Semantic search
Entered date | Site | Region | Reactor type | Event description | |
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ENS 55046 | 23 December 2020 12:28:00 | LaSalle | NRC Region 3 | GE-5 | At 0653 CST on 12/23/20, it was discovered the single train of high pressure core spray was inoperable. Due to this inoperability, the system was in a condition that could have prevented the fulfillment of a safety function; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v). All other emergency core cooling systems were operable during this time. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The high pressure core spray is inoperable because the water lake pump tripped. This inoperability puts the licensee in a 14-day limiting condition for operability. |
ENS 54693 | 4 May 2020 23:40:00 | LaSalle | NRC Region 3 | This report is being made pursuant to 10 CFR 50.72(b)(3)(v)(D), Event or Condition that could have prevented fulfillment of a Safety Function needed to mitigate the Consequences of an Accident. A through wall leak was found on piping connected to the Division 3 Diesel Generator (DG) Cooling Water Strainer. This condition has been evaluated and the Division 3 DG Cooling Water System has been declared inoperable. The Division 3 DG Cooling Water System is a support system for the Division 3 Emergency DG and the High Pressure Core Spray System (HPCS). The NRC Resident Inspector has been notified.
This update retracts Event Notification #54693, which reported a condition that could have potentially prevented fulfillment of a safety function needed to mitigate the consequences of an accident. An evaluation of the flaw on the piping connected to the Unit 2 Division 3 Diesel Generator (DG) Cooling Water strainer concluded that the system would have remained operable. The High Pressure Core Spray system, supported by the operable DG Cooling Water system, remained operable and capable of performing its safety function. The NRC Resident Inspector has been notified. Notified R3DO (Stone). | |
ENS 54384 | 12 November 2019 18:23:00 | LaSalle | NRC Region 3 | This report is being made pursuant to 10CFR50.72(b)(2)(xi), "News Release or Notification of Other Government Agency". The Main Control Room received a report from on-site Maintenance personnel performing diving activities at the lake screen house that communications with a diver had been lost. Onsite and offsite emergency responders were dispatched. The diver was removed from the water but was unresponsive. At 1601 (CST), the LaSalle County Station Operating Department was notified by emergency responders on-site that the individual was deceased. The Grundy County Sheriff, LaSalle County Sheriff, Seneca Emergency Services, and NRC Senior Resident Inspector have been notified. A press release is planned | |
ENS 53903 | 1 March 2019 04:03:00 | LaSalle | NRC Region 3 | On February 28, 2019, at 2217 CST, LaSalle Unit 2 experienced a trip of the 241Y Safety Related Bus during surveillance testing resulting in a valid undervoltage actuation signal to the Common Emergency Diesel Generator ('O' EDG), causing it to start and load to Bus 241Y. The purpose of the surveillance testing was to demonstrate the operability of the breakers necessary to provide the second off site source to Unit 2. This event is reportable in accordance with 10 CFR 50.72(b)(3)(iv)(A), as an event that results in a valid actuation of the emergency AC electrical power system. In addition to the 241Y bus trip and 'O' EDG actuation signal, the following plant responses occurred as designed due to the momentary loss of this AC Bus: "A" RPS de-energized due to the loss of the 2A Reactor Protection System Motor-Generator Set, and the running Unit 2 Fuel Pool Cooling pump tripped. The Non-Safety Related Bus 241X de-energized resulting in a trip of the Unit 2 Station Air Compressor. All systems have been restored and troubleshooting is currently in progress. Unit 1 remained in MODE 1 during this event. The NRC Senior Resident Inspector has been notified. | |
ENS 53576 | 31 August 2018 23:26:00 | LaSalle | NRC Region 3 | This notification is being provided in accordance with 10 CFR 50.72(b)(2)(iv)(B). On August 31, 2018 at 2105 CDT, Unit 2 Reactor Manual Scram signal was inserted due to Main Condenser vacuum degrading. The turbine was tripped following the scram. Main Condenser vacuum is at 6 inches of backpressure slowly improving following the scram and turbine trip. During the scram, one Control Rod (30-31) did not fully insert. Control Rod 30-31 has been manually inserted to position 00 with the first position identified as position 24. Plant is in a stable condition with reactor pressure being maintained by the Turbine Bypass valves. Reactor water level is being controlled with feedwater. Investigation into the cause of the elevated condenser in leakage is in progress. The Senior NRC Resident has been notified. | |
ENS 53276 | 22 March 2018 07:07:00 | LaSalle | NRC Region 3 | GE-5 | This notification is being provided in accordance with 10CFR50.72(b)(2)(i), Plant Shutdown required by Technical Specifications, and 10 CFR 50.72(b)(3)(ii)A, Degraded or Unanalyzed Condition. At 0300 CDT on 3/22/18, on LaSalle Unit 1, a through-wall (welded joint) leak was identified on a 3/4 inch vent line off of the bonnet of the 1B33-F067B, 1B Reactor Recirculation Pump Discharge Valve. This condition qualifies as pressure boundary leakage, which requires entry into Technical Specification 3.4.5, Reactor Coolant System Operational Leakage, Required Action C, to be in Mode 3, Hot Shutdown, by 1500 on 3/22/18 and Mode 4, Cold Shutdown, by 1500 on 3/23/18. This leakage is significantly less than 10 gallons per minute and therefore, does not meet the threshold for entry into the Emergency Action Plan. At the time of discovery, Unit 1 was in Mode 1 - Run. Shutdown began at 0500 CDT and the estimated completion to cold shutdown is 2000 CDT. All necessary shutdown equipment is available. There is no impact to Unit 2. NRC Resident Inspector was notified. |
ENS 53219 | 17 February 2018 10:29:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made in accordance with 10 CFR 50.72(b)(3)(v)(D) for an event or condition that could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident. While troubleshooting an issue with the Unit 1B Diesel Generator Oil Circulating pump, damage of a bus bar was identified at the breaker that supplies the Unit 1B Diesel Generator Auxiliaries. One of the loads fed from this breaker is the Division 3 DC Battery Charger. It has been determined that the degradation of the bus bar may have prevented the Division 3 DC Battery Charger from performing its function which could have prevented the High Pressure Core Spray System (HPCS) from performing its design safety function. Since HPCS is a single train safety system, it has been determined that this failure could potentially affect the safety function of this system, and is reportable as an 8 hour notification. The NRC Resident Inspector has been notified. |
ENS 53213 | 15 February 2018 13:39:00 | LaSalle | NRC Region 3 | GE-5 | On February 15, 2018, during evaluation of protection for Technical Specifications (TS) equipment from the damaging effects of tornado generated missiles, LaSalle Station identified a non-conforming condition in the plant design such that specific TS equipment is considered to not be adequately protected from tornado generated missiles. Tornado generated missiles could strike the components supporting the operation of Control Room (VC) and Auxiliary Electric Room (VE) ventilation. This could result in inoperable VC/VE systems, which provide a protected environment for occupants to control the unit following an uncontrolled release of radioactivity, hazardous chemicals, or smoke if a tornado were to occur. This condition is reportable in accordance with 10 CFR 50.72(b)(3)(ii)(B) as a condition that results in the nuclear power plant being in an unanalyzed condition that significantly degrades plant safety and 10 CFR 50.72(b)(3)(v)(D) as 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 mitigate the consequences of an accident. This condition is being addressed in accordance with NRC enforcement guidance provided in Enforcement Guidance Memorandum (EGM) 15-002, Revision 1, 'Enforcement Discretion for Tornado-Generated Missile Protection Noncompliance,' and DSS-ISG-2016-01, Revision 1, 'Clarification of Licensee Actions in Receipt of Enforcement Discretion' per Enforcement Guidance Memorandum EGM 15-002, 'Enforcement Discretion for Tornado Generated Missile Protection Noncompliance.' Compensatory measures have been implemented in accordance with these documents. The NRC Resident Inspector has been informed of this notification. |
ENS 53083 | 21 November 2017 14:22:00 | LaSalle | NRC Region 3 | GE-5 | On October 6, 2017 at 0910 CDT hours, with Unit 1 in Mode 1 (Power Operation), the 1A Diesel Generator Cooling Water Pump (DGCWP) automatically started. The cause was the misoperation of the 1B/C RHR (Residual Heat Removal) Room Cooler Fan (1VY03C) control switch, which was placed in the start position instead of the intended pull-to-lock position. The start of the 1VY03C fan resulted in the automatic actuation of the 1A DGCWP. This system actuation is reportable in accordance with 10CFR50.73(a)(2)(iv)(A). The invalid actuation was not part of a pre-planned sequence during testing or reactor operation. The 1A DGCWP, an emergency service water system that does not normally run and that serves as an ultimate heat sink, responded satisfactorily. This call is being made in accordance with 10CFR50.73(a)(1), which states that in the case of an invalid actuation reported under 10CFR50.73(a)(2)(iv), other than an actuation of the reactor protection system when the reactor is critical, the licensee may provide a telephone notification to the NRC Operations Center within 60 days after discovery of the event instead of submitting a written Licensee Event Report. The licensee notified the NRC Resident Inspector. |
ENS 52821 | 23 June 2017 01:00:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10 CFR 50.72(b)(3)(v)(D) for an event or condition that could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident. The Unit 1 Low Pressure Core Spray (LPCS) Pump Injection System was declared inoperable at 2043 (CDT) due to a loss of corner room area cooling and loss of motor cooling. The common diesel generator cooling water pump received an auto trip signal while being secured. The LPCS pump remained in standby during the event. This condition prevents LPCS, a single train safety system, from performing its design function. This is a reportable condition as an 8 hour ENS notification. The required action of Technical Specifications (TS) 3.5.1, 'ECCS - Operating,' was entered on June 22, 2017 at 2043 CDT when the condition was identified and the LPCS system was determined to be inoperable. Investigation into the cause of the condition is in progress. The Low Pressure Core Spray (LPCS) Pump Injection System was declared operable, and the TS LCO was exited at 2112 CDT.
Update to previous ENS notification at 0100 EDT on 6/23/17. The last statement was revised to say the Low Pressure Core Spray System remains Inoperable. The Low Pressure Core Spray (LPCS) Injection System remains inoperable. The licensee notified the NRC Resident Inspector. Notified R3DO (Pelke). |
ENS 52761 | 17 May 2017 12:29:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10 CFR 50.72(b)(3)(v)(D) for an event or condition that could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident. The Low Pressure Core Spray (LPCS) Pump Injection HI Flow alarm was received at 09:08 CDT on May 17, 2017, at which point the minimum flow valve was observed to go closed. The LPCS pump remained in standby during the event. To prevent damage if the pump were to auto start, the control switch for the LPCS pump was placed in pull to lock. This condition prevents LPCS, a single train safety system, from performing its design function. This is a reportable condition as an 8 hour ENS notification. The required action of Technical Specifications (TS) 3.5.1, 'ECCS - Operating,' was entered on May 17, 2017 at 09:08 CDT when the condition was identified and the LPCS system was determined to be inoperable. Investigation into the cause of the condition is in progress. There were no related work activities in progress at the time the condition was identified. The licensee notified the NRC Resident Inspector. |
ENS 52564 | 18 February 2017 02:58:00 | LaSalle | NRC Region 3 | GE-5 | This notification is being provided in accordance with 10CFR 50.72(b)(2)(iv)(B). On February 17, 2017 at 2353 CST, Unit 1 Reactor Automatic Scram signal was received due to Turbine Control Valves Fast Closure. The turbine trip was due to receipt of Level 8 Trip due to a failure of the Feedwater Regulating Valve to Full open. Plant is in a stable condition with reactor pressure being maintained by the Turbine Bypass valves. Reactor water level is being controlled with Feedwater thru the Low Flow Feedwater Regulating Valve. Further investigation into the cause of the event is in progress. All control rods fully inserted, and decay heat is being removed via steam to the main condenser using bypass valves. The licensee has notified the NRC Resident Inspector.
Upon further review of the event data, it was determined that the Nuclear Station Operator (NSO) had initiated a manual scram, which was followed by a Turbine Control Valve (TCV) fast closure automatic scram when the turbine tripped. The licensee has notified the NRC Resident Inspector. Notified R3DO (Jeffers). |
ENS 52556 | 16 February 2017 13:54:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made in accordance with 10 CFR 50.72(b)(3)(v)(C), for an event or condition that could have prevented fulfillment of a safety function needed to control the release of radioactive material and 10 CFR 50.72(b)(3)(v)(D) for an event or condition that could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident. An employee entered a secondary containment airlock and identified that both doors of the airlock opened simultaneously when the door on the reactor building side was opened. The employee immediately secured both doors in the airlock and notified the Main Control Room Supervisor. Both doors in the airlock were open for approximately 5 seconds. With both doors open, Technical Specifications (TS) Surveillance Requirement (SR) 3.6.4.1.2 was not met. This rendered secondary containment inoperable in accordance with TS 3.6.4.1. Reactor Building differential pressure, as observed in the Main Control Room, has remained more negative than -0.25 inches of vacuum water gauge at all times. Initial investigation determined that the interlock for the doors was malfunctioning. Administrative controls have been put in place to ensure the doors remain closed pending repairs to the interlock. The licensee informed the NRC Resident Inspector. |
ENS 52547 | 14 February 2017 02:40:00 | LaSalle | NRC Region 3 | GE-5 | This notification is being provided in accordance with 10 CFR 50.72(b)(2)(iv)(B). On February 13, 2017 at 2309 CST, a Unit 1 Reactor Automatic Scram signal was received due to Turbine Control Valve Fast Closure. The turbine trip was due to the main generator trip on Differential Current. The 'U' safety relief valve actuated in the relief mode on the turbine trip, and has subsequently reset with tailpipe temperature returning to normal. The plant is in a stable condition with reactor pressure being maintained by the Turbine Bypass valves. Reactor water level is being controlled with feedwater. Investigation into the cause of the event is in progress. All control rods fully inserted on the scram. Unit 1 is in a normal shutdown electric plant alignment. Unit 2 was not affected. The licensee notified the NRC Resident Inspector. |
ENS 52519 | 30 January 2017 23:34:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10 CFR 50.72(b)(3)(v)(D), event or condition that could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident. During routine surveillance testing of the Unit 2 Division 3 Emergency Diesel Generator (LOS-DG-M3), the Cooling Water Strainer Backwash Valve, 2E22-F319, was identified to have stem/disk separation and could not be opened. This condition has been evaluated and the Division 3 Diesel Generator Cooling Water system has been declared inoperable. The Division 3 Diesel Generator Cooling Water system is a support system for the Division 3 Emergency Diesel Generator and the High Pressure Core Spray System (HPCS). The required actions of Technical Specification (TS) 3.5.1 were entered on 1/30/17 at 1908 CST when the HPCS system was determined to be inoperable. This condition could have prevented the HPCS, a single train safety system, from performing its design function. The licensee has notified the NRC Resident Inspector. |
ENS 52505 | 23 January 2017 10:34:00 | LaSalle | NRC Region 3 | GE-5 | This notification is being provided pursuant with 10 CFR 50.72 (b)(2)(iv)(B). (On January 23, 2017) at 0806 (CST), Unit 2 Manual Scram was inserted due to a Stator Water Cooling runback signal and a Turbine Bypass Valve opening. The Plant is stable, reactor pressure is being maintained with Bypass valves. Reactor water level is being controlled with feedwater. Investigation into the cause of the event is in progress. All control rods fully inserted. The licensee has notified the NRC Resident Inspector. |
ENS 52496 | 19 January 2017 00:39:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10 CFR 50.72(b)(3)(v)(C), event or condition that could have prevented fulfillment of a safety function needed to control the release of radioactive material and 10 CFR 50.72(b)(3)(v)(D), event or condition that could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident. An employee entered a secondary containment interlock (airlock) and identified that both doors of the interlock opened simultaneously when the door on the reactor building side was opened. The employee immediately secured both doors in the interlock and notified the Main Control Room Supervisor. Both doors in the interlock were open for approximately five seconds. With both doors open, TS SR 3.6.4.1.2 was not met. This rendered secondary containment inoperable per TS 3.6.4.1. Reactor Building differential pressure, as observed in the Main Control Room has remained less than -0.25 in. H2O at all times. Initial investigation determined that the interlock for the doors was malfunctioning. Administrative controls have been put in place to ensure the doors remain closed pending repairs to the interlock. The licensee notified the NRC Resident Inspector. Notified R3DO (McCraw). |
ENS 52472 | 2 January 2017 17:49:00 | LaSalle | NRC Region 3 | GE-5 | At approximately 1403 (CST) on January 2, 2017, LaSalle County Station was informed by the LaSalle County Sheriff that two warning sirens had malfunctioned at approximately 1252 earlier this afternoon. The warning sirens had inadvertently operated for nearly 3 minutes during maintenance at the LaSalle County 911 Communications Center. The warning sirens have been restored to standby and are fully functional. No other emergency notification systems or sirens were affected. The licensee has notified the NRC Resident Inspector of the issue. |
ENS 52227 | 8 September 2016 14:50:00 | LaSalle | NRC Region 3 | GE-5 | On July 11, 2016, at approximately 0430 CDT, while Unit 1 was operating at 100% power, the 1A Reactor Protection System (RPS) Motor Generator (M/G) set tripped causing a loss of the A RPS bus. This caused the complete actuation of the Division 1 (outboard) primary containment isolation logic. The isolation logic actuation resulted in successful closure of the Division 1 primary containment isolation valves. This was an event that resulted in the actuation of a general containment isolation signal affecting more than one system. However, as this event meets the definition of an invalid actuation (i.e., not a response to an actual plant parameter exceeding a trip set-point), this notification is being made in accordance with 10CFR50.73(a)(2)(iv)(A) in lieu of a Licensee Event Report. In response to the trip of the 1A RPS M/G Set, operators swapped the A RPS bus to the alternate power supply using the applicable response procedure. The containment isolation signal was reset and the systems were restored to their normal lineup. Reactor power was not affected by this event. All safety related equipment controlled by the affected primary containment isolation circuits operated as designed. The 1A RPS M/G Set trip was due to a blown power fuse for the 1A RPS M/G Set. This was the result of worn insulation on one of the generator output leads. The generator output leads were repaired and rerouted to prevent future problems on 07/15/16. Restoration of the normal power supply to the 1A RPS function was completed on 7/19/16. The licensee informed the NRC Resident Inspector. |
ENS 52104 | 18 July 2016 23:29:00 | LaSalle | NRC Region 3 | GE-5 | This telephone notification is provided in accordance with the Exelon Reportability manual, 'Major Loss of Emergency Preparedness Capabilities', and 10 CFR 50.72(b)(3)(xiii). On July 18, 2016 at 1500 CDT, it was determined during testing of the Everbridge ERO (Emergency Response Organization) notification system that the system would not notify the corporate EOF (Emergency Operations Facility) individuals if the system had been activated. This constitutes a loss of offsite communication capability. Exelon and Everbridge have identified and corrected this issue. A follow-up test of the LaSalle Everbridge ERO notification system was completed satisfactorily on July 18, 2016 at 2100. The Emergency Response Data System (ERDS) capability was not lost. The licensee has notified the (NRC) Senior Resident Inspector of the issue. Compensatory measures were in place during this event. |
ENS 51741 | 17 February 2016 17:05:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10 CFR 50.72(b)(3)(v)(C), event or condition that could have prevented fulfillment of a safety function needed to control the release of radioactive material and 10 CFR 50.72(b)(3)(v)(D), an event or condition that could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident. An employee entered a secondary containment interlock and identified that both doors of the interlock opened simultaneously when the door on the reactor building side was opened. The employee immediately secured both doors in the interlock and notified the Main Control Room Supervisor. Both doors in the interlock were open for approximately 5 seconds. With both doors open, TS SR 3.6.4.1.2 was not met. This rendered secondary containment inoperable per TS 3.6.4.1. Reactor Building differential pressure, as observed in the Main Control Room, has remained less than -0.25 inches H20 at all times. Initial investigation determined that a mechanical interlock for the doors was malfunctioning. Administrative controls have been put in place to ensure the doors remain closed pending repairs to the interlock. The licensee has notified the NRC Resident Inspector. |
ENS 51725 | 11 February 2016 01:20:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10CFR50.72(b)(3)(v)(C), event or condition that could have prevented fulfillment of a safety function needed to control the release of radioactive material and 10CFR50.72(b)(3)(v)(D), event or condition that could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident. LaSalle Station's Unit 1 and Unit 2 were in Mode 1. At 2207 (CST) (on 2/10/16), Secondary Containment Differential Pressure dropped below the Technical Specification (TS) 3.6.4.1 minimum of 0.25 inches water vacuum. The initial indications are a failure of one Unit 1 Reactor Building Exhaust Isolation Damper, which resulted in a trip of the Unit 1 Reactor Building Exhaust Fans. At 2245, Secondary Containment Differential Pressure was restored to within the TS 3.6.4.1 limits by securing and isolating the Unit 1 Reactor Building Ventilation System. Troubleshooting plans are being developed to determine cause of the damper failure and to correct the deficient condition. The licensee has notified the NRC Resident Inspector. |
ENS 51530 | 11 November 2015 19:40:00 | LaSalle | NRC Region 3 | GE-5 | At 1344 CST on 11/11/15, the seismic monitor was found inoperable. The seismic monitor was inoperable such that emergency classification at the ALERT level could not be obtained with site instrumentation. The loss of assessment capability is reportable to the NRC within 8 hours of discovery in accordance with 10 CFR 50.72(b)(3)(xiii). (The NRC) Senior Resident Inspector has been notified. |
ENS 51318 | 13 August 2015 16:52:00 | LaSalle | NRC Region 3 | GE-5 | A licensed, non-supervisory employee had a confirmed positive for alcohol during a random fitness-for-duty test. The employee's access to the plant has been terminated. The licensee notified the NRC Resident Inspector as well as the NRC Region 3 Office Safeguards Inspector. |
ENS 51300 | 7 August 2015 19:58:00 | LaSalle | NRC Region 3 | GE-5 | This notification is being provided in accordance with 10 CFR 50.72(b)(3)(ii)A, Degraded Condition. At 1340 CDT on 8/7/15, on LaSalle Unit 2, a through-wall (welded joint) leak was identified on a 3/4 inch vent line off of the bonnet of the 2B33-F067B, 2B Reactor Recirculation Pump Discharge Valve. This condition qualifies as pressure boundary leakage, which requires entry into Technical Specification 3.4.5, Reactor Coolant System Operational Leakage, Required Action C, to be in Mode 4, Cold Shutdown, by 0140 on 8/9/15. This leakage is significantly less than 10 gpm (leak rate is 0.2 gpm) and therefore, does not meet the threshold for entry into the Emergency Action Plan. At the time of discovery, Unit 2 was in Mode 3 - Hot Shutdown, heading into Cold Shutdown for a planned maintenance outage. This event does not affect Unit 1. The licensee notified the NRC Resident Inspector. |
ENS 51247 | 22 July 2015 07:08:00 | LaSalle | NRC Region 3 | GE-5 | (At) 0013 CDT, (on) 7/22/15, the seismic monitor was found inoperable. The seismic monitor was inoperable such that emergency classification at the ALERT level could not be obtained with site instrumentation. The loss of assessment capability is reportable to the NRC within 8 hours of discovery in accordance with 10 CFR 50.72(b)(3)(xiii). (The NRC) Senior Resident Inspector has been notified. |
ENS 51213 | 8 July 2015 21:53:00 | LaSalle | NRC Region 3 | GE-5 | This telephone notification is provided in accordance with Exelon Reportability manual SAF 1.10, 'Major Loss of Emergency Preparedness Capabilities', and 10CFR50.72(b)(3)(xiii). On July 8th 2015 at 1837 (CDT), it was determined that the onsite Technical Support Center (TSC) Ventilation System Supply Fan belts had failed, resulting in loss of ventilation for the facility. Repairs were not completed within the time required had the TSC needed to be staffed. There is currently no emergency event in progress requiring TSC staffing. If an emergency is declared and the TSC ERO (Emergency Response Organization) activation is required, the TSC will be staffed and activated unless the TSC becomes uninhabitable due to ambient temperatures, radiological, or other conditions. If relocation of the TSC staff becomes necessary, the Station Emergency Director will relocate the staff to an alternate TSC location in accordance with applicable site procedures. The licensee has notified the (NRC) Senior Resident Inspector of the issue.
After repairs were completed, the TSC Ventilation was restarted on 7/9/15 at 0625 EDT for a maintenance run, the TSC Ventilation was restored to operable status at 1500 EDT on 07/11/2015. The licensee has notified the NRC Resident Inspector. Notified R3DO (Stone). |
ENS 51205 | 8 July 2015 07:04:00 | LaSalle | NRC Region 3 | GE-5 | At 0130 (CDT) on 7/8/15, the seismic monitor was found inoperable. The seismic monitor was inoperable such that emergency classification at the Alert level could not be obtained with site instrumentation. The seismic monitor was restored to operable status within 11 minutes. The loss of assessment capability is reportable to the NRC within 8 hours of discovery in accordance with 10 CFR 50.72(b)(3)(xiii). The licensee has notified the NRC Resident Inspector. |
ENS 51164 | 17 June 2015 23:39:00 | LaSalle | NRC Region 3 | GE-5 | On June 17th, 2015 at 1841 CDT, it was determined that the onsite Technical Support Center (TSC) Ventilation System return damper 0VS119Y was failed closed, the failed closed damper affects the TSC Emergency Makeup Train filtration efficiency. There is currently no emergency event in progress requiring TSC staffing. If an emergency is declared and the TSC ERO (Emergency Response Organization) activation is required, the TSC will be staffed and activated unless the TSC becomes uninhabitable due to ambient temperatures, radiological, or other conditions. If relocation of the TSC staff becomes necessary, the Station Emergency Director will relocate the staff to an alternate TSC location in accordance with applicable site procedures. The licensee has notified the (NRC) Senior Resident Inspector of the issue.
After repairs were completed, the TSC Ventilation was restored to service at 1650 EDT on 06/18/2015. The licensee has notified the NRC Resident Inspector. Notified R3DO (Pelke). |
ENS 51133 | 6 June 2015 17:22:00 | LaSalle | NRC Region 3 | GE-5 | The following was received via fax and phone: This telephone notification is provided in accordance with Exelon Reportabllity manual SAF 1.1 0, 'Major Loss of Emergency Preparedness Capabilities', and 10CFR50.72(b)(3)(xiii). On June 6th 2015 at 12:13 (CDT), it was determined that the onsite Technical Support Center (TSC) Ventilation System Supply Fan belts had failed, resulting in loss of ventilation for the facility. Repairs were not completed within the time required had the TSC needed to be staffed. There is currently no emergency event in progress requiring TSC staffing. If an emergency is declared and the TSC ERO activation is required, the TSC will be staffed and activated unless the TSC becomes uninhabitable due to ambient temperatures, radiological, or other conditions. If relocation of the TSC staff becomes necessary, the Station Emergency Director will relocate the staff to an alternate TSC location in accordance with applicable site procedures. The licensee has notified the Senior Resident Inspector of the issue.
After repairs were completed, the TSC ventilation was restored to service at 2300 (EDT) on 06/06/2015. The licensee has notified the NRC Resident Inspector. Notified R3DO (Passehl) via email |
ENS 51054 | 7 May 2015 17:51:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10CFR50.72(b)(2)(xi), News Release or Notification of Other Government Agency. Operations received a report from Security that a fishing boat has capsized on the station cooling lake. At 1530 (CDT) the LaSalle County Operating Department was notified that the LaSalle County Coroner confirmed that there was a fatality. The Illinois Department of Natural Resources (IDNR), LaSalle County Sheriff, Seneca Rescue Team, and NRC Senior Resident Inspector have been notified. |
ENS 50926 | 26 March 2015 15:19:00 | LaSalle | NRC Region 3 | GE-5 | LaSalle Station has completed a review of seismic monitor performance. The seismic monitor is currently operable; however, this review identified 6 times in the past 3 years that the seismic monitor was inoperable such that emergency classification at the ALERT level could not be obtained with site instrumentation. The seismic monitor was determined to be inoperable on the following dates: 1) January 28, 2015 2) May 28, 2014 3) January 1, 2014 4) August 5, 2013 5) April 17, 2013 6) April 10, 2012 These unplanned inoperable conditions of the seismic monitor were entered into the LaSalle Corrective Action Program when they occurred. While Exelon procedural direction allowed the use of offsite sources to obtain seismic data when the seismic monitor is incapable of assessing emergency plan Emergency Action Levels (EALs), this was not explicitly referenced in the approved EALs. The loss of assessment capability is reportable to the NRC within 8 hours of discovery in accordance with 10 CFR 50.72(b)(3)(xiii). This report is required per 10 CFR 50.72(a)(1)(ii) as an event that occurred within 3 years of the date of discovery. The licensee has notified the NRC Resident Inspector. |
ENS 50827 | 17 February 2015 15:35:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10 CFR 50.72(b)(3)(v)(C), event or condition that could have prevented fulfillment of a safety function needed to control the release of radioactive material and 10 CFR 50.72(b)(3)(v)(D), event or condition that could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident. LaSalle's Station Unit 1 was in Mode 1 and Unit 2 was in Mode 5 for its scheduled refuel outage. There was no movement of irradiated fuel or CORE ALTERATIONS at the time. OPDRVs (Operations with Potential to Drain the Reactor Vessel) were in progress in the secondary containment on Unit 2. An employee entered a secondary containment interlock and identified that both doors of the interlock opened simultaneously when the door on the reactor building side was opened. The employee immediately secured both doors in the interlock and notified the main control room supervisor. Both doors in the interlock were open for somewhere between 5-10 seconds. With both doors open, TS SR 3.6.4.1.2 was not met and this rendered secondary containment inoperable per TS 3.6.4.1. Reactor building differential pressure, in the main control room, was never observed to be less than -0.25 inches of water column. Initial investigation determined that the interlock for the doors was malfunctioning. Administrative controls have been put in place to ensure the doors remain closed pending repairs to the interlock. The NRC Resident Inspector has been notified. |
ENS 50707 | 30 December 2014 03:51:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10CFR50.72(b)(3)(v)(D), Event or Condition that could have prevented fulfillment of a Safety Function needed to Mitigate the Consequences of an Accident. During routine surveillance testing of the Unit 2 Division 3 Emergency Diesel Generator (LOS-DG-M3) a small pinhole leak was identified in the pump casing of the Division 3 Diesel Generator Cooling Water Pump. This condition has been evaluated and the Division 3 Diesel Generator Cooling Water Pump has been declared inoperable. The Division 3 Diesel Generator Cooling Water Pump is a support system for the Division 3 Emergency Diesel Generator and the High Pressure Core Spray System (HPCS). The required actions of Technical Specification (TS) 3.5.1 were entered on 12/29/14 at 2330 (CST) when the HPCS system was determined to be inoperable. This condition could have prevented the High Pressure Core Spray System (HPCS), a single train safety system, from performing its design function. The licensee notified the NRC Resident Inspector. |
ENS 50675 | 12 December 2014 21:15:00 | LaSalle | NRC Region 3 | GE-5 | Engineering 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 50674 | 12 December 2014 18:20:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10CFR50.72(b)(3)(v)(C), 'Event or Condition that could have prevented fulfillment of a Safety Function needed to Control the Release of Radioactive Material' and 10CFR50.72(b)(3)(v)(D), 'Event or Condition that could have prevented fulfillment of a Safety Function needed to Mitigate the Consequences of an Accident.' Unit 1 and Unit 2 were in Mode 1 and no movement of irradiated fuel, core alterations, or OPDRVs (Operations with the Potential to Drain the Reactor Vessel) were in progress in the secondary containment. An employee entered a secondary containment interlock and identified that both doors of the interlock opened simultaneously when the door on the reactor building side was opened. The employee immediately secured both doors in the interlock and notified the Main Control Room Supervisor. Both doors in the interlock were open for approximately 10 seconds. With both doors open, TS SR 3.6.4.1.2 was not met. This rendered secondary containment inoperable per TS 3.6.4.1. Reactor building differential pressure, as observed in the Main Control Room, has remained less than -0.25 inches of water column at all times. Initial investigation determined that the interlock for the doors was malfunctioning. Administrative controls (barricades and signs) have been put in place to ensure the doors remain closed pending repairs to the interlock. The licensee notified the NRC Resident Inspector. |
ENS 50464 | 17 September 2014 09:21:00 | LaSalle | NRC Region 3 | GE-5 | This telephone notification is provided in accordance with 10CFR50.72(b)(3)(xiii), 'Major Loss of Emergency Preparedness Capabilities.' On September 17th, 2014, at 0800 (CDT), the Exelon LaSalle Station Technical Support Center (TSC) ventilation system was removed from service for planned TSC ventilation system maintenance. The removal of the ventilation system potentially affects the TSC habitability during a declared emergency requiring activation. The Emergency Response Organization (ERO) team has been notified of the maintenance and the possible need to relocate during an emergency. If an emergency is declared and the TSC ERO activation is required, the TSC will be staffed and activated unless the TSC becomes uninhabitable due to ambient temperatures, radiological, or other conditions. If relocation of the TSC staff becomes necessary, the Station Emergency Director will relocate the staff to an alternate TSC location in accordance with applicable site procedures. The ventilation system is expected to be out of service for approximately 4 hours. The licensee has notified the (NRC) Senior Resident Inspector of the issue.
The scheduled TSC ventilation system maintenance is expected to be out of service for approximately an additional 7 hours. The licensee has notified the NRC Senior Resident Inspector of the issue. Notified R3DO (Dickson) |
ENS 50413 | 28 August 2014 18:26:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10CFR50.72(b)(3)(v)(D), Event or Condition that could have prevented fulfillment of a Safety Function needed to Mitigate the Consequences of an Accident. While the 'B' train of Auxiliary Electric Equipment Room HVAC was inoperable and out of service for emergent repairs due to an oil leak, the 'A' train of Auxiliary Electric Equipment Room HVAC became inoperable due to a failure of the liquid line solenoid valve. The Main Control Room Envelope consists of the Main Control Room and the Auxiliary Electric Equipment Room. Both the Control Room HVAC and the Auxiliary Electric Equipment Room HVAC systems are required to be operable in the current mode. This is a loss of safety function for a system that is intended to mitigate the consequences of an accident and is discussed in chapter 6 of the UFSAR and is Tech Spec required and is safety related. Also, the system, structure, or component (SSC) is inoperable in a required mode in the Tech Spec applicability and there is no redundant equipment in the same system that is operable. The required actions of Tech Spec 3.7.5 were entered for this event. Online Risk remains Green. The station is currently pursuing repairs to both trains. The licensee notified the NRC Resident Inspector. |
ENS 50398 | 25 August 2014 09:51:00 | LaSalle | NRC Region 3 | GE-5 | At 0757 CDT on 8/25/14, LaSalle Main Control Room received a fire alarm from the Unit 2 Reactor Building 807 foot elevation. Operators dispatched and confirmed no fire at 0817 CDT (20 min). At 0812 CDT (15 min) an unusual event (HU3) was declared due to not having verified no fire within 15 minutes of the alarm. No fire was confirmed and plans are in progress to terminate event. The NRC Resident Inspector has been notified. The licensee notified the Illinois Emergency Management Agency. Notified DHS SWO, FEMA Operation Center, FEMA National Watch Center, NICC, Nuclear SSA via email.
At 0915 CDT on 8/25/2014, the LaSalle Shift Emergency Director terminated the Unusual Event (HU3) which had been declared at 0812 CDT. No fire present was verified at 0817 CDT and required hourly firewatch is in place. Maintenance Department has begun efforts to locate and replace faulted detector or other degraded component. The licensee notified the NRC Resident Inspector and the Illinois Emergency Management Agency. Notified R3DO(Passehl), NRREO (Hiland), IRD (Gott). Notified DHS SWO, FEMA Operation Center, FEMA National Watch Center, NICC, Nuclear SSA via email. |
ENS 50346 | 5 August 2014 22:20:00 | LaSalle | NRC Region 3 | GE-5 | This notification is being provided pursuant with SAF 1.6 10CFR50.72(b)(2)(iv)(B) and SAF 1.7 10CFR50.72(b)(3)(iv)(A). At 1734 CDT on August 5, 2014, LaSalle Unit 2 automatically scrammed due to an RPS actuation. The MSIVs isolated on a Group 1 signal, the cause is under investigation. The reactor water cleanup system isolated during the transient. The plant is stable with Reactor Pressure Control being maintained by the Reactor Core Isolation Cooling System and SRVs and level being controlled by the Low Pressure Core Spray System. The plant is planned to remain in hot shutdown pending investigation of the trip." The Unit 2 electric plant is in a normal shutdown lineup. All control rods inserted fully on the scram. Unit 1 was not affected by the Unit 2 transient. The licensee notified the NRC Resident Inspector.
The initial notification to the NRC stated that the reactor water cleanup system had isolated during the transient. The actual status is being corrected to state that the reactor water cleanup pump tripped during the transient. The licensee has notified the NRC Resident Inspector. Notified R3DO (Stone). |
ENS 50183 | 10 June 2014 16:25:00 | LaSalle | NRC Region 3 | GE-5 | A non-licensed employee supervisor had a confirmed positive for alcohol during a for-cause fitness-for-duty test. The employee's access to the plant has been suspended. The licensee notified the NRC Resident Inspector and the Regional Safeguards Inspector. |
ENS 50076 | 30 April 2014 17:36:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10CFR50.72(b)(3)(v)(C), Event or Condition that could have prevented fulfillment of a Safety Function needed to Control the Release of Radioactive Material and 10CFR50.72(b)(3)(v)(D), Event or Condition that could have prevented fulfillment of a Safety Function needed to Mitigate the Consequences of an Accident. Unit 1 was in mode 1 and in a condition of moving irradiated fuel in the secondary containment. Unit 2 was in mode 5 and in the condition of moving irradiated fuel in the secondary containment, core alterations, and operations with the potential to drain the reactor vessel. An employee entered a secondary containment interlock (Unit 2) and identified that both doors of the interlock opened simultaneously when the door on the auxiliary building side was opened. The employee immediately secured both doors in the interlock and notified the Main Control Room Supervisor. Both doors in the interlock were open for approximately 5 seconds. With both doors open, TS SR 3.6.4.1.2 (Technical Specification Surveillance Requirement) was not met. This rendered secondary containment inoperable per TS 3.6.4.1. Reactor Building differential pressure, as observed in the Main Control Room, has remained less that -0.25 inches of water column at all times. Initial investigation determined that the interlock for the doors was malfunctioning. Administrative controls have been put in place to ensure the doors remain closed pending repairs to the interlock. The licensee has notified the NRC Resident Inspector. |
ENS 49973 | 29 March 2014 23:49:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to SAF 1.8, 10 CFR 50.72(b)(3)(v)(D), Event or Condition that could have prevented fulfillment of a Safety Function needed to Mitigate the Consequences of an Accident. During steady state operations on Unit 1 at 1620 (CDT) hrs. on 3/29/14, the Division 3 Core Standby Cooling System (CSCS) Pump Room, SWGR Room, and Battery Room Ventilation failed in such a manner that heat could not be removed from the rooms. These Division 3 systems supply power and cooling water to the High Pressure Core Spray system (HPCS), which is a single-train system. The HPCS system and its associated power supplies were declared inoperable based on long-term temperature considerations. The system remains available due to manual damper adjustments that than can be made per an approved procedure. The licensee will notify the NRC Resident Inspector. |
ENS 49840 | 18 February 2014 22:15:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10CFR50.72(b)(3)(v)(C), Event or Condition that could have prevented fulfillment of a Safety Function needed to Control the Release of Radioactive Material. An employee entered a secondary containment (airlock) interlock and identified that both doors of the interlock opened simultaneously when the door on the reactor building side was opened. The employee immediately secured both doors in the interlock and notified the Main Control Room Supervisor. Both doors in the interlock were open for approximately 3 seconds. With both doors open, TS SR 3.6.4.1.2 was not met. This rendered secondary containment inoperable per TS 3.6.4.1. Reactor Building differential pressure, as observed in the Main Control Room, has remained less than -0.25 inches H2O at all times. Initial investigation determined that a mechanical interlock for the doors was malfunctioning. Administrative controls have been put in place to ensure the doors remain closed pending repairs to the mechanical interlock. The licensee notified the NRC Resident Inspector. |
ENS 49776 | 29 January 2014 18:33:00 | LaSalle | NRC Region 3 | GE-5 | This telephone notification is provided in accordance with Exelon Reportability manual SAF 1.10, 'Major Loss of Emergency Preparedness Capabilities', and 10 CFR 50.72(b)(3)(xiii). On January 29th at 09:53 CST, it was determined that the onsite Technical Support Center (TSC) Ventilation System Supply Fan had failed (due to failed fan belts as a result of degraded alignment), resulting in loss of ventilation for the TSC. Repairs have been initiated, however repairs will not have been completed within the time required to staff the TSC. There is currently no emergency event in progress requiring TSC staffing. The Main Control Room remains available as an Emergency Response Facility (ERF), should an event occur requiring Emergency Response Facilities to be staffed. The licensee has notified the Senior Resident Inspector of the issue.
After repairs were completed, the TSC Ventilation was restored to service at (2350 CST on 01/30/2014). The licensee has notified the NRC Resident Inspector. Notified the R3DO (Sheldon). |
ENS 49615 | 8 December 2013 06:09:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10CFR50.72(b)(3)(v)(A), event or condition that at the time of discovery could have prevented the fulfillment of a safety function of systems that are needed to shutdown the reactor and maintain it in a safe shutdown condition. A scheduled load reduction for surveillance testing and control rod sequence exchange was in progress. During the control rod sequence exchange, the core monitoring software system (3DMonicore) was used to obtain a 'case' which records various calculated and actual core parameters (i.e. core thermal power, Power Range Monitor indication). The 'case' data is used to evaluate the Technical Specification (TS) Surveillance Requirement (SR) acceptance criteria for SR 3.3.1.1.2 to verify the absolute difference between the average power range monitor (APRM) channels and the calculated power is less than or equal to 2% rated thermal power (RTP) while operating at greater than or equal to 25% RTP. The 'case' showed that all 3 A RPS Trip System APRM channels exceeded the allowable 2% difference threshold in the non-conservative direction (i.e. APRM power reading less than calculated thermal power, difference of 2.9, 3.1, and 2.5% respectively). TS 3.3.1.1 requires at least 2 operable APRM channels per trip system (there are 2 RPS trip systems, A and B). At least 1 of 2 TS required APRM channels are required to maintain the Safety Function (i.e. SCRAM). In this situation, none of the A RPS TS required APRM channels met their SR and were declared inoperable. TS 3.3.1.1 allows delaying entry into the associated Condition and Required Action for this inoperability for up to 2 hours when the inoperability is solely due to APRM indication not within the 2% limit; therefore no TS Required Action tracking timeclocks were entered. A confirmatory 'case' was performed that validated that the subject SR was not met. Prompt action was taken to restore the APRM indications to within limits (this action took approximately 22 minutes to complete) and the subject APRMs were declared operable, restoring the A RPS Safety Function. The licensee notified the NRC Resident Inspector and the Illinois Emergency Management Agency. |
ENS 49574 | 22 November 2013 23:59:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10CFR50.72(b)(3)(v)(D), Event or Condition that could have prevented fulfillment of a Safety Function needed to Mitigate the Consequences of an Accident. While the 'A' Train of Control Room HVAC was inoperable and out of service for emergent repairs due to a Freon leak, the 'B' Train of Auxiliary Electric Room HVAC became inoperable due to a failure of the Cooler Condenser Fan. The Main Control Room Envelope consists of the Main Control Room and the Auxiliary Electric Equipment Room. Both the Control Room HVAC and the Auxiliary Electric Equipment Room HVAC Systems are required to be Operable in the current Mode. This is a loss of safety function for a system that is intended to mitigate the consequences of an accident and is discussed in Chapter 6 of the UFSAR and is Tech Spec required and is Safety Related. Also, the system, structure, or component (SSC) is inoperable in a required mode in the Tech Spec Applicability and there is no redundant equipment in the same system that is operable. The Required actions of Tech Spec 3.7.5 were entered on 11/22/2013 at 1920 CST when the 'B' train became inoperable. Online Risk remains Green. The station is currently pursuing repairs to both trains. The NRC Resident Inspector has been notified by the licensee. |
ENS 49462 | 22 October 2013 15:34:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10CFR50.72(b)(3)(v)(C), 'Event or condition that could have prevented fulfillment of a safety function needed to control the release of radioactive material.' An employee entered a secondary containment interlock and while the door was closing, another employee opened the other secondary containment interlock door thereby having two doors open. The employee immediately secured both doors in the interlock and notified the main control room supervisor. Both doors in the interlock were open for approximately 10 seconds. With both doors open, TS SR 3.6.4.1.2 was not met. This rendered secondary containment inoperable per TS 3.6.4.1. Reactor Building differential pressure, as observed in the main control room, has remained satisfactory and less than -0.25 inches of H20 at all times. Initial investigation determined that a mechanical interlock for the doors was malfunctioning. Administrative controls have been put in place to ensure the doors remain closed pending repairs to the mechanical interlock. The licensee has notified the NRC Resident Inspector. |
ENS 49174 | 5 July 2013 12:34:00 | LaSalle | NRC Region 3 | GE-5 | On May 22, 2013, at approximately 1134 CDT, while Unit 1 was operating at 100% power, the 1A Reactor Protection System (RPS) Motor Generator (M/G) set tripped causing a loss of the A RPS bus. This caused the actuation of the Division 1 (outboard) primary containment isolation logic. This was an event that resulted in the actuation of a general containment isolation signal affecting more than one system. However, as this event meets the definition of an invalid actuation (i.e. not a response to an actual plant parameter exceeding a trip setpoint), this notification is being made in accordance with 10 CFR 50.73(a)(1) in lieu of a Licensee Event Report. In response to the trip of the 1A RPS M/G, operators swapped the A RPS bus to the alternate power supply using the applicable response procedure. The containment isolation signal was reset and the systems were restored to their normal lineup. Reactor power was not affected by this event. All safety related equipment controlled by the affected primary containment isolation circuits operated as designed. The 1A RPS M/G trip was due to a motor fault requiring motor replacement. Replacement of the motor was completed on 5/26/13 and the A RPS bus was restored to its normal power supply on 5/27/13. The licensee has notified the NRC Resident Inspector. |
ENS 49167 | 1 July 2013 21:47:00 | LaSalle | NRC Region 3 | GE-5 | This report is being made pursuant to 10CFR50.72(b)(3)(v)(D), Event or Condition that could have prevented fulfillment of a Safety Function needed to Mitigate the Consequences of an Accident. During routine Instrument Maintenance Surveillance Testing (LIS-HP-205), the High Pressure Core Spray System (HPCS) minimum flow valve pressure switch set point was found outside the Technical Specification allowable value. This could have prevented the High Pressure Core Spray System (HPCS), a single train safety system, from performing its design function. This is reportable as an 8 hour ENS notification. The required actions of Technical Specification (TS) 3.5.1 were entered on 7/01/13 at 1646 (CDT) when the system was made inoperable for surveillance testing. At 1705, maintenance personnel reported minimum flow valve pressure switch set point was found at 112.6 psig, which is outside of the TS Allowable Value of greater than or equal to 113.2 psig (0.6 psig below the Allowable Value). The minimum flow valve pressure switch set point has been calibrated and was left within Technical Specification allowable values, HPCS was declared OPERABLE at 1815 on 7/01/13." The licensee has notified the NRC Resident Inspector.
The event notification was reported by LaSalle Generating Station on 7/01/2013 at 2147 EDT. This update is being provided for the purposes of retracting that notification. On July 1, 2013, during surveillance testing, the Unit 2 High Pressure Core Spray System (HPCS) minimum flow valve pressure switch setpoint was found below the Technical Specification (TS) 3.3.5.1 allowable value. HPCS was declared inoperable, and TS Required Actions (RA) were entered on July 1, 2013, at 1646 hours (CDT). Because HPCS is a single train system, an ENS report was made pursuant to 10 CFR 50.72(b)(3)(v)(D), as an event or condition that could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident. The minimum flow valve pressure switch setpoint was calibrated to within TS allowable values, and HPCS was declared operable on July 1, 2013, at 1815 hours. A post-event review determined that declaring HPCS inoperable was not required. The inoperability of the pressure switch would not have impacted the function of the HPCS minimum flow valve to automatically open as required to prevent overheating of the HPCS pump. The as-found setpoint was 0.6 psig below the TS allowable value, which would have resulted in the minimum flow valve opening slightly sooner. The inoperability would also not have prevented or delayed the automatic closing of the valve at the required system flow to assure that adequate ECCS flow is available. It should be noted that the LaSalle ECCS (Emergency Core Cooling System) LOCA (Loss Of Coolant Accident) analysis assumes that the HPCS minimum flow valve is open during an injection. TS 3.3.5.1 RA D.4 requires that the minimum flow valve pressure switch be restored to operable status within 7 days. If it cannot be restored within that time, RA G.1 requires that the supported system (HPCS) be declared inoperable, precluding extended operation with the minimum flow pressure switch inoperable. The pressure switch was re-calibrated to within TS allowable values within approximately 1 hour and 29 minutes of being declared inoperable. Therefore, the HPCS system was operable with the minimum flow pressure switch 0.6 psig out of calibration for 1 hour and 29 minutes. This event did not constitute a loss of safety function of the HPCS system, and the event was not reportable under 10 CFR 50.72(b)(3)(v)(D). The licensee has notified the NRC Resident Inspector. Notified R3DO (Lara). |