the source of the drain path. At approximately 1120 EDT the source of the OPDRV was isolated. Reactor cavity water level and spent fuel pool level remained constant throughout the event. An investigation is in progress. The NRC Resident Inspector has been notified.
ENS 5143229 September 2015 14:30:0010 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive MaterialBoth Trains of the Standby Gas Treatment System Declared InoperableOn 9/29/15 at 1020 EDT, the 'B' train of Standby Gas Treatment System was declared inoperable for planned testing. On 9/29/15 at 1030 EDT, during performance of a surveillance on Unit 1 Reactor Pressure Vessel water level instrumentation, one channel was found to not meet acceptance criteria. The failed level channel is part of the initiation logic for the 'A' train of Standby Gas Treatment. This resulted in a loss of safety function for the Standby Gas Treatment System. On 9/29/15 at 1145 EDT, the 'B' train of Standby Gas Treatment was restored to operable by restoring from the planned testing. This event is being reported under 10 CFR 50.72(b)(3)(v)(c) and per the guidance of NUREG 1022 Rev 3 section 3.2.7 as a loss of a Safety Function. The NRC Resident Inspector has been informed.
ENS 5139114 September 2015 03:05:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(3)(iv)(A), System Actuation
10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material
Manual Scram Due to Loss of Turbine Building Closed Cooling Water

At 2305 EDT on September 13, 2015, a manual scram was initiated in response to a loss of all Turbine Building Closed Cooling Water (TBCCW). All control rods fully inserted. The lowest Reactor Water Level (RWL) reached was 137 inches. All isolations and actuations for RWL 3 occurred as expected. Decay heat was initially being removed through the Main Turbine Bypass System to the Main Condenser, however, as a result of the loss of TBCCW, the Main Feed Pumps lost cooling and had to be secured. At 2310, Standby Feedwater was initiated and Main Feedwater was secured. The loss of TBCCW also caused all Station Air Compressors (SACs) to trip on loss of cooling. The loss of SACs caused the Instrument Air header pressure to degrade to the point at which the Secondary Containment isolation dampers drifted closed. This resulted in the Reactor Building vacuum exceeding the Technical Specification limit. At 2325, operators started the Standby Gas Treatment system and manually initiated a Secondary Containment isolation signal. Secondary Containment vacuum was promptly restored to within Technical Specification limits. Additionally, Operators were monitoring for expected MSIV drift due to the degraded Instrument Air header pressure. When outboard MSIVs were observed to be drifting, Operators closed the outboard and inboard MSIVs at 2345. At 2352, Safety Relief Valves (SRVs) reached the Low-Low Setpoint and began cycling to control reactor pressure. RWL is currently being maintained in the normal level band with the Standby Feedwater and Control Rod Drive systems. Reactor Pressure is being controlled with Safety Relief Valves. Operators are currently in the Emergency Operating Procedure for Reactor Pressure Vessel control. Investigation into the loss of TBCCW continues. No safety-related equipment was out of service at the time of the event. All offsite power sources were adequate and available throughout the duration of the event. The NRC resident inspector has been notified.

  • * * UPDATE AT 0555 EDT AT 09/14/15 FROM CHRIS ROBINSON TO JEFF HERRERA * * *

At 0409 EDT the Reactor Core Isolation Cooling (RCIC) system was placed in service due to identification of an unisolable leak in the Standby Feedwater System. Reactor water level and pressure is now being controlled though the RCIC system and Safety Relief Valves. This event update is reportable as a valid manual initiation of a specified safety system under 10CFR50.72(b)(3)(iv)(A). The NRC resident inspector has been notified. The leak rate was reported as approximately 5-10 gallons per minute from a weld on the standby feedwater pump header drain valve F326. The licensee reported the leak stopped once RCIC was placed into service. The licensee is still investigating the issue. Notified the R3DO (Pelke), IRD Manager (Grant), NRR EO (Morris).

  • * * UPDATE PROVIDED BY CHRIS ROBINSON TO JEFF ROTTON AT 2135 EDT ON 09/14/2015 * * *

At 1847 EDT on September 14, 2015, a valid automatic Reactor Protection System (RPS) actuation occurred due to Reactor Water Level 3 while shutdown in MODE 3. Operators were manually controlling Reactor Pressure Vessel (RPV) level and pressure with Reactor Core Isolation Cooling (RCIC) and Safety Relief Valves (SRV). While operators were cycling SRVs, the RPV level went below the Level 3 setpoint. Operators promptly restored RPV level by manual operation of RCIC. The Level 3 actuation and associated isolations were verified to operate properly. The scram signal has been reset. Fermi 2 remains in MODE 3 controlling RPV Level and Pressure through manual operation of RCIC and SRVs. This is the second occurrence of a valid specified safety system actuation reportable under 10CFR50.72(b)(3)(iv)(A) for this ongoing event. The NRC Resident Inspector has been notified. Notified R3DO (Riemer), IRD Manager (Grant), and NRR EO (Morris)

  • * * UPDATE FROM BRETT JEBBIA TO JOHN SHOEMAKER AT 1446 EST ON 2/27/16 * * *

This update provides clarification of the applicable reporting criteria for this Event associated with primary containment isolation actuations. Upon the manual reactor scram at 2305 EDT on September 13, 2015, Reactor Protection System (RPS) Level 3 actuated and Primary Containment Isolation System (PCIS) Groups 4, 13 and 15 actuated as expected. The applicable reporting criterion for these actuations is 10 CFR 50.72(b)(3)(iv)(A). The applicable reporting criterion for the manual closure of the inboard and outboard main steam isolation valves at 2345 EDT on September 13, 2015, is also 10 CFR 50.72(b)(3)(iv)(A). In addition, the manual closures of all MSIV lead to a loss of condenser vacuum which resulted in the actuation of PCIS Group 1 at 0001 EDT on September 14, 2015, as expected. The applicable reporting criterion for this actuation is also 10 CFR 50.72(b)(3)(iv)(A). Upon reaching Level 3 at 1847 EDT on September 14, 2015, PCIS Groups 4, 13 and 15 actuated as expected. The applicable reporting criterion for this actuation is 10 CFR 50.72(b)(3)(iv)(A). The licensee informed the NRC Resident Inspector. Notified the R3DO (Stone).

ENS 5129823 October 2013 16:00:0010 CFR 21.21(d)(3)(i), Failure to Comply or DefectPart 21 - Damaged Surveillance CapsulesIn April 2015, during Sequoyah Nuclear Plant Unit 1 end of cycle 20 refueling outage, the Tennessee Valley Authority (TVA) identified that there was unanticipated damage to the 'S' and 'W' surveillance capsules that were located within the reactor pressure vessel. Inspections determined that the surveillance capsules were not contained within the intact designated baskets. TVA conducted an extensive foreign object search and recovery initiative to recover the specimen capsule contents prior to concluding the refueling outage. During the October 2013 Sequoyah Unit 1 refueling outage, the Westinghouse Electric Company (WEC) relocated the above referenced surveillance capsules in accordance with Westinghouse procedure MRS-SPP-2970. The procedure specified the requirements for performing specimen capsule relocations. WEC created a deviation when an inadequate procedure referenced in the applicable purchase order, which did not ensure proper seating of the sample capsule, was used at Sequoyah Nuclear Plant Unit 1. TVA considers the above condition to be reportable pursuant to 10 CFR 21.21 as a defect associated with a condition that, if uncorrected, could have created a substantial safety hazard." The NRC Resident Inspector and the vendor were notified.
ENS 5118226 June 2015 05:00:0010 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the ReactorTwo Reactor Vessel Level Channels Failed HighAt 2200 PDT during startup from refueling outage 22, it was discovered that both level instruments used in reactor protection system (RPS) trip system 'A' for initiation of a reactor scram on low reactor pressure vessel (RPV) level were observed to have failed high. This resulted in the inability to generate a full reactor scram on low level (+13 inches). All remaining RPV level indications demonstrated that level was being maintained within normal operating bands. This constitutes a condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to shut down the reactor. The RPS trip logic at Columbia consists of two trip systems, RPS trip system 'A' and RPS trip system 'B'. There are two level instrument channels in each trip system. Columbia utilizes a 'one-out-of-two taken-twice' trip logic to generate a full scram signal. At least one channel in both trip systems must actuate to generate a full scram signal. With both level instruments in RPS system 'A' failed high, the RPS trip logic was unable to generate a full scram. At 2246 (PDT) and in accordance with TS LCO 3.3.1.1 Condition C, a half scram was generated on RPS trip system 'A' to restore full scram capability. The cause of the failure of the two level instruments associated with RPS Trip system 'A' is under investigation. The level channels are being calibrated prior to changing to mode 1 (power operations). The licensee will notify the NRC Resident Inspector.
ENS 5090319 March 2015 11:02:0010 CFR 50.72(b)(2)(iv)(B), RPS System ActuationAutomatic Reactor Scram Due to an Oscillation Power Range Monitor Upscale ActuationAt 0702 EDT on March 19, 2015, Fermi 2 received an automatic scram due to actuation of the Reactor Protection System (RPS) function of Oscillation Power Range Monitor (OPRM) Upscale. The plant had recently transitioned to Single Loop Operation after securing the 'A' Reactor Recirculation Pump due to loss of normal and emergency cooling water supply. The lowest reactor water level was 134 inches above top of active fuel. Reactor water level is being maintained in the normal band by the Feedwater and Control Rod Drive Systems. No Safety Relief Valves (SRV) actuated. Reactor pressure is being maintained via the Main Turbine Bypass Valves and Main Condenser. Reactor Pressure Vessel Level 3 isolation occurred. No additional safety system actuations occurred. All off-site power sources were available throughout the event. The plant is currently in Mode 3 and in a stable condition. Investigation into the cause of the event is ongoing. This event is being reported under the four hour Non-Emergency reporting criteria of 10CFR50.72(b)(2)(iv)(B). The NRC Resident Inspector has been notified.
ENS 5075426 November 2014 20:27:0010 CFR 50.73(a)(1), Submit an LERInvalid Actuation of a General Containment Isolation Signal Affecting More than One SystemThis 60-day telephone notification is being made per the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation of a general containment isolation signal affecting more than one system. On November 26, 2014, at approximately 1427 hours Central Standard Time (CST), the Browns Ferry Nuclear Plant (BFN), 1A Reactor Protection System (RPS) Motor-Generator (MG) Set Power Supply unexpectedly de-energized resulting in a BFN Unit 1 half scram and Primary Containment Isolation System (PCIS) Groups 1, 2, 3, 6, and 8 isolation signals. The PCIS Groups 1, 2, 3, 6, and 8 isolations caused the initiation of all three trains of the Standby Gas Treatment (SBGT) system and Control Room Emergency Ventilation (CREV) subsystem 'A', and isolations of the BFN, Unit 1, Reactor Zone ventilation and BFN, Units 1 and 2, Refuel Zone ventilation (Unit 3 Refuel Zone ventilation was tagged out under 3-TO-2014-0001 at the time of this event). Operations personnel responded to the PCIS initiation, ensured all equipment operated as designed, placed the BFN 1A RPS on alternate power, and reset the RPS logic and PCIS isolations. Plant conditions which initiate PCIS Group 1 actuations are Reactor Pressure Vessel (RPV) Low Low Low Water Level (Level 1), Main Steam Line (MSL) High Flow, MSL Area High Temperature, or MSL Low Pressure. Plant conditions which initiate PCIS Group 2 actuations are Reactor Vessel Low Water Level (Level 3) or High Drywell Pressure. The PCIS Group 3 actuations are initiated by Reactor Vessel Low Water Level (Level 3) or Reactor Water Cleanup Area High Temperature. The PCIS Group 6 actuations are initiated by Reactor Vessel Low Water Level (Level 3), High Drywell Pressure, or Reactor Building Ventilation Exhaust High Radiation (Reactor Zone or Refuel Zone). The PCIS Group 8 actuations are initiated by Low Reactor Vessel Water Level (Level 3) or High Drywell Pressure. At the time of the event, these conditions did not exist; therefore, the actuation of the PCIS was invalid. The apparent cause for this condition was an intermittent problem with the BFN 1A RPS MG Set voltage adjust potentiometer. There were no safety consequences or impact to the health and safety of the public as a result of this event. This event was entered into the Corrective Action Program as Problem Evaluation Report 961518. The NRC Resident Inspector has been notified of this event.
ENS 5067512 December 2014 21:00:0010 CFR 50.72(b)(3)(ii)(B), Unanalyzed ConditionUnanalyzed Condition with Reactor Core Isolation CoolingEngineering identified fuse and breaker coordination issues with Reactor Core Isolation Cooling (RCIC) valves operated at the Remote Shutdown Panel (RSDP). The coordination issues are such that, given a fire in the main control room, it is possible that RCIC valve power supply breakers could trip prior to tripping control power fuses. Operation of RCIC from the RSDP could be impaired in this scenario without compensatory actions to reset breakers. RCIC is the single credited source of makeup to the reactor pressure vessel during this scenario. The current licensing basis (Fire Protection Report) does not identify the compensatory actions required to reset breakers prior to RCIC operation at the RSDP. This condition is applicable to Unit 1 and Unit 2. This report is being made pursuant to 10CFR50.72(b)(3)(ii)(B), 'Event or Condition that results in an unanalyzed condition that significantly degrades plant safety'. Actions are being taken to amend the appropriate operating procedures to take the required steps to ensure proper operation of RCIC in the postulated scenario. The licensee has notified the NRC Resident Inspector.
ENS 4963213 December 2013 23:57:0010 CFR 50.72(b)(2)(iv)(B), RPS System ActuationManual Reactor Trip During Feed Pump SwapDuring a feed pump shift from the motor driven reactor feed pump to the 'A' turbine driven reactor feed pump during power ascension, reactor pressure vessel (RPV) water level was approaching the Reactor Protective System (RPS) automatic scram set point when a manual reactor scram was inserted. All control rods fully inserted. RPV water level is being maintained by the normal condensate booster / feedwater systems. RPV pressure is being maintained via normal main steam system. There were no actuations of any Emergency Core Cooling System and no Safety Relief Valves actuations. All systems responded as expected. The licensee notified the NRC Resident Inspector.
ENS 4958526 November 2013 20:00:0010 CFR 50.72(b)(3)(ii)(A), Seriously DegradedLeakage Discovered on Electromatic Relief Valve During Hydrostatic TestingOn November 26, 2013, with Unit 2 shutdown for refueling, leakage was identified on the 2-0203-3C Electromatic Relief Valve (ERV) during a Reactor Pressure Vessel (RPV) pressure test. The leak is located on the line connecting the ERV main body to the pilot valve, and is approximately 1 drop per second. Each unit is designed with relief valves which actuate to control reactor coolant system pressure during transient conditions and are located on the main steam lines between the reactor vessel and the first isolation valve within the drywell. The cause of this event is under investigation. The condition is being reported under 50.72(b)(3)(ii)(A) given the defect was associated with the primary coolant system pressure boundary. The NRC Resident Inspector has been notified.
ENS 4935318 September 2013 10:10:0010 CFR 50.72(b)(3)(ii)(A), Seriously DegradedBoroscopic Inspection of Reactor Vessel Head Determined Evidence of Boundary Leakage

Boroscopic inspection of the reactor head assembly during refuel outage A1R17 has determined that white powder residue observed at reactor head penetrations 41, 49, 61, 65, and 73 is evidence of past Reactor Coolant System pressure boundary leakage at one or more of these locations. This determination was made today at 0510 (CDT) after completion of boroscopic inspections and consultation with the reactor head vendor. These reactor head penetrations are control rod drive mechanism (CRDM) penetrations. The location of the identified leakage is suspected to be the omega seal welded threaded connection on one or more of these CRDM penetrations. Further inspections must be performed to confirm the exact leakage location. This condition will be repaired before U-1 returns to mode 4. The licensee has notified the NRC Resident Inspector.

  • * * RETRACTION ON 9/27/13 AT 1529 EDT FROM MATTHEW HENSON TO DONG PARK * * *

The purpose of this report is to retract ENS report #49353 (September 18, 2013). This report was made after boroscopic inspection of the Unit 1 reactor head assembly during refueling outage A1R17 determined that white powder residue observed at five Reactor Pressure Vessel (RPV) head penetrations was evidence of past Reactor Coolant System (RCS) pressure boundary leakage at one or more of these locations. At 1400 CDT on Wednesday, September 25, 2013, the Braidwood Nuclear Power Station (BNPS) concluded that the prior ENS notification could be retracted because the Plant Operations Review Committee had concluded that the white powder residue observed at five Unit 1 RPV head penetrations was not evidence of past RCS pressure boundary leakage. A detailed examination plan was implemented, which included a disassembly of the Digital Rod Position Indication (DRPI) and Control Rod Drive Mechanism (CRDM) coils for all five penetrations and a detailed visual examination using remote video equipments. The visual examinations used remote video equipments to inspect the lower and intermediate canopy seal weld areas for the five CRDMs. In addition, an examination of the upper canopy seal weld areas and a bare-metal inspection of the Reactor Pressure Vessel Head did not identify any evidence of boric acid leakage. Based on these inspections and a review of available photos from previous outages, BNPS concluded that the white residues were from incomplete cleaning in prior outages. The licensee has notified the NRC Resident Inspector. Notified R3DO (Dickson).

ENS 4922530 July 2013 19:32:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(3)(iv)(A), System Actuation
Reactor Scram Due to Turbine Generator Trip

Actuation of Reactor Protection System with reactor critical. Reactor Scram occurred at 1432 CDT on 7/30/2013 from 100% Power. The cause of the scram appears to be a Turbine Generator trip. 05-S-01-EP-2, 'Reactor Pressure Vessel Control,' 05-1-02-I-1, 'Reactor Scram Off Normal Event Procedure,' and 05-1-02-I-2, 'Turbine and Generator Trip Off Normal Event Procedure,' were entered to mitigate the transient. No Loss of Off-site Power occurred. No Emergency Core Cooling System or Diesel Generator initiation occurred. Reactor Core Isolation Cooling initiated and injected. The lowest reactor water level reached was -36 inches wide range (RCIC initiation set point is -41.6 inches wide range). Main Steam Isolation Valves remained open and no Safety Relief Valves actuated. Currently, Main Turbine Bypass valves are controlling reactor pressure to the Main Condenser and Condensate and Feedwater is controlling reactor water level in the normal band and removing decay heat. There are no challenges to Primary or Secondary Containment. The NRC Senior Resident Inspector was notified.

* * * UPDATE FROM CHRIS ROBINSON TO PETE SNYDER AT 1841 EDT ON 7/30/13 * * * 

The first out recorder indicated that RPS actuation signal was due to high reactor pressure as a result of the turbine control valves going shut. Notified R4DO (Farnholtz).

ENS 4912015 June 2013 19:22:0010 CFR 50.72(b)(3)(iv)(A), System ActuationDivision 1 and 2 Emergency Diesel Generators Power Buses After Momentary Offsite Power LossColumbia Generating Station is shutdown for a refueling outage and is currently in Mode 4. At 1222 PDT June 15, 2013, the 115 kV offsite power to the backup transformer relayed off and then came back on. Both Division 1 and Division 2 4.16 kV critical switchgear buses were powered from the backup transformer at the time of the loss of backup power. Upon detection of under voltage conditions, Emergency Diesel Generators 1 and 2 started and powered the Division 1 and Division 2 4.16 kV critical switchgear buses after approximately 5 seconds. The temporary loss of power to the Division 1 and Division 2 4.16 kV critical switchgear buses also resulted in the closure of containment isolation valves in the Reactor Water Cleanup System, Equipment Drain System and the Floor Drain System. Shutdown cooling had previously been secured in preparation of performing the reactor pressure vessel hydro test. Investigation into the cause of the temporary loss of the 115 kV offsite power is on-going. The Division 1 and Division 2 4.16 kV critical switchgear buses are currently being powered from the 230 kV offsite power through the startup transformer. There were no radiological releases as a result of this event." The licensee notified the NRC Resident Inspector.
ENS 4891611 April 2013 18:00:0010 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an AccidentDegraded Electrical Connections

On April 11, 2013, at 1300 hours, during the performance of On-Line Automatic Depressurization System (ADS) Blowdown Logic Testing, two poor wiring connections were identified (the electrical leads were not properly compressed at their termination point). The electrical leads are associated with the B and C ADS valves. Quad Cities has five ADS valves which can be used to depressurize the Reactor Pressure Vessel under accident conditions. While the solenoids of these valves were actuated successfully during the recent Unit 1 refueling outage (which ended on April 8, 2013), the less than optimum configuration could have prevented the valves from actuating under design basis conditions. The degraded wiring for both valves was restored at 1741 hours (CDT). Given the potential impact on the ADS depressurization function, this event is reportable under 50.72(b)(3)(v)(D) as an event or condition that could have prevented the fulfillment of a safety function. The licensee notified the NRC Resident Inspector.

  • * * RETRACTION ON 6/3/13 AT 1138 EDT FROM FRED SWIHART TO DONG PARK * * *

The purpose of this notification is to retract the ENS Report made on April 11, 2013, at 2110 EDT (ENS Report # 48916). Further evaluation performed by Quad Cities Station confirms the Unit 1, 3B and 3C Automatic Depressurization System (ADS) valves would have performed their safety functions when required. Based on this subsequent evaluation, ENS Report # 48916 is being retracted. Note: On April 11, 2013, at 1741 CDT the degraded wiring for the Unit 1, 3B and 3C ADS valves was repaired and both valves were returned to operable status. The licensee notified the NRC Resident Inspector. Notified R3DO (Orth).

ENS 4885327 March 2013 07:45:0010 CFR 50.72(b)(3)(ii)(A), Seriously DegradedReactor Pressure Boundary LeakageOn March 26, 2013, at 1635 (CDT), with Unit 1 shutdown for refueling, leakage was identified from the 2-inch reactor head vent line during a Reactor Pressure Vessel (RPV) pressure test. The leakage was approximately 20 drops per minute. The RPV pressure test was stopped and the reactor vessel depressurized to facilitate examination of the piping and associated flange connections. At 0245 hours on March 27, 2013, the leak was confirmed to be through-wall originating from a socket weld (i.e., pipe elbow). The cause and resolution are under evaluation. The condition is being reported under 50.72(b)(3)(ii)(A) given the defect was associated with the primary coolant system pressure boundary. The licensee notified the NRC Resident Inspector
ENS 4877220 February 2013 10:28:0010 CFR 50.72(b)(3)(ii)(A), Seriously DegradedDegraded Condition - Containment Penetration Fails Local Leak-Rate Testing

On February 20, 2013, at 0538 EST, local leak-rate testing (LLRT) of the 'A' feedwater check valves 2B21-F010A and 2B21-F077A revealed that neither valve would pressurize. Based on this information this line would not remain water filled post-LOCA and would result in the 'as found' minimum pathway leakage exceeding the limiting condition of operation (LCO) for Technical Specification 3.6.1.1. The cause for the LLRT failures will be determined and required corrective maintenance will be performed and valves successfully tested during the current refueling outage. The licensee notified the NRC Resident Inspector.

  • * * RETRACTION FROM KEN HUNTER TO VINCE KLCO ON 2/22/13 AT 1611 EST* * *

Subsequent investigation into the reported LLRT failure revealed that the initial LLRT performed on feedwater check valve 2B21-F010A was not considered an acceptable test, since that LLRT was not representative of the 'as found' condition of this check valve. The test volume for this valve had been slowly filled such that the check valve did not have the normal expected differential pressure across the valve disc to achieve normal check valve seating. After draining the test volume and refilling it by allowing the test volume to gravity fill from the reactor pressure vessel, the expected differential pressure across the valve disc occurred and seated the disc in such a way that it was more representative of the 'as found' condition for the check valve. An LLRT was then performed with a leakage of 50 accm (actual cubic centimeters per minute) against an acceptance criterion of 194 accm. No maintenance or operation of the check valve had occurred between the initial invalid test and the subsequent test performed with the disc in its 'as found' condition. An engineering evaluation was performed that documented the acceptability of using this means for establishing the test volume for feedwater check valves 2B21-F010A and 2B21-F010B for the 'A' and 'B' loops of feedwater, respectively. This engineering evaluation concluded that establishment of the required test volume in the manner described for primary containment penetration 9A satisfies the Hatch LLRT program requirements and that the leakage acceptance criterion for feedwater check valve 2B21-F010A in its 'as found' state was satisfied. The 2B21-F077A valve will be retested at a later date. Based on this information, the LLRT of this check valve in its 'as found' state was successful which actually resulted in successful minimum pathway leak rate test results for primary containment penetration 9A. These conclusive test results clearly indicated that the initial test results were incorrect and the 'as found' condition of this penetration isolation capability did not represent a significant degradation of a principal safety barrier as described in 10CFR50.72(b)(3)(ii)(A). For these reasons Notification # 48772 is being retracted. The licensee notified the NRC Resident Inspector. Notified the R2DO (McCoy).

ENS 4869023 November 2012 10:35:0010 CFR 50.73(a)(1), Submit an LERPrimary Containment Isolation Actuation Signal During SurveillanceThis 60-day telephone notification is being made in accordance with the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation of a general containment isolation signal affecting multiple Main Steam Isolation Valves (MSIVs). On November 23, 2012 at 0435 Central Standard Time, during performance of Surveillance Instruction 1-SI-3.3.1.A, ASME Section XI System Leakage Test of the Reactor Pressure Vessel and Associated Piping, as the Residual Heat Removal Loop II Shutdown Cooling was being placed in service, Group 1, Division II Primary Containment Isolation System (PCIS) logic groups A2 and B2 actuated resulting in an unanticipated Division II, Group 1 Complete Isolation and subsequent Inboard MSIV closure. The Outboard MSIVs had been previously tagged closed. Plant conditions which initiate Group 1 actuations are Reactor Vessel Low-Low-Low Water Level, Main Steamline Break, and Low Main Steamline Pressure at the Inlet to the Turbine. At the time of the event, these conditions did not exist; therefore, the actuation of the PCIS was invalid. The affected equipment responded as designed. This condition was the result of the reactor vessel water level being within two inches of the reactor head vent when Shutdown Cooling was placed into service, causing pressure perturbations. When these perturbations occurred, they gave an indication of low water level, causing the isolation and MSIV closure. There were no safety consequences or impact to the health and safety of the public as a result of this event. This event was entered into the (Browns Ferry Nuclear Plant) Corrective Action Program as Problem Evaluation Report 646607. The NRC Resident Inspector has been notified.
ENS 4868521 January 2013 01:50:0010 CFR 50.72(b)(2)(i), Tech Spec Required ShutdownTechnical Specification (Ts) Required Shutdown - Safety Relief Valve Declared InoperableOn Sunday, January 20, 2013, at 2050 hours, with the reactor at 100% core thermal power, the station entered a 24-hour action statement to initiate a controlled shutdown and be less than 104 psig reactor pressure due to suspected leakage across the first stage pilot of safety relief valve (SRV) RV-203-3B and subsequent declaration of the SRV inoperable due to criteria specified in Pilgrim plant procedure 2.2.23. As background, the pressure relief system includes four (4) SRVs and two (2) spring safety valves (SSVs). The SRVs discharge through their individual discharge piping, terminating below the minimum suppression pool (torus) water level. The four SRVs are installed on the main steam piping in containment between the reactor pressure vessel and the flow restrictors. While at full power, indication of a steam leak across the first stage pilot of RV-203-3B was determined in accordance with criteria specified in procedure 2.2.23. Specifically, the SRV is inoperable if the pilot stage thermocouple temperature is 35 degrees F below its baseline temperature (with a lower decrease at the 2nd stage thermocouple) and cannot be explained by a corresponding downpower. The safety relief valve was subsequently declared inoperable and the Limiting Condition for Operation (LCO) for Technical Specification (TS) 3.6.D was entered. Due to the valve being declared inoperable the station is required to be shutdown and reactor coolant pressure below 104 psig within 24 hours per TS 3.6.D.2. Currently a reactor shutdown is in progress to initiate safety relief valve repairs. This event has no impact on the health and/or safety of the public. The USNRC Senior Resident Inspector has been notified.
ENS 4860719 December 2012 22:31:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(3)(iv)(A), System Actuation
Automatic Reactor Scram Due to Low Reactor Pressure Vessel LevelAt approximately 17:31 hours on December 19, 2012, Susquehanna Steam Electric Station Unit Two reactor automatically scrammed on low RPV level (Level 3, +13 inches) while transitioning the 'A' reactor feed pump from discharge pressure mode to flow control mode. All control rods inserted and both reactor recirculation pumps tripped. Reactor water level lowered to approximately -29 inches causing Level 3 (+13 inches) isolations. An automatic trip of the reactor recirculation pumps occurred, but is not expected at this RPV level. There were no automatic emergency core cooling system initiations. No steam relief valves opened during the event. All safety systems operated as expected. The cause of the loss of feed water flow and trip of the reactor recirculation pumps is under investigation. This report is being made per 10CFR50.72(b)(2)(iv)(B) for a 4 hour report, and 10CFR50.72(b)(3)(iv)(A) for an 8 hour report. Decay heat is removed via steam to the main condenser using the bypass valves . On-site electrical power is in the normal configuration. The Unit 2 reactor is currently stable in Mode 3. Unit 1 was not affected and operates at 99% power. The licensee will inform the Commonwealth of Pennsylvania and make a press release. The NRC Resident Inspector was notified.
ENS 4859013 December 2012 21:30:0010 CFR 50.72(b)(3)(iv)(A), System Actuation
10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown
Technical Specification Required Shutdown Due to Primary Containment System Declared Inoperable

An increased usage of Nitrogen to maintain Primary Containment pressure within specification was noticed during steady state operation. Investigation into the extra Nitrogen usage revealed that Primary Containment Leakage was in excess of that allowed per Technical Specification 3.3.3.a. No action statement is provided for leakage in excess of Technical Specification 3.3.3.a; therefore in accordance with Technical Specification 3.0.1, the reactor shall be placed in an operational condition in which the specification is not applicable. This requires the plant to be shutdown and cooled down to less than 216 degrees F. Additionally, this is reportable as an event or condition that could have prevented fulfillment of a safety function of a system needed to control the release of radioactive material. The primary containment was declared inoperable at 1630 EST and a normal orderly plant shutdown was commenced at 1645 EST and will be less than 215 degrees F within 10 hours. Investigation of containment leakage is in progress. An update will be provided when the plant is in an operational condition in which Technical Specification 3.3.3.a is not applicable. The licensee has notified the NRC Resident Inspector. Licensee has notified the State of New York.

  • * * UPDATE AT 0011 EST ON 12/14/12 FROM CHRISTOPHER GRAPES TO BILL HUFFMAN * * *

As of 2333 EST on 12/13/2012, the reactor is below 215 degrees F, and containment is no longer required to be operable by Technical Specification 3.3.3. As part of the shutdown, a manual reactor scram was initiated as part of the pre-planned shutdown sequence and the High Pressure Coolant Injection (HPCI) System automatically initiated as expected. At Nine Mile Point Unit 1, a HPCI System actuation signal on low Reactor Pressure Vessel (RPV) level is normally received following a reactor scram, due to level shrink. HPCI is a flow control mode of the normal feedwater systems and is not an Emergency Core Cooling System. At 1913 EST, RPV level was restored above the HPCI system low level actuation set point and the HPCI system initiation signal was reset. Pressure control was established on the turbine bypass valves, the preferred system. No Electromatic Relief Valves actuated due to the scram. Nine Mile Point Unit 1 is currently in Cold Shutdown, with reactor water level and pressure maintained within normal bands. Decay heat is being removed via shutdown cooling (SDC). The offsite grid is stable with no grid restrictions or warnings in effect." The licensee has notified the NRC Resident Inspector and State authorities. Notified R1DO (Holody) and NRR EO (Lund).

ENS 484773 November 2012 12:23:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(3)(iv)(A), System Actuation
Automatic Scram on Low Reactor Water LevelOn November 3, 2012 at 0823 EDT, Nine Mile Point Unit 1 experienced an automatic reactor scram on low reactor water level. All control rods fully inserted and all plant systems responded per design following the scram. Prior to the automatic scram, an unexpected high Reactor Pressure Vessel (RPV) water level was experienced, followed by a turbine trip and subsequent lowering of RPV water level to the RPV low level scram set point. The cause of the water level transient is unknown. Following the automatic scram, the High Pressure Coolant Injection (HPCI) System automatically initiated as expected. HPCI is a flow control mode of the normal feedwater systems, and is not an Emergency Core Cooling System. At 0824 EDT, RPV level was restored above the HPCI System low level actuation set point and the HPCI System initiation signal was reset. Pressure control was established on the Turbine Bypass Valves, the preferred system. No Electromatic Relief Valves actuated due to this scram. Nine Mile Point Unit 1 is currently in Hot Shutdown, with reactor water level and pressure maintained within normal bands. Since the scram, there have been no anomalies observed with feedwater system operation. Decay heat is being removed via steam to the main condenser using the bypass valves. The offsite grid is stable with no grid restrictions or warnings in effect. The unit is currently implementing post scram recovery procedures. The licensee has notified the NRC Resident Inspector. Unit 2 was not affected during this event.
ENS 4845329 October 2012 04:00:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(3)(iv)(A), System Actuation
Rps Actuation While Critical Due to Generator Load RejectOn October 29, 2012 at 2100 EDT, Nine Mile Point Unit 1 experienced an automatic reactor scram due to a generator load reject. The cause of the load reject is currently under investigation. All control rods fully inserted and all plant systems responded per design following the scram. Following the automatic scram, the High Pressure Coolant Injection (HPCI) System automatically initiated as expected. At Nine Mile Point Unit 1, a HPCI System actuation signal on low Reactor Pressure Vessel (RPV) level is normally received following a reactor scram, due to level shrink. HPCI is a flow control mode of the normal feedwater systems, and is not an Emergency Core Cooling System. At 2101 EDT, RPV level was restored above the HPCI System low level actuation set point and the HPCI System initiation signal was reset. Pressure control was established on the Turbine Bypass Valves, the preferred system. Three Electromatic Relief Valves actuated due to this scram and re-closed automatically. Nine Mile Point Unit 1 is currently in Hot Shutdown, with reactor water level and pressure maintained within normal bands. Decay heat is being removed via steam to the main condenser using bypass valves. Both Reserve Station Transformers are in service and being supplied by their normal power sources. Both Emergency Diesel Generators are operable and in standby. The unit is currently implementing post scram recovery procedures. The licensee has notified the NRC Resident Inspector. Notified R1DO (Caruso).
ENS 4845229 October 2012 22:55:0010 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat
10 CFR 50.72(a)(1)(i), Emergency Class Declaration
10 CFR 50.72(b)(3)(iv)(A), System Actuation
Notice of Unusual Event Declared Due to High Intake Structure Water Level

At 1855 EDT on 10/29/2012, the licensee declared a Notice of Unusual Event (NOUE) per criteria HU4 for high water level in the station intake structure of greater than 4.5 feet. At the time of the notification, water level in the intake structure was approximate 4.8 feet and slowly rising. The cause of the increased water level was due to storm surge associated with Hurricane Sandy. No other station impacts were reported at the time. The licensee continues to monitor the intake levels and ocean tides. The licensee has notified the NRC Resident Inspector and the State of New Jersey.

  • * * ALERT UPDATE ON 10/29/2012 AT 2141 EDT FROM STEVE SERPE TO RYAN ALEXANDER * * *

At 2044 EDT on 10/29/2012, the licensee escalated its emergency declaration to an Alert per criteria HA4 for high water level in the station intake structure of greater than 6.0 feet. At the time of the notification, water level in the intake structure was approximately 6.6 feet. The site also experienced a loss of offsite power event concurrent with the additional water level increase. Both emergency diesel generators started and are supplying power to the emergency electrical busses. Shutdown cooling and spent fuel pool cooling have been restored. Reactor pressure vessel level is steady at 584.7 inches. Intake levels continues to rise slowly and the licensee is monitoring. The licensee has notified the NRC Resident Inspector and the State of New Jersey. Notified DHS SWO, FEMA Ops Center, USDA Ops Center, HHS Ops Center, DOE Ops Center, DHS NICC Watch Officer, EPA EOC, and NuclearSSA via e-mail.

  • * * UPDATE on 10/30/12 at 0414 EDT FROM GILBERT DEVRIES TO RYAN ALEXANDER * * *

The licensee updated this report with an 8-hour non-emergency notification of emergency diesel generator auto-actuation due to the actual loss of off-site power event (which occurred at 2018 EDT on 10/29/2012). This event caused a valid RPS actuation with automatic containment isolations that resulted in a temporary loss of shut-down cooling to the reactor. Shutdown cooling was subsequently restored with power provided by the emergency diesel generators. The licensee has notified the NRC Resident Inspector. Notified R1DO (Caruso).

  • * * UPDATE AT 0357 EDT ON 10/31/12 FROM GILBERT A. DeVRIES TO S. SANDIN * * *

Termination of Alert. The Oyster Creek Station has terminated the Alert that was declared at 2044 (EDT) on 10/29/12 due to Intake Structure high water level greater than 6.0 ft. MSL (EAL HA4). Intake water level has returned to normal and is now below the Unusual Event EAL threshold (4.5 ft. MSL) and continues to lower. The licensee informed state and local agencies and the NRC Resident Inspector. Notified Region I IRC (Clifford), NRR (Evans), and IRD (Marshall). Notified DHS SWO, FEMA Ops Center, USDA Ops Center, HHS Ops Center, DOE Ops Center, DHS NICC Watch Officer, EPA EOC, and NuclearSSA via e-mail.

ENS 4832320 September 2012 13:23:0010 CFR 50.72(b)(2)(iv)(B), RPS System Actuation
10 CFR 50.72(b)(3)(iv)(A), System Actuation
Automatic Scram and High Pressure Coolant Injection System InitiationOn September 20, 2012 at 0923 EDT, Nine Mile Point Unit 1 experienced an automatic reactor scram due to a turbine trip at power. The cause of the turbine trip is currently under investigation. All control rods fully inserted and all plant systems responded per design following the scram. Following the automatic scram, the High Pressure Coolant Injection (HPCI) System automatically initiated as expected. At Nine Mile Point Unit 1, a HPCI System actuation signal on low Reactor Pressure Vessel (RPV) level is normally received following a reactor scram, due to level shrink. HPCI is a flow control mode of the normal feedwater systems, and is not an Emergency Core Cooling System. At 0924 EDT, RPV level was restored above the HPCI System low level actuation set point and the HPCI System initiation signal was reset. Pressure control was established on the Turbine Bypass Valves, the preferred system. No Electromatic Relief Valves actuated due to this scram. Nine Mile Point Unit 1 is currently in Hot Shutdown, with reactor water level and pressure maintained within normal bands. Decay heat is being removed via steam to the main condenser using the bypass valves. The offsite grid is stable with no grid restrictions or warnings in effect. One 115kv off site power source (Line 4) is unavailable for planned maintenance at the James A Fitzpatrick Nuclear Power Plant. Both Reserve Station Transformers are in service and being supplied by the other 115kv offsite power source (Line 1). Both Emergency Diesel Generators are operable and in standby. The unit is currently implementing post scram recovery procedures. The licensee has notified the NRC Resident Inspector. Licensee has notified the state.
ENS 4793423 April 2012 06:00:0010 CFR 50.72(b)(3)(ii)(A), Seriously DegradedUltrasonic Examination Results in an Indication on the Reactor Pressure Vessel Head PenetrationOn April 23, 2012, during the Braidwood Station Unit 1 refueling outage, it was determined that the results of planned ultrasonic (UT) examinations performed on one penetration (Penetration No. 69) did not meet the applicable acceptance criteria, requiring repair prior to returning the reactor pressure vessel head to service. A portion of the indication was conservatively assumed to be within the J-groove weld. At the time of the examination, the Braidwood Station Unit 1 reactor pressure vessel head was classified as a low susceptibility head. The cause of the recordable indication is attributed to Primary Water Stress Corrosion Cracking. 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 pressure vessel head pressure boundary. All of the remaining penetrations have been examined during the current refueling outage. Repairs to Penetration No. 69 were completed prior to commencing startup. No other repairs were required. This is reportable pursuant to 10 CFR 50.72(b)(3)(ii)(A) since the as found indication did not meet the applicable acceptance criteria referenced in ASME Code Case N-729-1 to remain in-service without repair. The NRC Resident Inspector has been notified. As a result of a follow-up review, at 0600 CDT on 05/18/12, the licensee determined this was an 8 hour reportable event while Unit 1 was in Mode 4. The licensee did not determine this was a reportable event immediately after the UT was conducted on April 23, 2012. The unit is currently in Mode 3. Reactor Vessel Head Penetration No. 69 is a control rod penetration. Reactor Coolant Leakage test are satisfactory and there are no indications of boron buildup on the Reactor Vessel Head. Control rod testing has not yet been performed.
ENS 4788030 April 2012 23:01:0010 CFR 50.72(b)(3)(ii)(A), Seriously DegradedWeld Defect Indication Found in Residual Heat Removal System to Reactor Pressure Vessel NozzleGrand Gulf Nuclear Station is currently in Mode 4 (less than 200 degrees F) executing Refueling Outage 18 (RF-18) including in-service inspections. General Electric notified Entergy of a weld indication that was detected by automated ultrasonic testing. The indication is in the weld root area of N06B-KB Reactor Coolant System Pressure Boundary weld. The N06B nozzle connects Residual Heat Removal System 'C' to the Reactor Pressure Vessel. The dimension of the indication is approximately 0.9 inches in length, approximately 0.5 inches in depth and with no discernible width. Nominal wall thickness is 1.3 inches. The indication does not penetrate the entire thickness of the pipe wall and there is no leakage at the indication. There has been no release of radioactive material due to the indication. No systems were actuated due to this event. There are currently no other systems affected. The cause is under investigation and corrective action plans are being explored. The weld defect has been evaluated by Entergy Engineering and determined to meet the criteria for reporting identified in NUREG-1022: Welding or material defects in the primary coolant system that cannot be found acceptable under ASME Section XI, IWB-3600, 'Analytical Evaluation of Flaws,' or ASME Section XI, Table IWB-3410-1, 'Acceptable Standards'. The NRC Resident Inspector has been informed.
ENS 4786826 April 2012 14:12:0010 CFR 50.72(b)(3)(iv)(A), System ActuationValid Actuation of the Reactor Protection System During TestingAt 1012 EDT on April 26, 2012, during the Reactor Pressure Vessel Hydrostatic Test, a valid high pressure reactor scram occurred due to issues related to controlling pressure near rated values. This actuation of the Reactor Protection System was not part of the pre-planned testing sequence. All control rods were fully inserted at the time of the scram. This report is being made in accordance with 10CFR50.72 (b)(3)(iv)(A), 'Any event or condition that results in valid actuation of any of the systems listed except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation.' The reactor scram was reset after reactor pressure was lowered. The licensee has notified the NRC Resident Inspector.
ENS 478064 April 2012 22:16:0010 CFR 50.72(b)(3)(ii)(A), Seriously DegradedDegraded Condition Due to Identified Reactor Pressure Vessel Test LeakageOn April 4, 2012, at 1716 (CDT), with Unit 2 shutdown for refueling, leakage was identified from a 2-inch vessel nozzle during a Reactor Pressure Vessel (RPV) pressure test. The leakage amount was approximately one drop per second. The penetration (N-11B) is a reference leg used for reactor vessel instrumentation. The leakage originates from the area where the nozzle penetrates the vessel wall. The nozzle is welded on the inside of the vessel, so the actual attachment weld could not be examined at the time of this report. The RPV pressure test has been stopped and the reactor vessel depressurized. The cause and resolution are under evaluation. The condition is being reported under 50.72(b)(3)(ii)(A) given the defect was associated with the primary coolant system pressure boundary. The licensee notified the NRC Resident Inspector.
ENS 4755326 December 2011 17:50:0010 CFR 50.72(b)(2)(i), Tech Spec Required ShutdownTechnical Specification Required Shutdown - Safety Relief Valve Declared InoperableOn Monday, December 26, 2011, at 1250 hours, with the reactor at 100% core thermal power, the station entered a 24-hour action statement to initiate a controlled shutdown and be less than 104 psig reactor pressure due to suspected leakage across the first stage of safety relief valve (SRV) RV-203-3D and subsequent declaration of the SRV inoperable due to criteria specified in Pilgrim plant procedure 2.2.23. As background; the Pressure Relief System includes four (4) SRVs and two (2) spring safety valves (SSVs). The SRVs discharge through their individual discharge piping, terminating below the minimum suppression pool (torus) water level. The four SRVs and the two SSVs are installed on the Main Steam piping in containment between the reactor pressure vessel and the flow restrictors. While at full power, indication of a steam leak across the first stage pilot of RV-203-3D was determined in accordance with criteria specified in procedure 2.2.23. Specifically, the SRV is inoperable if the pilot stage thermocouple temperature is 35 degrees F below its baseline temperature (with a lower decrease at the 2nd stage thermocouple) and cannot he explained by a corresponding downpower. The safety relief valve was subsequently declared inoperable and the Limiting Condition for Operation (LCO) for Technical Specification (TS) 3.6.D was entered. Due to the valve being declared inoperable, the station is required to be shutdown and reactor coolant pressure below 104 prig within 24 hours per T.S. 3.6.D.2. Currently, preparations are being completed to conduct the reactor shutdown and to initiate safety relief valve repairs. This event had no impact on the health and/or safety of the public. The USNRC Senior Resident Inspector has been notified.