07-17-2017 | On May 17, 2017 at 0908 CDT, during Unit 1 full-power operations, operators received an unexpected alarm for the Low Pressure Core Spray ( LPCS) pump injection high flow and automatic closure of the LPCS minimum flow valve ( 1E21-F011). Inspections indicated the flow switch that actively controls the LPCS minimum flow valve had a faulty diaphragm which allowed for water intrusion into the device. There were no impacts on plant operations. The required actions of Technical Specifications 3.5.1, " ECCS - Operating" and TS 3.3.5.1, " Emergency Core Cooling System ( ECCS) Instrumentation" were entered. The switch was replaced and LPCS system tested, which allowed full restoration of the system on May 17, 2017 at 18:45 CDT.
This condition could have prevented the LPCS system from performing its design function. This condition is reportable in accordance with 10 CFR 50.73(a)(2)(v)(D) as an event or condition that could have prevented fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. There was minimal safety consequences associated with the condition since other emergency safety systems remained operable. |
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Category:Letter
MONTHYEARML24249A1362024-09-0404 September 2024 EN 57304 - Westinghouse Electric Company, LLC, Final Report - No Embedded Files. Notification of the Potential Existence of Defects Pursuant to 10 CFR Part 21 IR 05000373/20240052024-08-29029 August 2024 Updated Inspection Plan and Assessment Follow-Up Letter for Lasalle County Station (Report 05000373/2024005; 05000374/2024005) IR 05000373/20244022024-08-28028 August 2024 County Station - Cyber Security Inspection Report 05000373/2024402 and 05000374/2024402 ML24239A3972024-08-23023 August 2024 Rssc Wire & Cable LLC Dba Marmon - Part 21 Final Notification - 57243-EN 57243 IR 05000373/20240022024-08-13013 August 2024 County Station - Integrated Inspection Report 05000373/2024002 and 05000374/2024002 ML24222A6772024-08-0909 August 2024 Response to Request for Additional Information for Application to Revise Technical Specifications to Adopt TSTF-591-A, “Revise Risk Informed Completion Time (RICT) Program” Revision 0 and Revise 10 CFR 50.69 License Condition IR 05000373/20244202024-08-0505 August 2024 County Station - Security Baseline Inspection Report 05000373 2024420 and 05000374 2024420 ML24208A0962024-07-25025 July 2024 57243-EN 57243 - Rssc Wire & Cable LLC, Dba Marmon - Part 21 Notification RS-24-064, Nuclear Radiological Emergency Plan Document Revisions2024-06-28028 June 2024 Nuclear Radiological Emergency Plan Document Revisions ML24178A2522024-06-27027 June 2024 County Station – Acknowledgement of Response to NRC Inspection Report 05000373/2024001 and 05000374/2024001 and Disputed Non-Cited Violation RS-24-061, Constellation Energy Generation, LLC, Response to NRC Regulatory Issue Summary 2024-01, Preparation and Scheduling of Operator Licensing Examinations2024-06-14014 June 2024 Constellation Energy Generation, LLC, Response to NRC Regulatory Issue Summary 2024-01, Preparation and Scheduling of Operator Licensing Examinations IR 05000373/20240102024-05-29029 May 2024 County Station - Commercial Grade Dedication Inspection Report 05000373/2024010 and 05000374/2024010 ML24079A0762024-05-23023 May 2024 Issuance of Amendments to Adopt TSTF 264 ML24142A3352024-05-21021 May 2024 Quad Cities—Information Request to Support the NRC Annual Baseline Emergency Action Level and Emergency Plan Changes RS-24-055, 2023 Corporate Regulatory Commitment Change Summary Report2024-05-17017 May 2024 2023 Corporate Regulatory Commitment Change Summary Report IR 05000373/20240012024-05-13013 May 2024 County Station - Integrated Report 05000373/2024001 and 05000374/2024001 RS-24-038, Relief Request Concerning Extension of Permanent Relief from Ultrasonic Examination of Reactor Pressure Vessel Circumferential Shell Welds2024-05-0202 May 2024 Relief Request Concerning Extension of Permanent Relief from Ultrasonic Examination of Reactor Pressure Vessel Circumferential Shell Welds RS-24-041, Alternative Request to Utilize Code Case OMN-32, Alternative Requirements for Range and Accuracy of Pressure, Flow, and Differential Pressure Instruments Used in Pump Tests2024-04-30030 April 2024 Alternative Request to Utilize Code Case OMN-32, Alternative Requirements for Range and Accuracy of Pressure, Flow, and Differential Pressure Instruments Used in Pump Tests ML24108A1562024-04-15015 April 2024 Updated Final Safety Analysis Report (Ufsar), Revision 26 and Fire Protection Report (Fpr), Revision 11 ML24103A2042024-04-12012 April 2024 Constellation Energy Generation, LLC, Application to Revise Technical Specifications to Adopt TSTF-591-A, Revise Risk Informed Completion Time (RICT) Program Revision 0 and Revise 10 CFR 50.69 License Condition RS-24-002, Constellation Energy Generation, LLC - Annual Property Insurance Status Report2024-04-0101 April 2024 Constellation Energy Generation, LLC - Annual Property Insurance Status Report ML24071A2122024-03-12012 March 2024 County Station - Information Request for the Cyber-Security Baseline Inspection, Notification to Perform Inspection IR 05000373/20230062024-02-28028 February 2024 Annual Assessment Letter for Lasalle County Station, Units 1 and 2 (Report 05000373/2023006; 05000374/2023006) RS-24-014, Annual 10 CFR 50.46 Report of Emergency Core Cooling System Evaluation Model Changes and Errors2024-02-22022 February 2024 Annual 10 CFR 50.46 Report of Emergency Core Cooling System Evaluation Model Changes and Errors ML24024A1332024-01-24024 January 2024 Confirmation of Initial License Examination IR 05000373/20230042024-01-24024 January 2024 County Station - Integrated Inspection Report 05000373/2023004 and 05000374/2023004 IR 05000373/20230122024-01-18018 January 2024 County Station - Biennial Problem Identification and Resolution Inspection Report 05000373/2023012 and 05000374/2023012 ML23354A2902024-01-0505 January 2024 Exemption from Select Requirements of 10 CFR Part 73 (EPID L-2023-LLE-0028 (Security Notifications, Reports, and Recordkeeping and Suspicious Activity Reporting)) ML23360A6082023-12-27027 December 2023 County Station Request for Information for NRC Commercial Grade Dedication Inspection: Inspection Report 05000373/2024010 and 05000374/2024010 ML23278A1292023-12-14014 December 2023 Units 1 & 2; Limerick, Units 1 & 2; Nine Mile Point, Units 1 & 2; and Peach Bottom, Units 2 & 3 -Revision to Approved Alternatives to Use Boiling Water Reactor Vessel and Internals Project Guidelines ML23305A1402023-12-13013 December 2023 Units 1 & 2; Nine Mile Point, Unit 2; Peach Bottom, Units 2 & 3; and Quad Cities, Units 1 and 2 - Issuance of Amendments to Adopt Traveler TSTF-580 RS-23-120, Supplemental Information Letter for Part 73 Exemption Request - Responses to Request for Confirmatory Information2023-11-10010 November 2023 Supplemental Information Letter for Part 73 Exemption Request - Responses to Request for Confirmatory Information ML23317A1192023-11-10010 November 2023 Constellation Energy Generation, LLC - 2023 Annual Report - Guarantees of Payment of Deferred Premiums IR 05000373/20230032023-11-0909 November 2023 County Station Integrated Inspection Report 05000373/2023003, 05000374/2023003, and 07200070/2023001 ML23286A2602023-11-0808 November 2023 Issuance of Amendment Nos. 260 and 245 to Renewed Facility Operating Licenses Relocation of Pressure and Temperature Limit Curves to the Pressure Temperature Report IR 05000373/20234012023-11-0707 November 2023 County Station Security Baseline Inspection Report 05000373/2023401 and 05000374/2023401 RS-23-103, Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-10-13013 October 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation RS-23-097, Constellation Energy Generation, LLC, Advisement of Leadership Changes and Submittal of Updated Standard Practice Procedures Plans2023-10-12012 October 2023 Constellation Energy Generation, LLC, Advisement of Leadership Changes and Submittal of Updated Standard Practice Procedures Plans IR 05000374/20230102023-10-11011 October 2023 NRC Inspection Report 05000374/2023010 IR 05000373/20233012023-09-15015 September 2023 Errata to NRC Initial License Examination Report 05000373/2023301; 05000374/2023301 RS-23-080, Constellation Energy Generation, LLC, Application to Revise Technical Specifications to Adopt TSTF-264-A, Revision 0, 3.3.9 and 3.3.10 - Delete Flux Monitors Specific Overlap Requirement SRs2023-08-30030 August 2023 Constellation Energy Generation, LLC, Application to Revise Technical Specifications to Adopt TSTF-264-A, Revision 0, 3.3.9 and 3.3.10 - Delete Flux Monitors Specific Overlap Requirement SRs RS-23-087, Revision to Approved Alternatives Associated with the Use of the BWRVIP Guidelines in Lieu of Specific ASME Code Requirements on Reactor2023-08-0404 August 2023 Revision to Approved Alternatives Associated with the Use of the BWRVIP Guidelines in Lieu of Specific ASME Code Requirements on Reactor ML23212A9012023-08-0303 August 2023 Regulatory Audit Report to Support the Review of the Amendments to Relocation of the Pressure Temperature Limit Curves to the Pressure and Temperature Limits Report IR 05000373/20230022023-08-0101 August 2023 County Station - Integrated Inspection Report 05000373/2023002 and 05000374/2023002 ML23208A3182023-07-27027 July 2023 Notification of an NRC Biennial Licensed Operator Requalification Program Inspection and RFI RS-23-084, Response to Request for Additional Information Regarding the Application to Revise Design Basis to Allow Use of Plastic Section Properties in Lower Downcomer Braces Analysis2023-07-24024 July 2023 Response to Request for Additional Information Regarding the Application to Revise Design Basis to Allow Use of Plastic Section Properties in Lower Downcomer Braces Analysis ML23192A5272023-07-12012 July 2023 NRC Initial License Examination Report 05000373/2023301; 05000374/2023301 ML23186A2062023-07-0606 July 2023 Information Request for a NRC Post-Approval Site Inspection for License Renewal 05000374/2023010 ML23181A1502023-06-30030 June 2023 Combined Response to Request for Additional Information and Supplemental Information in Support of LAR to Relocate Pressure and Temperature Limit Curves to the Pressure and Temperature Limits Report ML23178A2422023-06-28028 June 2023 Reassignment of the U.S. Nuclear Regulatory Commission Branch Chief in the Division of Operating Reactor Licensing for Plant Licensing Branch III 2024-09-04
[Table view] Category:Licensee Event Report (LER)
MONTHYEAR05000373/LER-2017-0072017-08-18018 August 2017 Low Pressure Core Spray System Inoperable due to Loss of Cooling, LER 17-007-00 for LaSalle County Station, Unit 1, Regarding Low Pressure Core Spray System Inoperable due to Loss of Cooling 05000374/LER-2017-0032017-08-0909 August 2017 High Pressure Core Spray System Inoperable due to Injection Valve Stem-Disc Separation, LER 17-003-01 for LaSalle County Station, Unit 2 Regarding High Pressure Core Spray System Inoperable due to Injection Valve Stem-Disc Separation 05000374/LER-2017-0042017-07-14014 July 2017 Two Main Steam Safety Relief Valves Failed Inservice Lift Inspection Pressure Test, LER 17-004-01 for LaSalle, Unit 2, Regarding Two Main Steam Safety Relief Valves Failed Inservice Lift Inspection Pressure Test 05000373/LER-2017-0062017-07-14014 July 2017 Low Pressure Core Spray Inoperable due to Minimum Flow Valve Failure in Closed Position, LER 17-006-00 for LaSalle, Unit 1, Regarding Low Pressure Core Spray Inoperable due to Minimum Flow Valve Failure in Closed Position 05000373/LER-2017-0052017-04-18018 April 2017 Manual Reactor Scram Resulting From Feedwater Regulating Valve Failure Causing High Reactor Water Level, LER 17-005-00 for LaSalle County, Unit 1, Regarding Manual Reactor Scram Resulting From Feedwater Regulating Valve Failure Causing High Reactor Water Level 05000373/LER-2017-0042017-04-17017 April 2017 Secondary Containment Inoperable Due to Interlock Doors Open, LER 17-004-00 for LaSalle County, Unit 1, Regarding Secondary Containment Inoperable Due to Interlock Doors Open 05000373/LER-2017-0032017-04-14014 April 2017 Automatic Reactor Scram due to Main Generator Trip on Differential Current During Back-Feed Operations, LER 17-003-00 for LaSalle County Station, Unit 1, Regarding Automatic Reactor Scram due to Main Generator Trip on Differential Current During Back-Feed Operations 05000374/LER-2017-0022017-03-30030 March 2017 High Pressure Core Spray System Declared Inoperable due to Cooling Water Strainer Backwash Valve Stem-Disc Separation, LER 17-002-00 for LaSalle, Unit 2, Regarding High Pressure Core Spray System Declared Inoperable due to Cooling Water Strainer Backwash Valve Stem-Disc Separation 05000374/LER-2017-0012017-03-24024 March 2017 Manual Reactor Scram due to Turbine-Generator Run-Back Caused by Stem-Disc Separation in Stator Water Cooling Heat Exchanger Inlet Valve, LER 17-001-00 for LaSalle County, Unit 2 Regarding Manual Reactor Scram due to Turbine-Generator Run-Back Caused by Stem-Disc Separation in Stator Water Cooling Heat Exchanger Inlet Valve 05000373/LER-2017-0012017-02-0808 February 2017 Reactor Core Isolation Cooling System Inoperable Longer than Allowed by the Technical Specifications due to Low Suction Pressure Trips, LER 17-001-00 for LaSalle County, Unit 1, Regarding Reactor Core Isolation Cooling System Inoperable Longer than Allowed by the Technical Specifications due to Low Suction Pressure Trips 05000374/LER-2016-0012016-04-18018 April 2016 Secondary Containment Inoperable Due to Interlock Doors Open, LER 16-001-00 for LaSalle County, Unit 2, Regarding Secondary Containment Inoperable Due to Door Interlock Doors Open 05000373/LER-2016-0012016-04-11011 April 2016 Secondary Containment Inoperable due to Reactor Building Ventilation Damper Failure, LER 16-001-00 for LaSalle County, Unit 1 & 2, Regarding Secondary Containment Inoperable Due to Reactor Building Ventilation Damper Failure 2017-08-09
[Table view] |
Infocollects Resource@nrc gov, and to the Desk Officer, Office of Information and Regulatory Affairs, used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection 3. LER NUMBER 2. DOCKET NUMBER - 00 006
PLANT AND SYSTEM IDENTIFICATION
LaSalle County Station Unit 1 is a General Electric Boiling Water Reactor with 3546 Megawatts Thermal Rated Core Power.
The Low Pressure Core Spray (LPCS) system is part of the Division 1 Emergency Core Cooling System (ECCS). LPCS provides low-pressure coolant into the reactor core under accident conditions The LPCS minimum flow switch 1 E21-N004 monitors pump discharge flow. This flow switch initiates opening of LPCS minimum flow valve 1E21-F011, if flow drops below the set point (1325 gpm) and initiates closing of 1E21-F011, if flow rises above its reset point (1774 gpm).
CONDITION PRIOR TO EVENT
Unit(s). 1 Reactor Mode(s): 1 Event Date: May 17, 2017 Event Time: 0908 CDT Mode(s) Name: Power Operation Power Level: 100 percent
DESCRIPTION OF EVENT
At 0908 CDT on May 17, 2017, the Unit 1 Main Control Room received an unexpected alarm on panel 1H13-P601-0508 for the LPCS pump injection high flow and automatic closure of the LPCS minimum flow valve 1E21-F011. The automatic closure of the LPCS minimum flow valve occurred as appropriate for this alarm condition. An operator was dispatched, who verified that there were no abnormal conditions in the LPCS pump room and that there were no abnormal indications at the 1 E21-N004 flow switch, which is the device that initiates this alarm and subsequent actions. LPCS was declared inoperable and the appropriate Technical Specification (TS) required actions were entered in accordance with TS 3.5.1, "ECCS — Operating" and TS 3.3.5.1, "Emergency Core Cooling System (ECCS) Instrumentation." There were no related work activities in progress at the time the condition was identified The applicable TS required action (RA) entries were TS 3.5.1 RA A.1, restore LPCS to operable in 7 days; TS 3.3.5 1 RA A.1 to enter condition referenced in Table 3.3.5.1-1 for the LPCS pump discharge flow-low (bypass) channel; TS 3.3.5.1 RA D.1 to declare supported features inoperable when its redundant feature ECCS initiation capability is inoperable; and, TS 3.3.5.1 RA D.4 to restore the channel to operable in 7 days.
Instrument maintenance technicians inspected the LPCS minimum flow switch and found water intrusion in the switch electrical housing. This switch was removed and sent offsite for failure analysis. The failed switch was replaced and calibrated. Unit 1 LPCS was declared operable on May 17, 2017 at 18:45 CDT.
CAUSE OF EVENT
Water intrusion into the switch electrical housing for the LPCS minimum flow switch 1E21-N004 resulted in a ground fault causing the actuation of relay 1 E21-K006 and subsequent LPCS minimum flow valve closure. The flow switch was replaced with a like for like replacement, and the switch was sent to Power Labs for failure analysis. The cause was determined to be process water leakage past an internal "U-cup" seal around the shaft from the sensing element into the electrical switch housing. This failure has previously occurred with a similar model of flow switch used in another system's application.
The causal investigation concluded the design of this component was not optimal for its function. This was the first failure of this type noted with model 141N6-WX7-M9 that is utilized for residual heat removal (RHR) and LPCS minimum flow applications. A previous design change to improve the reliability of static 0-ring (SOR) differential pressure switches and associated failure analysis did not evaluate all SOR switches using the deficient U-cup design.
2017 Infocollects Resource@nrc goy, and to the Desk Officer, Office of Information and Regulatory Affairs, used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection 3. LER NUMBER 2. DOCKET NUMBER - 00 006 2017
REPORTABILITY AND SAFETY ANALYSIS
This event is reportable in accordance with 10 CFR 50 73(a)(2)(v)(D) as an event or condition that condition that could have prevented fulfillment of a safety function of structures or systems that are needed to mitigate the consequences of an accident An Emergency Notification System (ENS) report number 52761 was made on May 17, 2017 at 12:29 EDT.
The safety significance of this condition was minimal, as plant equipment responded as expected for the event; and all plant parameters remained within plant safety or design limits Additionally, other emergency safety systems remained operable and there were no related work activities in progress at the time the condition was identified.
The condition is a safety system functional failure (SSFF) defined in accordance with NEI 99-02, Regulatory Assessment Performance Indicator Guidance. The failure of the 1E21-N004 switch caused the minimum flow valve to close when not demanded. Although this did not prevent the LPCS pump from injecting into the vessel to perform its safety function, the conditions of the system upon an automatic start could cause the LPCS pump to run without a discharge path, causing failure of the pump due to a dead-head condition.
CORRECTIVE ACTIONS
The LPCS minimum flow switch 1 E21-N004 was replaced and LPCS system tested, which allowed full restoration of the system.
Investigation of the failure determined that cause was due to design of the U-cup used for this application. Additional corrective actions are to schedule the replacement of the current design of SOR differential pressure switches in other systems, as part of an extent of condition review, and to evaluate the failure analysis for additional actions as needed.
PREVIOUS OCCURRENCES
A review of station Licensee Event Reports in the past three years did not identify a similar occurrence. However, searches were also performed of the station's corrective action program (CAP) and INPO operating experience databases, which found the following similar occurrences.
- ICES 308842, Unexpected Isolation of Reactor Core Isolation Cooling (RCIC) System On June 13, 2013, a RCIC high steam flow differential pressure switch (SOR model 141N6-WX47-M9-C1A-JJTTNQ) was found to be in the tripped condition. When the leads to the switch were lifted, the relay causing the isolation signal dropped out. Upon further investigation, the switch was identified as having internal corrosion. It was determined that water leaked into the switch housing through a U-cup style seal and over time caused rust to build up on the switch internals eventually resulting in a false actuation and the isolation of RCIC. The switch was replaced, and the vendor developed a new design of the Model 141N6 switch that uses an 0-ring rather than the U-cup seal.
- ICES 312061, Failure of Differential Pressure Switch Due to Crack in Diaphragm On May 27, 2014, during an instrument surveillance, the equalizer valve for a SOR model 131N6-BX5-M9-C1A-JJTTNQ differential pressure switch (2E31-N010C Main Steam "C" High Flow Detection) was isolated. Leak-by of the equalizer valve was noted, which prevented completion of the calibration. This event necessitated switch replacement. Subsequent failure analysis identified that the leak-by was the result of a circumferential crack in the diaphragm in the switch. Due to redundancy in the system, this issue had no impact on system reliability or unit operation.
COMPONENT FAILURE DATA
Manufacturer: Static 0-Rink SOR Inc. (S382) Device (Model): Differential Pressure Switch (141N6-WX7-M9-C1A-JJTTNQ) Component ID: LPC Pump Discharge Flow Bypass Interlock (1 E21-N004)
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05000374/LER-2017-001 | Manual Reactor Scram due to Turbine-Generator Run-Back Caused by Stem-Disc Separation in Stator Water Cooling Heat Exchanger Inlet Valve LER 17-001-00 for LaSalle County, Unit 2 Regarding Manual Reactor Scram due to Turbine-Generator Run-Back Caused by Stem-Disc Separation in Stator Water Cooling Heat Exchanger Inlet Valve | 10 CFR 50.73(a)(2)(iv)(A), System Actuation | 05000373/LER-2017-001 | Reactor Core Isolation Cooling System Inoperable Longer than Allowed by the Technical Specifications due to Low Suction Pressure Trips LER 17-001-00 for LaSalle County, Unit 1, Regarding Reactor Core Isolation Cooling System Inoperable Longer than Allowed by the Technical Specifications due to Low Suction Pressure Trips | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000374/LER-2017-002 | High Pressure Core Spray System Declared Inoperable due to Cooling Water Strainer Backwash Valve Stem-Disc Separation LER 17-002-00 for LaSalle, Unit 2, Regarding High Pressure Core Spray System Declared Inoperable due to Cooling Water Strainer Backwash Valve Stem-Disc Separation | 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | 05000374/LER-2017-003 | High Pressure Core Spray System Inoperable due to Injection Valve Stem-Disc Separation LER 17-003-01 for LaSalle County Station, Unit 2 Regarding High Pressure Core Spray System Inoperable due to Injection Valve Stem-Disc Separation | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000373/LER-2017-003 | Automatic Reactor Scram due to Main Generator Trip on Differential Current During Back-Feed Operations LER 17-003-00 for LaSalle County Station, Unit 1, Regarding Automatic Reactor Scram due to Main Generator Trip on Differential Current During Back-Feed Operations | 10 CFR 50.73(a)(2)(iv)(A), System Actuation | 05000374/LER-2017-004 | Two Main Steam Safety Relief Valves Failed Inservice Lift Inspection Pressure Test LER 17-004-01 for LaSalle, Unit 2, Regarding Two Main Steam Safety Relief Valves Failed Inservice Lift Inspection Pressure Test | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications | 05000373/LER-2017-004 | Secondary Containment Inoperable Due to Interlock Doors Open LER 17-004-00 for LaSalle County, Unit 1, Regarding Secondary Containment Inoperable Due to Interlock Doors Open | 10 CFR 50.73(a)(2)(v)(C), Loss of Safety Function - Release of Radioactive Material 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | 05000373/LER-2017-005 | Manual Reactor Scram Resulting From Feedwater Regulating Valve Failure Causing High Reactor Water Level LER 17-005-00 for LaSalle County, Unit 1, Regarding Manual Reactor Scram Resulting From Feedwater Regulating Valve Failure Causing High Reactor Water Level | 10 CFR 50.73(a)(2)(iv)(A), System Actuation | 05000373/LER-2017-006 | Low Pressure Core Spray Inoperable due to Minimum Flow Valve Failure in Closed Position LER 17-006-00 for LaSalle, Unit 1, Regarding Low Pressure Core Spray Inoperable due to Minimum Flow Valve Failure in Closed Position | 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | 05000373/LER-2017-007 | Low Pressure Core Spray System Inoperable due to Loss of Cooling LER 17-007-00 for LaSalle County Station, Unit 1, Regarding Low Pressure Core Spray System Inoperable due to Loss of Cooling | 10 CFR 50.73(a)(2)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident |
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