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| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 57136 | 23 May 2024 08:00:00 | 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Technical Specification Required Shutdown | The following information was provided by the licensee via email: At 0400 EDT on May 23, 2024, a technical specification required shutdown was initiated at Perry. Technical specification action 3.4.5 condition B (unidentified reactor coolant system leakage exceeds 5 gallons per minute) was entered on May 23, 2024 at 0000 with a required action to reduce leakage to within limits within 4 hours, due by 0400 on May 23, 2024. This required action was not completed within the completion time, therefore, a technical specification required shutdown was initiated, and this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(i). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The reactor coolant leakage was stable at approximately 6 gallons per minute. | Reactor Coolant System | |
| ENS 53000 | 4 October 2017 06:50:00 | 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | Perry Commenced Technical Specification Required Shutdown | On October 4, 2017, at 0250 hours (EDT), the Perry Nuclear Power Plant commenced a Technical Specification (TS) shutdown by lowering reactor power from 100 percent rated thermal power to 98 percent to comply with TS LCO 3.0.3. Reactor power was further reduced to 82 percent rated thermal power at 0430 hours (EDT). The plant had entered TS 3.0.3 at 0155 hours (EDT) upon loss of MCC (Motor Control Center), Switchgear, and Miscellaneous Electrical Equipment Areas HVAC System train A while train B was removed from service for maintenance. MCC switchgear ventilation train A was declared inoperable based on excessive belt noise and a dropped belt on MCC switchgear supply fan A. This also constitutes a loss of safety function. This event is being reported in accordance with 10 CFR 50.72(b)(2)(i) and 10 CFR 50.72(b)(3)(v)(D). The NRC Resident Inspector was notified.
Due to the loss of both trains of MCC, Switchgear, and Miscellaneous Electrical Equipment Areas HVAC, actions were taken in LCO 3.8.7 for AC and DC Distribution Systems, LCO 3.8.4 for DC Sources, LCO 3.8.1 for AC Sources, and the associated support systems, the High Pressure Core Spray system was also declared inoperable, which is a single train safety system and therefore, an additional loss of safety function. This event is being reported in accordance with 10 CFR 50.72(b)(3)(v)(B), 10 CFR 50.72(b)(3)(v)(C) and 10 CFR 50.72 (b)(3)(v)(D). At 0620 hours (EDT) the A train of MCC, Switchgear, and Miscellaneous Electrical Equipment Areas HVAC and High Pressure Core Spray was declared operable and LCO 3.0.3 was exited. The plant was restored to 100% (percent) power at 0804 (EDT). The NRC Resident Inspector was notified. Notified R3DO(Hills). | HVAC High Pressure Core Spray | 05000440/LER-2017-006 |
| ENS 51679 | 24 January 2016 02:22:00 | 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Ts Required Shutdown Due to Unidentified Leakage in Drywell | At 2100 hours (EST), on January 23, 2016, the Perry Nuclear Power Plant commenced a reactor shutdown due to unidentified leakage in the drywell. At 2122 hours, drywell unidentified leakage exceeded the Technical Specification 3.4.5.d limit of 'less than or equal to 2 gpm increase in unidentified LEAKAGE within the previous 24 hour period in Mode 1.' The unidentified leakage increased to approximately 3.8 gpm at 2122 hours. Current unidentified leakage is 3.02 gpm. Technical Specification 3.4.5 actions allow 4 hours to reduce the leakage within limits or be in Mode 3 within 12 hours and Mode 4 within 36 hours. The plant is required to be in Mode 3 by 1322 hours on January 24, 2016 and Mode 4 by 1322 hours on January 25, 2016. A drywell entry will be made in Mode 3 to identify the leak source. This notification is being made due to an expected inability to restore the leakage within limits prior to exceeding the LCO action time. Follow up question from NRC: Event times do not match (2100 versus 2122) - explained downpower was commenced at 2100 with leakage less than TS limit. When Reactor Core flow was reduced, un-identified leakage increased above the TS limit. The Licensee has notified the NRC Resident Inspector.
At 1007 hours, on January 24, 2016 with the plant at 8% power during a feedwater shift to place the motor feed pump in service, reactor level rose to the level 8 scram set point and the Reactor Protection System (RPS) initiated, scramming the reactor. During the scram, all rods fully inserted into the core. Decay heat is being removed via turbine bypass valves to the main condenser. Reactor level control is currently being maintained via feedwater. The plant is stable with cool down and depressurization to Mode 4 to follow. The cause of the rise in feedwater level is under investigation. This notification is being made under 50.72(b)(2)(iv)(B) for a RPS initiation while critical. All safety shutdown systems are available. The electric plant is in its normal shutdown alignment being supplied by offsite power. The licensee has notified the NRC Resident Inspector. Notified R3DO (Cameron). NRR (Morris) and IRD (Gott) were notified via email.
Following a shutdown required by plant Technical Specifications a small leak was identified coming from the Reactor Recirculation Loop A Pump Discharge Valve vent line. The Recirculation Loop is part of the reactor coolant system making this reportable under 50.72(b)(3)(ii)(A) as a degraded condition. It was subsequently determined to require a plant cool down in accordance with Technical Specification 3.4.5, Action C which requires the plant to be in MODE 4 within 36 hours. Technical Specification 3.4.5 was previously entered for increased unidentified leakage in the drywell. The plant is required to be in Mode 4 by 1322 hours on January 25, 2016. The licensee has notified the NRC Resident Inspector. Notified R3DO (Cameron). NRR (Morris) and IRD (Gott) were notified via email. | Reactor Coolant System Feedwater Reactor Protection System Main Condenser | 05000440/LER-2016-001 |
| ENS 49804 | 7 February 2014 11:00:00 | 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Plant Shutdown Required by Technical Specifications Due to Containment Isolation Valve Over Leak Rate Limit | This event is being reported in accordance with 10CFR 50.72(b)(2)(i), 'Initiation of a Shutdown Required by Technical Specifications.' At 2043 hours (EST) on February 06, 2014, the Perry Nuclear Power Plant entered Technical Specification 3.6.1.3 Primary Containment Isolation Valves (PCIVs), action C.1, due to leakage identified during local leak rate testing of the containment penetration for the Containment and Drywell Purge system. Leakage was identified on the outboard containment isolation valve resulting in the plant exceeding the limit for secondary containment bypass leakage. The Containment and Drywell Purge system penetration is normally isolated and remains isolated in accordance with Technical Specifications. Action C.1 requires restoration of the leakage rate within four hours. At 0043 hours on February 7, 2014, the plant entered Technical Specification 3.6.1.3, 'Primary Containment Isolation Valves (PCIVs)', action E as the leakage rate was not restored. Action E requires the plant be in Mode 3 in 12 hours and Mode 4 in 36 hours. At 0600 hours on February 07, 2014, the Perry Nuclear Power Plant initiated a shutdown in accordance with Technical Specification 3.6.1.3, action E. Repairs to restore the penetration leakage to within allowable limits are in progress. The NRC Resident Inspector has been notified.
At 0943 hours (EST) the reactor shutdown to comply with Technical Specification 3.6.1.3 action E was terminated (with the reactor at 42% power). A blind flange was installed downstream of the outboard containment isolation valve. Local leak rate testing of the containment penetration for the Containment and Drywell Purge system verified that leakage was within the limits for secondary containment bypass leakage. The NRC Resident Inspector has been notified. The licensee has commenced increasing reactor power. Notified R3DO (Orlikowski) | Secondary containment Primary containment | |
| ENS 49121 | 16 June 2013 04:00:00 | 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | Technical Specification Shutdown Due to Small Reactor Coolant Leak on a Recirculation Flow Control Valve Vent Line | This event is being reported in accordance with 10 CFR 50.72(b)(2)(i) and 50.72(b)(3)(ii)(A). On June 16, 2013 at 0200 EDT, the Perry Nuclear Power Plant commenced a controlled plant shutdown. The shutdown was due to a small leak through the base of a vent line on the 'B' Reactor Recirculation Flow Control Valve. On June 15, 2013 at 2250 EDT, the leak was identified and was subsequently determined to require a plant shutdown in accordance with Technical Specification 3.4.5, Action (C) which requires the plant to be in Mode 3 within 12 hours. The NRC Resident Inspector has been notified." The licensee will also be notifying state and local authorities. The licensee had come down in power to make a drywell entry and investigate drywell leakage indications. Steam was observed to be coming from a vent line that comes off the top of the recirc flow control valve. The licensee was unable to characterize the leak rate other than a small leak. The licensee stated that the steam appeared be coming from a weld location where the vent line comes out of the flow control valve which would classify it as pressure boundary leakage. | 05000440/LER-2013-003 | |
| ENS 47312 | 2 October 2011 05:00:00 | 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Shutdown Required by Technical Specifications Due to Transformer Fault | This event is being reported in accordance with 10CFR50.72(b)(2)(i). On October 2, 2011, at approximately 0100 hours (EDT), the Perry Nuclear Power Plant commenced a controlled plant shutdown. The shutdown was due to the anticipated investigation and expected repair time of the Unit 1 startup transformer exceeding the Technical Specification (TS) Required Action completion time. On September 29, 2011, at 0529 hours (EDT) the Unit 1 startup transformer failed due to an internal fault, which required entry into TS 3.8.1 Action A.2 for one required offsite circuit inoperable. The determination has been made that the required action, which is to restore the required offsite circuit to OPERABLE status, cannot be met by the required completion time and a plant shutdown is being initiated. The NRC Resident Inspector has been notified. The licensee expects to have the Unit offline between 1300-1400 hours (EDT) and plans to issue a press release. | 05000440/LER-2011-002 | |
| ENS 45918 | 12 May 2010 03:18:00 | 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Manual Reactor Scram Due to Loss of Control Rod Drive Charging Water Header Pumps | On May 11, 2010, at approximately 2318 hours, a manual Reactor Protection System (RPS) actuation was initiated as required by Technical Specification (TS) Limiting Condition for Operation (LCO) 3.1.5 'Control Rod Scram Accumulators.' Control Rod Drive (CRD) charging water header pressure was less than 1520 psig (i.e., no CRD pumps operating) and there were multiple accumulator faults on withdrawn control rods. At the time of the event, the plant was in Mode 1 at 100% power. All control rods are inserted into the core and the plant is currently stable, in Mode 3 (Hot Shutdown) with reactor pressure at approximately 930 psig. No Emergency Core Cooling Systems were required or utilized to respond to the event and there were no other 10 CFR 50.72 reportable actuations. Reactor coolant level is being maintained in its normal band by the feedwater system and decay heat is being removed by the condenser. The plant is in a normal electrical line-up with all three Emergency Diesel Generators operable and available if needed. The cause of the event initiator, an invalid Division 2 Loss of Coolant Accident (LOCA), i.e., High Drywell Pressure/Low Reactor Vessel Water Level, signal, is currently under investigation. Prior to the manual RPS Actuation, the invalid LOCA signal resulted in invalid actuations of Division 2 equipment and systems including, the Division 2 Emergency Diesel Generator (EDG), (which started but did not load onto the bus), Low Pressure Coolant Injection B and C subsystems (which started the pumps but did not inject into the vessel), discharge of the Suppression Pool Makeup subsystem B into the suppression pool, startup of the Control Room Emergency Recirculation subsystem B, and isolation of Group 2B Containment isolation valves which included the Nuclear Closed Cooling System Containment Return Isolation valve that was not already closed. The affected equipment is being restored in accordance with plant procedure. The NRC Resident Inspector has been notified. The licensee experienced an instrumentation rack loss of power which appears to have resulted in the inadvertent Division 2 initiation. The initiator of this event also and led to a loss of power to both control rod drive charging water header pumps resulting in charging water header pressure less than required and related accumulator faults which placed the licensee in a technical specification required shutdown condition. The action statement allows only 20 minutes to restore the condition which was insufficient time for the licensee to correct the condition so a manual scram was initiated from 100% power. The scram was characterized as an uncomplicated scram and all system responses (not related to the initial instrument fault) functioned as required. | Feedwater Reactor Protection System Emergency Diesel Generator Emergency Core Cooling System Control Rod | 05000440/LER-2010-003 |
| ENS 45434 | 15 October 2009 16:25:00 | 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Unit Commenced Shutdown Due to Inoperable Division 2 Emergency Service Water System | This event is being reported in accordance with 10CFR50.72(b)(2)(i). On October 15, 2009, at approximately 1225 hours, the Perry Nuclear Power Plant commenced a Technical Specification required plant shutdown. On October 14, 2009, At 1747 hours, the Division 2 Emergency Service Water (ESW) system was declared inoperable and unavailable for planned work. The plant entered Technical Specification (TS) 3.7.1 Action A for one inoperable ESW Division. Other supported TSs were also entered (TS 3.8.1 for the Division 2 diesel generator, TS 3.6.1.7 for Containment Spray 'B', TS 3.6.2.3 for Suppression Pool Cooling 'B', TS 3.7.10 for Emergency Closed Cooling 'B', TS 3.5.1 for LPCI 'B' & 'C', among others). On October 15, 2009, at 0601 hours, the ESW 'B' pump was started for a planned pump run. At 0718 hours, the ESW 'B' pump tripped for unknown reasons. The determination was made to commence a controlled plant shutdown and power reduction commenced at 1225 hours. This decision was based on the anticipated investigation and repair time of ESW 'B' pump exceeding the TS 3.7.1 Action A 72 hour LCO completion time, and therefore, Action B requires the plant to be in MODE 3 within 12 hours and in MODE 4 in 36 hours. The TS 3.7.1 Action A 72 hour LCO completion time coincides with October 17, 2009, at 1747 hours. Currently, the plant is expected to be in MODE 3 at approximately 2300 hours on October 15, 2009. The NRC Resident Inspector has been notified. The State and Counties will also be notified. | Service water Containment Spray | 05000440/LER-2009-003 |
| ENS 41657 | 2 May 2005 10:11:00 | 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Technical Specification Required Shutdown - Reactor Vessel Level Instrumentation | On 5/1/05 at 19:16, the plant entered MODE 2 and began a reactor startup. After withdrawing control rods, but prior to criticality, perturbations were noticed on reactor vessel level indications and control rod withdrawal was halted. At 22:32 control rods were inserted in reverse order to maintain the reactor subcritical. At that time, level instrumentation associated with the 'A' level reference leg was declared inoperable. All control rods were inserted at 23:02 in Mode 2. At 23:32 on 5/1/05 a 12 hour shutdown statement was entered due to the inoperable level instrumentation. Efforts were underway to troubleshoot and restore the level Instrumentation. On 5/2/05 at 06:11 the reactor mode switch was placed in shutdown - level instrumentation will not be restored within the time allowed by Technical Specifications. Instrument fill and vent procedures are being implemented at this time. The plant expects to enter Mode 2 later today. Technical specification 3.3.6.1 requires restoration within one hour, shutdown within 12 hours. This reference leg level affects both the wide and narrow range level instruments and feed into the Reactor Protective System, Emergency Core Cooling System Instrumentation, and Isolation Instrumentation systems. The licensee notified the NRC Resident Inspector.
Update to Event Notification (EN 41657) Retraction: A 4-hour notification was made on May 2, 2005, in accordance with 10CFR50.72(b)(2)(i), for a shutdown required by Technical Specifications. The report was made due to inserting all withdrawn control rods during a startup, prior to criticality, for Technical Specification 3.3.6.1 required actions. Technical Specification 3.3.6.1 was entered as a result of level perturbations determined to have been caused by reference leg keep-fill system operation when the reactor pressure vessel (RPV) was under vacuum conditions with minor component compression fitting leaks. Actions were taken to fix the minor leaks in the reference leg keep-fill panel. Additionally, the reference leg keep-fill system was removed from service until the RPV was pressurized. It was subsequently determined that since the reactor had not yet been taken critical, the reactor was in a shutdown condition. Per NUREG-1022, rev 2, section 3.2.1 'Plant Shutdown Required by Technical Specifications,' the 'initiation of any nuclear plant shutdown' does not include mode changes required by TS if initiated after the plant is already in a shutdown condition. Since the plant remained in a shutdown condition, this issue is not reportable. Since the condition is not reportable. EN 41657 is retracted. The licensee notified the NRC Resident Inspector. The R3DO (Burgess) has been notified. | Reactor Pressure Vessel Emergency Core Cooling System Control Rod | |
| ENS 41085 | 2 October 2004 19:00:00 | 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Reactor Power Being Reduced Due to Entering Ts 3.0.3 Because of Inopeable Recirc Vent System | At 1500 hours the plant commenced reactor shutdown from 100% power for entering T.S. 3.0.3 due to both trains of the Emergency Recirc Vent System being declared inoperable. The reactor will be in mode 2 by 2000 hours, mode 3 by 0200 hours on 10/03 and mode 4 by 0200 hours on 10/04. If the problem is corrected, they will terminate the shutdown. The NRC Resident Inspector was notified. HOO Note: see event 41084
Update to (Event) Notifications 41084 and 41085: At 1840 (EDT) on 10/02/04 it was determined that the apparent slow response times of the Control Room Emergency Recirculation (CRER) dampers was due to a malfunctioning relay in the initiation circuit, not due to failure of the dampers. The LCO actions associated with the CRER system were exited and the actions associated with the initiation instrument were entered. Therefore the plant is no longer required to shutdown per T.S. 3.0.3. The plant shutdown has been terminated. Plant power will be returned to 100%. The licensee has notified the NRC resident Inspector. Notified R3DO (Thomas Kozak).
At 1300 on 10/02/04, results of a surveillance indicated that dampers in both trains of the Control Room Emergency Recirculation System (CRERS) were slower than allowed by Technical Specifications (TS) requiring both trains of the CRERS to be declared inoperable. With both trains inoperable, Technical Specification 3.0.3 was entered which required a plant shutdown. The shutdown was commenced at 1500. This condition was reported as required in Event Notification 41085. Additionally, with both CRERS trains inoperable, this condition was determined to be reportable as a loss of safety function (accident mitigation) and was reported as required in Event Notification 41084. Subsequently, it was determined that the failure was the result of a defective time delay relay in the radiation monitor initiation circuit. Other inputs that would have caused the dampers to reposition in an accident were not impacted. The appropriate TS (3.3.7.1), for the radiation monitor, was entered and TS 3.0.3 was exited. The significant actions required by this TS were to restore the function within 7 days or place the system in emergency recirculation. It did not require entry into an action to shutdown. When this condition was identified, TS 3.0.3 was exited, the shutdown was terminated, and the plant was restored to full power. Since a TS required shutdown was not required, Event Notification 41085 is being retracted. The licensee has notified the NRC Resident Inspector. NRC R3DO(Gardner) has been notified. | ||
| ENS 40767 | 21 May 2004 20:00:00 | 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Technical Specification Shutdown | Emergency Service Water "A" (ESW) Pump failure results in inoperability of all Div 1 ECCS systems. The plant entered the Limiting Condition for Operation for the ESW inoperability at 0150 on 05/21/04. The action times for Tech Spec 3.7.1 are as follows: restore ESW to operable status within 72 hours, if this cannot be accomplished be in Mode 3 (Hot Shutdown) in the following 12 hours and Mode 4 (Cold Shutdown) in 36 hours. Reactor power was reduced at 1600 to begin the shutdown process. Division 2 and 3 ECCS are fully operable. The NRC Resident Inspector was notified of this event by the licensee. | Service water | 05000440/LER-2004-001 |