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Category:Letter
MONTHYEARML25022A2962025-01-23023 January 2025 Technical Specification Bases Pages ML25023A0392025-01-23023 January 2025 Senior Reactor and Reactor Operator Initial License Examinations L-25-001, Endorsement of Framatomes Requested Review Schedule for Topical Report ANP-10358P, Revision O Increased Burnup for PWRs2025-01-23023 January 2025 Endorsement of Framatomes Requested Review Schedule for Topical Report ANP-10358P, Revision O Increased Burnup for PWRs ML25014A2862025-01-21021 January 2025 Alternative Request to Defer ASME Code Section XI Inservice Inspection Examinations for Pressurizer and Steam Generator Pressure-Retaining Welds and Full Penetration Welded Nozzles IR 05000336/20244032025-01-13013 January 2025 Cyber Security Inspection Report 05000336/2024403 and 05000423/2024403 (Cover Letter Only) ML24365A2032024-12-30030 December 2024 ISFSI - 10 CFR 72.30 Decommissioning Funding Plan ML24351A2422024-12-19019 December 2024 Reactor Coolant System Alloy 600 Inspection Program for License Renewal Commitment No. 15 ML24351A2412024-12-19019 December 2024 Reactor Vessel Internals Inspections Aging Management Program Submittal Related to License Renewal Commitment No. 13 ML24346A2532024-12-12012 December 2024 Correction to Implementation Date for License Amendment No. 291 Regarding Framatome Gaia Fuel IR 05000336/20243012024-12-0606 December 2024 Initial Operator Licensing Examination Report 05000336/2024301 ML24324A0442024-12-0303 December 2024 Issuance of Amendment No. 292 Regarding Adoption of Technical Specification Task Force Traveler TSTF-421 05000336/LER-2024-002, Two Main Steam Safety Valves Failed to Lift within the Acceptance Criteria Resulting in a Condition Prohibited by Technical Specifications2024-11-26026 November 2024 Two Main Steam Safety Valves Failed to Lift within the Acceptance Criteria Resulting in a Condition Prohibited by Technical Specifications 05000423/LER-2024-002, Door Latch Failure Resulted in Loss of Safety Function for Secondary Containment Boundary2024-11-26026 November 2024 Door Latch Failure Resulted in Loss of Safety Function for Secondary Containment Boundary ML24296B2352024-11-19019 November 2024 Issuance of Amendment No. 291 License Amendment to Support the Implementation of Framatome Gaia Fuel (EPID L-2023-LLA-0150) (Non-Proprietary) IR 05000245/20240012024-11-12012 November 2024 Safstor Inspection Report 05000245/2024001 ML24317A2562024-11-12012 November 2024 Core Operating Limits Report, Gycle 30 IR 05000336/20240032024-11-0707 November 2024 Integrated Inspection Report 05000336/2024003 and 05000423/2024003 and Apparent Violation and Independent Spent Fuel Storage Installation Inspection Report 07200008/2024001 ML24289A0152024-10-21021 October 2024 Review of the Fall 2023 Steam Generator Tube Inspection Report 05000423/LER-2024-001, Loss of Safety Function and Condition Prohibited by Technical Specifications for Loss of Secondary Containment Boundary2024-10-14014 October 2024 Loss of Safety Function and Condition Prohibited by Technical Specifications for Loss of Secondary Containment Boundary IR 05000336/20244022024-10-0808 October 2024 Security Baseline Inspection Report 05000336/2024402 and 05000423/2024402 (Cover Letter Only) ML24281A1102024-10-0707 October 2024 Requalification Program Inspection 05000423/LER-2023-006-02, Pressurizer Power Operated Relief Valve Failed to Open During Surveillance Testing Resulting in a Condition Prohibited by Technical Specifications2024-09-26026 September 2024 Pressurizer Power Operated Relief Valve Failed to Open During Surveillance Testing Resulting in a Condition Prohibited by Technical Specifications ML24240A1692024-09-18018 September 2024 Cy 2023 Summary of Decommissioning Trust Fund Status ML24260A1952024-09-16016 September 2024 Response to Request for Additional Information Regarding Proposed Amendment to Support Implementation of Framatome Gaia Fuel ML24260A2192024-09-16016 September 2024 Decommissioning Trust Fund Disbursement - Revision to Previous Thirty-Day Written Notification ML24248A2272024-09-0404 September 2024 Operator Licensing Examination Approval ML24240A1532024-09-0303 September 2024 Summary of Regulatory Audit Supporting the Review of License Amendment Request for Implementation of Framatome Gaia Fuel IR 05000336/20240052024-08-29029 August 2024 Updated Inspection Plan for Millstone Power Station, Units 2 and 3 (Reports 05000336/2024005 and 05000423/2024005 IR 05000336/20240022024-08-13013 August 2024 Integrated Inspection Report 05000336/2024002 and 05000423/2024002 ML24221A2872024-08-0808 August 2024 Independent Spent Fuel Storage Installation (ISFSI) - Submittal of Cask Registration for Spent Fuel Storage IR 05000336/20244412024-08-0606 August 2024 Supplemental Inspection Report 05000336/2024441 and 05000423/2024441 and Follow-Up Assessment Letter (Cover Letter Only) ML24212A0742024-08-0505 August 2024 Request for Withholding Information from Public Disclosure - Millstone Power Station, Unit No. 3, Proposed Alternative Request IR-4-13 to Support Steam Generator Channel Head Drain Modification ML24211A1712024-07-25025 July 2024 Associated Independent Spent Fuels Storage Installation, Revision to Emergency Plan - Report of Change ML24200A1062024-07-22022 July 2024 Information Request for the Cybersecurity Baseline Inspection, Notification to Perform Inspection 05000336/2024403 and 05000423/2024403 IR 05000336/20245012024-07-0101 July 2024 Emergency Preparedness Biennial Exercise Inspection Report 05000336/2024501 and 05000423/2024501 ML24180A0932024-06-28028 June 2024 Readiness for Additional Inspection: EA-23-144 IR 05000336/20240102024-06-26026 June 2024 Biennial Problem Identification and Resolution Inspection Report 05000336/2024010 and 05000423/2024010 ML24178A2422024-06-25025 June 2024 2023 Annual Report of Emergency Core Cooling System (ECCS) Model, Changes Pursuant to the Requirements of 10 CFR 50.46 IR 05000336/20244402024-06-24024 June 2024 Final Significance Determination for Security-Related Greater than Green Finding(S) with Assessment Follow-up; IR 05000336/2024440 and 05000423/2024440 and Notice of Violation(S), NRC Investigation Rpt 1-2024-001 (Cvr Ltr Only) ML24281A2072024-06-20020 June 2024 Update to the Final Safety Analysis Report, Revision 37 (Redacted Version) ML24177A2792024-06-20020 June 2024 Preparation and Scheduling of Operator Licensing Examinations ML24280A0012024-06-20020 June 2024 Update to the Final Safety Analysis Report (Redacted Version) ML24176A1782024-06-20020 June 2024 Update to the Final Safety Analysis Report ML24176A2622024-06-20020 June 2024 Update to the Final Safety Analysis Report, Revision 37 ML24170B0532024-06-10010 June 2024 DOM-NAF-2-P/NP-A, Revision 0.5, Reactor Core Thermal-Hydraulics Using the VIPRE-D Computer Code 05000336/LER-2024-001, Control Room Air Conditioning Unit Inoperable Due to Refrigerant Overcharge Resulting in a Condition Prohibited by Technical Specifications2024-06-10010 June 2024 Control Room Air Conditioning Unit Inoperable Due to Refrigerant Overcharge Resulting in a Condition Prohibited by Technical Specifications ML24170A7832024-06-0606 June 2024 ISFSI, Virgil C. Summer, Unit 1, and ISFSI, North Anna, Units 1 & 2, and ISFSI, Surry, Units 1 & 2, and ISFSI - Submittal of Revision 36 of the Quality Assurance Topical Report ML24165A1292024-06-0505 June 2024 ISFSI, 10 CFR 50.59 Annual Change Report for 2023 Annual Regulatory Commitment Change Report for 2023 ML24128A2772024-06-0404 June 2024 Issuance of Amendment No. 290 to Revise TSs for Reactor Core Safety Limits, Fuel Assemblies, and Core Operating Limits Report for Use of Framatome Gaia Fuel (EPID L-2023-LLA-0074) (Non-Proprietary) ML24151A6482024-06-0303 June 2024 Changes in Reactor Decommissioning Branch Project Management Assignments for Some Decommissioning Facilities 2025-01-23
[Table view] Category:Licensee Event Report (LER)
MONTHYEAR05000423/LER-2024-002, Door Latch Failure Resulted in Loss of Safety Function for Secondary Containment Boundary2024-11-26026 November 2024 Door Latch Failure Resulted in Loss of Safety Function for Secondary Containment Boundary 05000336/LER-2024-002, Two Main Steam Safety Valves Failed to Lift within the Acceptance Criteria Resulting in a Condition Prohibited by Technical Specifications2024-11-26026 November 2024 Two Main Steam Safety Valves Failed to Lift within the Acceptance Criteria Resulting in a Condition Prohibited by Technical Specifications 05000423/LER-2024-001, Loss of Safety Function and Condition Prohibited by Technical Specifications for Loss of Secondary Containment Boundary2024-10-14014 October 2024 Loss of Safety Function and Condition Prohibited by Technical Specifications for Loss of Secondary Containment Boundary 05000423/LER-2023-006-02, Pressurizer Power Operated Relief Valve Failed to Open During Surveillance Testing Resulting in a Condition Prohibited by Technical Specifications2024-09-26026 September 2024 Pressurizer Power Operated Relief Valve Failed to Open During Surveillance Testing Resulting in a Condition Prohibited by Technical Specifications 05000336/LER-2024-001, Control Room Air Conditioning Unit Inoperable Due to Refrigerant Overcharge Resulting in a Condition Prohibited by Technical Specifications2024-06-10010 June 2024 Control Room Air Conditioning Unit Inoperable Due to Refrigerant Overcharge Resulting in a Condition Prohibited by Technical Specifications 05000423/LER-2023-006-01, Pressurizer Power Operated Relief Valve Failed to Open During Surveillance Testing Resulting in a Condition Prohibited by Technical Specifications2024-05-20020 May 2024 Pressurizer Power Operated Relief Valve Failed to Open During Surveillance Testing Resulting in a Condition Prohibited by Technical Specifications 05000423/LER-2023-006, Pressurizer Power Operated Relief Valve Failed to Stroke Open During Surveillance Testing Resulting in a Condition Prohibited by Technical Specifications2024-05-0202 May 2024 Pressurizer Power Operated Relief Valve Failed to Stroke Open During Surveillance Testing Resulting in a Condition Prohibited by Technical Specifications 05000423/LER-2023-005, Oil Leakage from C RSS Pump Motor Challenged Meeting Its Mission Time Resulting in a Condition Prohibited by Technical Specifications2024-02-0808 February 2024 Oil Leakage from C RSS Pump Motor Challenged Meeting Its Mission Time Resulting in a Condition Prohibited by Technical Specifications 05000423/LER-2023-004, For Millstone Power Station, Unit 3 Regarding Reactor Coolant System Pressure Isolation Valves Operational Leakage Exceeded the Acceptance Criteria Resulting in a Condition Prohibited by Technical Specifications2023-12-19019 December 2023 For Millstone Power Station, Unit 3 Regarding Reactor Coolant System Pressure Isolation Valves Operational Leakage Exceeded the Acceptance Criteria Resulting in a Condition Prohibited by Technical Specifications 05000423/LER-2023-003, RCS Temperature Detector Exceeded Time Response Acceptance Criteria Resulting in a Condition Prohibited by Technical Specifications2023-12-0808 December 2023 RCS Temperature Detector Exceeded Time Response Acceptance Criteria Resulting in a Condition Prohibited by Technical Specifications 05000423/LER-2023-002, Auxiliary Feedwater Control Valve Failure Resulting in a Condition Prohibited by Technical Specifications2023-11-30030 November 2023 Auxiliary Feedwater Control Valve Failure Resulting in a Condition Prohibited by Technical Specifications 05000336/LER-2023-002, Failed Check Valve Resulted in an Unanalyzed Condition2023-08-31031 August 2023 Failed Check Valve Resulted in an Unanalyzed Condition 05000423/LER-2023-001, Automatic Reactor Trip Due to Main Generator Output Breaker Ground Fault2023-07-27027 July 2023 Automatic Reactor Trip Due to Main Generator Output Breaker Ground Fault 05000336/LER-2023-001, For Millstone, Unit 2, Structural Integrity of a Train Service Water Header Piping Could Not Be Demonstrated Causing the Unit to Operate in a Condition Prohibited by Technical Specifications2023-07-0707 July 2023 For Millstone, Unit 2, Structural Integrity of a Train Service Water Header Piping Could Not Be Demonstrated Causing the Unit to Operate in a Condition Prohibited by Technical Specifications 05000423/LER-2022-002, Two Main Steam Safety Valves Installed in Wring Location Resulting in Failure to Lift within the Technical Specification Acceptance Criteria2022-05-31031 May 2022 Two Main Steam Safety Valves Installed in Wring Location Resulting in Failure to Lift within the Technical Specification Acceptance Criteria 05000423/LER-2022-001, Emergency Core Cooling and Reactor Plant Component Cooling Water Systems Inoperable for Time Greater than Allowed by Technical Specifications2022-03-24024 March 2022 Emergency Core Cooling and Reactor Plant Component Cooling Water Systems Inoperable for Time Greater than Allowed by Technical Specifications 05000336/LER-2022-001, Structural Integrity of Reactor Building Component Cooling Water Cracked Threaded Fitting Could Not Be Established Resulting in System Inoperable Longer than Allowed by Technical Specifications2022-03-18018 March 2022 Structural Integrity of Reactor Building Component Cooling Water Cracked Threaded Fitting Could Not Be Established Resulting in System Inoperable Longer than Allowed by Technical Specifications 05000336/LER-2021-002, Failed Check Valve Resulting in Unnalyzed and Operation Prohibited by Technical Specifications2022-01-0505 January 2022 Failed Check Valve Resulting in Unnalyzed and Operation Prohibited by Technical Specifications 05000336/LER-2021-001, Incorrectly Placed Spent Fuel Assemblies in Unit 2 Spent Fuel Pool2021-09-23023 September 2021 Incorrectly Placed Spent Fuel Assemblies in Unit 2 Spent Fuel Pool 05000423/LER-2020-005, Loss of Safety Function - Secondary Containment2020-11-19019 November 2020 Loss of Safety Function - Secondary Containment 05000423/LER-2020-002, 3, Automatic Reactor Trip Due to Main Generator Ground Fault2020-05-28028 May 2020 3, Automatic Reactor Trip Due to Main Generator Ground Fault 05000423/LER-2020-001, Technical Specification Allowed Outage Time Exceeded by Accident Monitoring Instrument2020-03-0505 March 2020 Technical Specification Allowed Outage Time Exceeded by Accident Monitoring Instrument 05000336/LER-2019-001, Manual Reactor Trip Due to Loss of the a Steam Generator Feed Pump2020-02-19019 February 2020 Manual Reactor Trip Due to Loss of the a Steam Generator Feed Pump 05000423/LER-2019-001, Regarding Plant Shutdown Required by Technical Specifications, Emergency Diesel Generator Exceeded Allowed Outage Time2020-02-13013 February 2020 Regarding Plant Shutdown Required by Technical Specifications, Emergency Diesel Generator Exceeded Allowed Outage Time 05000336/LER-2018-001, Regarding Loss of Both Trains of Control Room Emergency Ventilation Resulting in the Loss of Safety Function2018-12-19019 December 2018 Regarding Loss of Both Trains of Control Room Emergency Ventilation Resulting in the Loss of Safety Function 05000423/LER-2017-001, Regarding Loss of Safety Function - Secondary Containment2017-03-20020 March 2017 Regarding Loss of Safety Function - Secondary Containment 05000336/LER-2016-002, Regarding Manual Reactor Trip Due Loss of Two Circulating Water Pumps2016-09-20020 September 2016 Regarding Manual Reactor Trip Due Loss of Two Circulating Water Pumps 05000423/LER-2016-005, Technical Specification Required Shutdown and Manual Reactor Trip Due to Steam Generator Level Oscillation2016-08-0909 August 2016 Technical Specification Required Shutdown and Manual Reactor Trip Due to Steam Generator Level Oscillation 05000423/LER-2016-004, Manual Reactor Trip Due to Low Hydrogen Gas Pressure in Main Generator2016-07-13013 July 2016 Manual Reactor Trip Due to Low Hydrogen Gas Pressure in Main Generator 05000336/LER-2016-001, Turbine Driven Auxiliary Feedwater Pump Room HELB Door Left Open2016-06-27027 June 2016 Turbine Driven Auxiliary Feedwater Pump Room HELB Door Left Open 05000423/LER-2016-003, Regarding Loss of Safety Function-Supplementary Leak Collection and Release System2016-06-0808 June 2016 Regarding Loss of Safety Function-Supplementary Leak Collection and Release System 05000423/LER-2016-002, Regarding Feedwater Isolation Signal Defeated Due to Wiring Error2016-03-23023 March 2016 Regarding Feedwater Isolation Signal Defeated Due to Wiring Error 05000423/LER-2016-001, Regarding Automatic Reactor Trip on Reactor Coolant System Low Flow Due to Loss of B Reactor Coolant Pump2016-03-16016 March 2016 Regarding Automatic Reactor Trip on Reactor Coolant System Low Flow Due to Loss of B Reactor Coolant Pump 05000336/LER-2015-003, Regarding Valid Actuation of the Reactor Protection System2016-01-0707 January 2016 Regarding Valid Actuation of the Reactor Protection System 05000336/LER-2015-002, Regarding Degraded Emergency Core Cooling System Check Valve2015-08-10010 August 2015 Regarding Degraded Emergency Core Cooling System Check Valve 05000336/LER-2015-001, Regarding Historical Oil Leakage from C RBCCW Pump Bearings Challenged Meeting Mission Time2015-06-16016 June 2015 Regarding Historical Oil Leakage from C RBCCW Pump Bearings Challenged Meeting Mission Time 05000423/LER-2015-001, Regarding Unlatched Dual Train HELB Door Results in Potential Loss of Safety Function2015-04-20020 April 2015 Regarding Unlatched Dual Train HELB Door Results in Potential Loss of Safety Function 05000423/LER-2014-004, Regarding Unlatched Dual Train HELB Door Results in Potential Loss of Safety Function2015-02-0909 February 2015 Regarding Unlatched Dual Train HELB Door Results in Potential Loss of Safety Function 05000336/LER-2014-007, Regarding Completion of Plant Shutdown Required by Technical Specifications2014-09-24024 September 2014 Regarding Completion of Plant Shutdown Required by Technical Specifications 05000336/LER-2014-006, Regarding Millstone Power Station Dual Unit Reactor Trip on Loss of Offsite Power2014-07-24024 July 2014 Regarding Millstone Power Station Dual Unit Reactor Trip on Loss of Offsite Power 05000336/LER-2014-005, Regarding Train a Containment Spray Inoperable Due to Gas Voids2014-07-16016 July 2014 Regarding Train a Containment Spray Inoperable Due to Gas Voids 05000423/LER-2014-003, Regarding Turbine Driven Auxiliary Feedwater Pump Operability Impacted by Incorrect Bearing2014-06-30030 June 2014 Regarding Turbine Driven Auxiliary Feedwater Pump Operability Impacted by Incorrect Bearing 05000336/LER-2014-004, Regarding Foreign Material Found in a Motor Lead Rendered a Motor Driven Auxiliary Feedwater Pump Inoperable2014-06-0909 June 2014 Regarding Foreign Material Found in a Motor Lead Rendered a Motor Driven Auxiliary Feedwater Pump Inoperable 05000336/LER-2014-003, Regarding Loss of Safety Function Due to Inoperable Enclosure Building2014-06-0202 June 2014 Regarding Loss of Safety Function Due to Inoperable Enclosure Building 05000336/LER-2014-002, 2 Regarding DC Circuit Hot Shorts2014-05-0505 May 2014 2 Regarding DC Circuit Hot Shorts 05000423/LER-2014-002, Regarding DC Circuit Hot Shorts2014-05-0505 May 2014 Regarding DC Circuit Hot Shorts 05000336/LER-2014-001, Regarding Completion of Plant Shutdown Required by Technical Specifications2014-03-31031 March 2014 Regarding Completion of Plant Shutdown Required by Technical Specifications 05000423/LER-2014-001, Limiting Condition for Operation Exceeded Upon Approval of Enforcement Discretion2014-03-17017 March 2014 Limiting Condition for Operation Exceeded Upon Approval of Enforcement Discretion 05000423/LER-2013-009, Regarding Secondary Containment Boundary Breach Could Have Prevented Safety Function2014-01-15015 January 2014 Regarding Secondary Containment Boundary Breach Could Have Prevented Safety Function 05000336/LER-2013-004, Unit 2 Regarding Reactor Trip While Backwashing D Waterbox2013-12-19019 December 2013 Unit 2 Regarding Reactor Trip While Backwashing D Waterbox 2024-09-26
[Table view] |
LER-2022-001, Emergency Core Cooling and Reactor Plant Component Cooling Water Systems Inoperable for Time Greater than Allowed by Technical Specifications |
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text
Dominion Energy Nuclear Connecticut, Inc.
Millstone Power Station 314 Rope Ferry Road, *waterford, CT 06385 Dominion Energy.com, U. S. Nuclear Regulatory Commission Attention: Document Control 'Desk Washington, DC 20555
MILLSTONE POWER STATION UNIT 3 LICENSEE EVENT REPORT 2022-001-00
~
Dominion
~
Energy
~-
Serial No.:
22-069 MPS Lie/DB RO Docket No.: 50-423 License No.: NPF-49
- MAR 2 4 2022 EMERGENCY CORE COOLING AND REACTOR PLANT COMPONENT COOLING WATER SYSTEMS INOPERABLE FOR TIME GREATER* THAN ALLOWED BY TECHNICAL SPECIFICATIONS This letter forwards Licensee Event Report (LER) 2022-001-00, documenting a condition that occurred at Millstone Power Station Unit 3 (MPS3), on January 26, 2022, when MPS3 exceeded a Technical Specification required shutdown action statement..During a telephone conversation at 8:30 AM EST on January 26, 2022, the NRG approved a verbal request from DENG that a Notice of Enforcement Discretion (NOED) be issued allowing continued operation for an additional 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> beyond the expiration of the TS action statement. This LER is being submitted pursuant to 10 GFR 50.73(a)(2)(i)(B) as operation or condition prohibited by Technici:1I Specifications.
There are no regulatory commitments contained in this letter or its enclosure. Should you have any questions, please contact Mr. Dean E. Rowe at (860) 444-5292.
Sincerely, W\\~CT_~c--
Michael J. O'Connor Site Vice President - Millstone
Enclosure:
LER 423/2022-001-00
f:
cc:
U.S. Nuclear Regulatory Commission Region I 2100 Renaissance Blvd.
Suite 100 King of Prussia, PA 19406-2713 R.V. Guzman NRC Senior Project Manager Millstone Units 2 and 3 U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 08 C-2
'Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station Serial No.22-069 Docket No. 50-423 Licensee Event Report 2022-001-00 Page 2 of 2
ATTACHMENT Serial No.22-069 Docket No. 50-423 Licensee Event Report 2022-001-00 LICENSEE EVENT REPORT 2022-001-00 EMERGENCY CORE COOLING AND REACTOR PLANT COMPONENT COOLING WATER SYSTEMS INOPERABLE FOR TIME GREATER THAN ALLOWED BY TECHNICAL SPECIFICATIONS MILLSTONE POWER STATION UNIT 3 DOMINION ENERGY NUCLEAR CONNECTICUT, INC.
NRG FORM 366 (08-2020)
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 08/31/2023 LICENSEE EVENT REPORT (LER)
(See Page 3 for required number of digits/characters for each block)
(See NUREG-1022, R.3 for instruction and guidance for completing this form
!:illi:r//www.nrc.gov/re ading-rm/d oc-co I lectio ns/n u reg s/staff/sr1 022/r3D
- 3. Page Millstone Power Station Unit 3 05000 423 1 OF 4
- 4. Title Emergency Core Cooling and Reactor Plant Component Cooling Water Systems Inoperable For Time Greater Than Allowed by Technical Specifications
- 5. Event Date
- 6. LER Number
- 7. Report Date
- 8. Other Facilities Involved Month Day Year Year Sequential Revision Month Day Year Facility Name Number No.
Docket Number 05000 01 26 2022 2022 -
001 -
00 03 24 2022 Facility Name Docket Number 05000
- 9. Operating Mode 110. Power Level 1
100
Abstract
On January 23, 2022, at 1118 hours0.0129 days <br />0.311 hours <br />0.00185 weeks <br />4.25399e-4 months <br />, the 'B' train Charging Pump and Reactor Plant Component Cooling Water (RPCCW)
Pump Area Exhaust Fan, 3HVR*FN138, failed. This resulted in tripping its supply breaker, 32-1W(F4M), fire alarms, Control Room alarms, and an auto start of the standby fan. Because these fans support operability of the Emergency Core Cooling Systems (ECCS) and RPCCW systems, 72-hour Technical Specification Action Statements (TSAS) were entered for one ECCS subsystem and one RPCCW safety loop being inoperable. When it became evident repairs could not be completed within the Technical Specification Allowetj Outage Time (TS AOT), a request was made, and approved, for a Notice Of Enforcement Discretion for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> beyond the TS AOT to provide time to restore the fan and operability of ECCS and RPCCW. ECCS and RPCCW were inoperable for a total of 105 hours0.00122 days <br />0.0292 hours <br />1.736111e-4 weeks <br />3.99525e-5 months <br /> and 32 minutes. The cause of the fan failure was a failed motor bearing. The fan was repaired and restored to operable status on January 27, 2022 at 2050 hours0.0237 days <br />0.569 hours <br />0.00339 weeks <br />7.80025e-4 months <br />.
This condition is being reported pursuant to 1 0CFR50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications.
1. EVENT DESCRIPTION
On January 23, 2022, at 1118 hours0.0129 days <br />0.311 hours <br />0.00185 weeks <br />4.25399e-4 months <br />, the 'B' train Charging Pump and Reactor Plant Component Cooling Water (RPCCW)
Pump Area Exhaust Fan, 3HVR*FN13B, failed. This resulted in tripping its supply breaker, 32-1W(F4M), fire alarms, Control Room alarms, and an auto start of the standby fan. This fan provides a support function for the Charging Pumps and RPCCW Pumps, as well as supporting operation of the Auxiliary Building Filter system and Supplemental Leak Collection and Release System (SLCRS). As a result of the fan tripping, Operations personnel entered the following Technical Specification Action Statements (TSAS):
- TSAS 3.5.2.a for one Emergency Core Cooling System (ECCS) subsystem inoperable, which requires the inoperable subsystem to be restored to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, or the unit placed in HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
- TSAS 3.7.3 for one RPCCW safety loop inoperable, which requires the inoperable safety loop to be restored to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, or the unit placed in HOT STANDBY within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
- TSAS 3.6.6.1 for one SLCRS system inoperable, which requires the inoperable system to be restored within 7 days, or the unit placed in HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
- TSAS 3.7.9 for one Auxiliary Building Filter system inoperable, which requires the inoperable system to be restored within 7 days, or the unit placed in HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
Millstone Maintenance inspected the fan and found that the motor shaft was bent, causing the fan blades to contact the housing. After the failure was identified, repair activities proceeded on a continuous basis with the goal of completing the repairs and validating operability of the fan prior to expiration of the 72-hour Allowed Outage time (AOT) of TSAS 3.5.2.a and 3.7.3_ However, as corrective maintenance activities to replace the fan motor and fan hub assembly progressed, completion of the repairs was forecasted to extend beyond the original 72-hour AOT. Therefore, on January 26, 2022, at approximately 0830 hours0.00961 days <br />0.231 hours <br />0.00137 weeks <br />3.15815e-4 months <br />, Dominion Energy Nuclear Connecticut (DENG) informed the Nuclear Regulatory Commission (NRC) of the need for a Notice Of Enforcement Discretion (NOED) from the requirements of TS 3.5.2 and 3.7.3 for a period of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to avoid an unnecessary shutdown while repairs were completed. The NOED request was verbally approved by the NRC on January 26, 2022, at approximately 1034 hours0.012 days <br />0.287 hours <br />0.00171 weeks <br />3.93437e-4 months <br />. On January 27, 2022, at 2050 hours0.0237 days <br />0.569 hours <br />0.00339 weeks <br />7.80025e-4 months <br />, corrective maintenance and post-maintenance testing of the fan was completed satisfactorily, the TSASs were exited, and the period of Notice Of Enforcement Discretion exited.
One ECCS subsystem and one RPCCW safety loop were inoperable for a total of 105 hours0.00122 days <br />0.0292 hours <br />1.736111e-4 weeks <br />3.99525e-5 months <br /> and 32 minutes, which exceeds the 72-hour AOT of TSAS 3.5.2.a and 3.7.3. Therefore, this event is being reported in accordance with 10CFR50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications.
2.CAUSE
Investigation has determined that the fan failure was caused by a motor bearing failure.
The failed bearing is manufactured by FAFNIR and its model number is 314KDD BEARING.
3. ASSESSMENT OF SAFETY CONSEQUENCES
MPS3 Charging Pump and RPCCW Pump Area exhaust fan 3HVR*FN13B is safety related but does not have any direct TS requirements. However, the fan does support the charging pump and RPCCW pump and heat exchangers, as well as the Auxiliary Building Filter and SLCRS systems, which are TS equipment. Therefore, this fan affects the TS for ECCS, RPCCW, SLCRS, and Auxiliary Building Filter System.
The Charging Pump and RPCCW Pump Area supply and exhaust fans are part of the Auxiliary Building Filter System (ABFS). The fans are redundant, 100% capacity each. The fans provide an environment suitable for personnel access and equipment operation. It also controls and minimizes the potential for spread of airborne radioactive material within the building.
In the event of a safety injection signal (SIS) or a containment depressurization actuation (CDA) signal, the auxiliary building general area ventilation is shutdown; the building outlet isolation dampers close; the Charging Pump and RPCCW Pump Area ventilation exhaust dampers close; the auxiliary building filter unit inlet and outlet dampers open; the filter exhaust fans start automatically; and the Charging Pump and RPCCW Pump Area supply and exhaust fans continue to operate venting through the turbine building stack via the Auxiliary Building Filter System (ABFS). An SIS signal also automatically starts operation of SLCRS. During accident conditions, the ABFS and SLCRS operate together to bring the secondary containment enclosure, auxiliary building, engineered safety features (ESF) building, hydrogen re-combiner building, and the main steam valve building to negative pressure within 120 seconds.
Operability of 3HVR*FN13B is required by MPS3 procedures in recognition of the potential for higher (more adverse) ambient temperatures in the area of the charging and RPCCW pumps if the exhaust fan is lost, and also as the suction air source for the ABFS. However, the fan is not included as a TS or Technical Requirements Manual (TRM) required component.
Adequate heat removal has been demonstrated with an Ultimate Heat Sink temperature up to 80 °F (TS 3/4.7.5). During the period 3HVR*FN13B was inoperable, the service water temperature was approximately 41.8 °F and outside air temperatures (winter air temperatures) ensure delivered air is on the lower side of the allowed range. These service water and outside air temperatures provided substantial margin for ensuring pump cooling capacity.
3HVR*FN13A was in service providing the necessary ventilation for normal operation and as the initial condition for accident scenarios. For 3HVR*FN 13B being out of service to have had an adverse effect on an analyzed transient, an event initiator would need to be combined with a failure specifically in the 'A' train (either 3HVR*FN13A. 'A' train Emergency Diesel Generator or 4160 Volt Power Supply). Margin in the current FSAR dose consequence analyses to the 10 CFR 50.67 Total Effective Dose Equivalent (TEDE) Limits is shown in the table below. This margin is available to offset the potential for'a reduction in the SLCRS drawdown capability following a potential loss of both trains of ABFS.
However, all forced flow releases would remain filtered by the SLCRS. During the time spent in the TSAS, including the period of enforcement discretion, the opposite train of ABFS was maintained in service. Therefore, safety margins were maintained.
Dose Location EAB LPZ Control Room The System Operating Procedure for Auxiliary Building Emergency Ventilation and Exhaust (OP 3314J) provides instruction for the installation and operation of Portable Emergency Ventilation Fan, 3HVR-FN18, and a portable generator. Performance of this procedure satisfies requirements of TRM 7.4.1, Fire Related Safe Shutdown Components.
This procedure is the contingency plan in the event of failure of the charging and RPCCW pump area ventilation system.
Providing emergency ventilation to the Auxiliary Building in accordance with OP 3314J is modeled as a recovery action given failure of the Charging/RPCCW area ventilation system in the quantitative risk assessment.
The ECCS and RPCCW systems were expected to maintain their ability to perform their safety functions during the period of enforcement discretion. No other structures, systems, or components (SSCs) were affected during the period of enforcement discretion and no limits were imposed on any SSC that hindered their ability to perform their specified function. The independence of the physical barriers to radiological releases were not degraded during the period of enforcement discretion. The planned activities on 3HVR*FN138 did not impact fuel cladding, RCS or Containment integrity. No other SSCs were affected by the proposed period of enforcement discretion, and therefore no limits were imposed on any SSC in performing their specified safety function.
Based on the above, there were no safety consequences associated with 3HVR*FN13B being inoperable for a period of approximately 33.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> beyond the TS AOT.
4. CORRECTIVE ACTIONS
The damaged motor was replaced with a spare motor from the warehouse. A like-for-like fan hub and blade assembly was used to replace the damaged hub and blade assembly.
Additional corrective actions will be taken in accordance with the station Corrective Action Program.
5. PREVIOUS OCCURRENCES
There have been no similar events of a fan being inoperable for longer than the TS AOT at Millstone Power Station Unit 3 in the past three years.
- 6. ENERGY INDUSTRY IDENTIFICATION SYSTEM (EIIS) CODES VF - Auxiliary Building Environmental Control System FAN - Fan Page 4
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