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Category:Letter
MONTHYEARML25014A3082025-01-21021 January 2025 Transmittal Letter for VC Summer SE for SLRA Review ML25020A0342025-01-20020 January 2025 Special Report 2025-002 for Virgil C. Summer Nuclear Station, Unit 1, Inoperable Radiation Monitoring Instrumentation Channel ML25007A2342025-01-17017 January 2025 Limited Scope Aging Management Audit Report Regarding the Subsequent License Renewal Application Review ML25021A0612025-01-16016 January 2025 Special Report 2025-001 for Virgil Summer Nuclear Station, Unit 1, Inoperable Loose-Part Monitoring System Channel ML24344A1902024-12-23023 December 2024 Summary of Safety Inspection of the Service Water Reservoir Dam (CAC Nos. 001370/05000395; EPID L-2017-LNS-0015) (Nonproprietary Cover Letter) ML24340A1572024-12-0404 December 2024 Annual Commitment Change Summary Report ML24221A0602024-11-25025 November 2024 Staff Assessment of Updated Seismic Hazards Following the NRC Process for the Ongoing Assessment of Natural Hazards Information 05000395/LER-2024-003, Common Cause Inoperability of Engineered Safety Features2024-11-18018 November 2024 Common Cause Inoperability of Engineered Safety Features ML24278A2832024-11-0707 November 2024 Letter to E. Carr Environmental Impact Statement Scoping Summary Report for Virgil C. Summer Nuclear Station Unit 1 IR 05000395/20240032024-11-0606 November 2024 – Integrated Inspection Report 05000395/2024003 ML24305A1302024-10-31031 October 2024 Submittal of 30 Day Report Per 10 CFR 26.719(c) Blind Performance Testing ML24308A0052024-10-28028 October 2024 10-28-24 NRC V.C. Summer Nuclear Station SLR Cherokee Nation Letter to USNRC ML24308A0062024-10-25025 October 2024 Subsequent License Renewal Application Area of Potential Effect (Ape) Clarification Fairfield County, South Carolina SHPO Project No. 22-EJ0147 ML24302A1442024-10-24024 October 2024 Update to Subsequent License Renewal Application (SLRA) Supplement 4 and Requested Information Formation in Response to Limited Aging Management Audit ML24250A0782024-10-22022 October 2024 Relief Request RR-5-V1 Regarding Service Water Return Header Check Valves ML24255A3152024-10-22022 October 2024 Relief Request RR-5-V2 Regarding Pressure Isolation Valves ML24256A2322024-10-22022 October 2024 Relief Request RR-5-P1 Charging/Safety Injection Pumps 05000395/LER-2024-002, Loss of Control Room Emergency Filtration System2024-10-15015 October 2024 Loss of Control Room Emergency Filtration System ML24290A1052024-10-0707 October 2024 Core Operating Limits Report VCSNS Unit 1 Cycle 29, Revision 0 IR 05000395/20244042024-09-26026 September 2024 Cyber Security Inspection Report 05000395-2024404 - Public ML24274A1942024-09-26026 September 2024 (Vcsns), Unit 1 Subsequent License Renewal Application (SLRA) First 10 CFR 54.21(b) Annual Amendment ML24221A2112024-09-23023 September 2024 Clarification Regarding Area of Potential Effect for the Subsequent Operating License Renewal for Virgil C. Summer Nuclear Station Fairfield County, South Carolina (SHPO Project Number: 22-EJ0147) (Docket Number: 50-395) ML24267A0542024-09-23023 September 2024 Clarification Regarding Area of Potential Effect for the Subsequent Operating License Renewal for Virgil C. Summer Nuclear Station Fairfield County, South Carolina (SHPO Project Number: 22-EJ0147) (Docket Number: 50-395) ML24267A0552024-09-23023 September 2024 Clarification Regarding Area of Potential Effect for the Subsequent Operating License Renewal for Virgil C. Summer Nuclear Station Fairfield County, South Carolina (SHPO Project Number: 22-EJ0147) (Docket Number: 50-395) ML24267A0592024-09-23023 September 2024 Clarification Regarding Area of Potential Effect for the Subsequent Operating License Renewal for Virgil C. Summer Nuclear Station Fairfield County, South Carolina (SHPO Project Number: 22-EJ0147) (Docket Number: 50-395) ML24267A0642024-09-23023 September 2024 Clarification Regarding Area of Potential Effect for the Subsequent Operating License Renewal for Virgil C. Summer Nuclear Station Fairfield County, South Carolina (SHPO Project Number: 22-EJ0147) (Docket Number: 50-395) IR 05000395/20244022024-09-10010 September 2024 Security Baseline Inspection Report 05000395/2024402 IR 05000395/20240052024-08-22022 August 2024 Updated Inspection Plan for Virgil C. Summer Nuclear Station - Report 05000395/2024005 ML24190A4012024-08-19019 August 2024 Request for Withholding Information from Public Disclosure Regarding the Subsequent License Renewal Application - Dominion Energy Letter Dated May 30, 2024 IR 05000395/20240022024-08-12012 August 2024 Integrated Inspection Report 05000395/2024002 ML24180A0062024-08-0505 August 2024 Issuance of Amendment No. 227 to Modify Technical Specification 3.8.3.1 to Increase Completion Time for 120-Volt A.C. Vital Busses ML24218A3002024-08-0101 August 2024 Environmental Review Response to NRC Requests for Additional Information and Response to NRC Requests for Confirmation of Information Set 1 ML24158A3882024-07-31031 July 2024 Issuance of Amendment No. 226 to Change Emergency Plan Staff Augmentation Times and Relocate Emergency Operations Facility ML24162A3292024-07-0505 July 2024 Letter to E Carr - V.C. Summer Unit 1 - Summary of the May 2024 Audit Regarding the Environmental Review of the Subsequent License Renewal Application IR 05000395/20240112024-06-26026 June 2024 – Comprehensive Engineering Team Inspection Report 05000395/2024011 ML24185A1902024-06-25025 June 2024 Submittal of Updated Final Safety Analysis Report, Revision 24 ML24177A1382024-06-25025 June 2024 Aging Management Audit Report- VC Summer, Unit 1 - Subsequent License Renewal Application ML24178A1192024-06-25025 June 2024 Update to License Amendment Request- Inverter Allowed Outage Time (AOT) Extension 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 ML24177A2792024-06-20020 June 2024 Preparation and Scheduling of Operator Licensing Examinations ML24171A0152024-06-17017 June 2024 Update to Subsequent License Renewal Application (SLRA) Response to NRC Request for Additional Information Set 2 Safety Review 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 ML24157A3352024-06-0606 June 2024 – Notification of an NRC Cybersecurity Baseline Inspection (NRC Inspection Report 05000395-2024404 and Request for Information ML24155A2042024-05-31031 May 2024 Proposed Alternative Request RR-24-123, Containment Unbonded Post-Tensioning System Inservice Inspection Requirements ML24155A1462024-05-30030 May 2024 Update to Subsequent License Renewal Application (SLRA) -Response to NRC Request for Additional Information Set 1 Response to NRC Request for Confirmation of Information Set 1 and Supplement 3 ML24143A1792024-05-22022 May 2024 Special Report 2024-001-01 for Virgil C. Summer Nuclear Station (Vcsns), Unit 1, Waste Gas System Inoperability ML24141A2822024-05-20020 May 2024 (Vcsns), Unit 1 - License Amendment Request - Emergency Response Organization (ERO) Augmentation Time Change, Emergency Operations Facility Relocation and Other Emergency Plan Changes IR 05000395/20240012024-05-10010 May 2024 Integrated Inspection Report 05000395/2024001 ML24129A2002024-05-0606 May 2024 Update to Subsequent License Renewal Application, Supplement 2 IR 05000395/20240402024-05-0101 May 2024 95001 Supplemental Inspection Report 05000395/2024040 and Follow-Up Assessment Letter 2025-01-21
[Table view] Category:Licensee Event Report (LER)
MONTHYEAR05000395/LER-2024-003, Common Cause Inoperability of Engineered Safety Features2024-11-18018 November 2024 Common Cause Inoperability of Engineered Safety Features 05000395/LER-2024-002, Loss of Control Room Emergency Filtration System2024-10-15015 October 2024 Loss of Control Room Emergency Filtration System 05000395/LER-2024-001, (Vcsns), Unit 1, Automatic Actuation of B Emergency Diesel Generator2024-04-17017 April 2024 (Vcsns), Unit 1, Automatic Actuation of B Emergency Diesel Generator 05000395/LER-2023-001, Manual Reactor Trip Due to Loss of Main Feedwater Pump2023-05-30030 May 2023 Manual Reactor Trip Due to Loss of Main Feedwater Pump 05000395/LER-2022-001-01, (Vcsn), Unit 1, Manual Reactor Trip Due to Main Transformer Fault2022-12-15015 December 2022 (Vcsn), Unit 1, Manual Reactor Trip Due to Main Transformer Fault 05000395/LER-2022-002-01, Condition Prohibited by Technical Specifications: Inoperable B Emergency Diesel Generator2022-12-0808 December 2022 Condition Prohibited by Technical Specifications: Inoperable B Emergency Diesel Generator 05000395/LER-2022-002, (Vcsns), Unit 1, Potential Condition Prohibited by Technical Specification 3.8.1.12022-04-11011 April 2022 (Vcsns), Unit 1, Potential Condition Prohibited by Technical Specification 3.8.1.1 05000395/LER-2021-001-01, Condition Prohibited by Technical Specifications2022-02-0808 February 2022 Condition Prohibited by Technical Specifications 05000395/LER-2021-001, (Vcsns), Unit 1, Condition Prohibited by Technical Specifications2021-08-26026 August 2021 (Vcsns), Unit 1, Condition Prohibited by Technical Specifications 05000395/LER-2019-003-01, (Vcsns), Completion of a Technical Specification Required for Plant Shutdown2020-04-0202 April 2020 (Vcsns), Completion of a Technical Specification Required for Plant Shutdown 05000395/LER-2019-004, 4-00 for Virgil C. Summer Nuclear Station (Vcsns), Unit 1, Condition Prohibited by Technical Specification 3.6.1.12020-01-17017 January 2020 4-00 for Virgil C. Summer Nuclear Station (Vcsns), Unit 1, Condition Prohibited by Technical Specification 3.6.1.1 05000395/LER-2019-003, Completion of a Technical Specification Required Plant Shutdown2020-01-0303 January 2020 Completion of a Technical Specification Required Plant Shutdown 05000395/LER-2019-002, Regarding Condition Prohibited by Technical Specification 3.6.42019-10-0909 October 2019 Regarding Condition Prohibited by Technical Specification 3.6.4 05000395/LER-2019-001-01, Regarding Condition Prohibited by Technical Specification 3.4.6.12019-08-19019 August 2019 Regarding Condition Prohibited by Technical Specification 3.4.6.1 05000395/LER-2019-001, Condition Prohibited by Technical Specification 3.4.6.12019-04-15015 April 2019 Condition Prohibited by Technical Specification 3.4.6.1 RC-18-0049, LER 2018-001-01 Tor Virgil C. Summer, Unit 1, Valid Actuation of Emergency Diesel Generator2018-05-0707 May 2018 LER 2018-001-01 Tor Virgil C. Summer, Unit 1, Valid Actuation of Emergency Diesel Generator 05000395/LER-2018-001-01, Tor Virgil C. Summer, Unit 1, Valid Actuation of Emergency Diesel Generator2018-05-0707 May 2018 Tor Virgil C. Summer, Unit 1, Valid Actuation of Emergency Diesel Generator 05000395/LER-2016-001-02, (Vcsns), Unit 1 - Licensee Event Reports (2016-001-02, 2016-002-01, 2016-003-02) - Revision to Correct Typographical Errors2018-04-25025 April 2018 (Vcsns), Unit 1 - Licensee Event Reports (2016-001-02, 2016-002-01, 2016-003-02) - Revision to Correct Typographical Errors 05000395/LER-2018-001, Valid Actuation of Emergency Diesel Generator2018-03-19019 March 2018 Valid Actuation of Emergency Diesel Generator 05000395/LER-1917-005, V.C Summer, Unit 1, Regarding Automatic Reactor Trip Due to Main Turbine Trip2017-12-22022 December 2017 V.C Summer, Unit 1, Regarding Automatic Reactor Trip Due to Main Turbine Trip 05000395/LER-1917-006, Regarding Technical Specification Action Not Met for Inoperable Oxygen Monitor2017-12-15015 December 2017 Regarding Technical Specification Action Not Met for Inoperable Oxygen Monitor 05000395/LER-1917-003, For Virgil C. Summer Nuclear Station, Unit 1, Regarding Failed Lightning Arrester on Main Transformer Causes Reactor Trip2017-10-26026 October 2017 For Virgil C. Summer Nuclear Station, Unit 1, Regarding Failed Lightning Arrester on Main Transformer Causes Reactor Trip 05000395/LER-1917-002, Regarding Low Feedwater Flow to the B Steam Generator Causes Automatic Reactor Trip2017-08-25025 August 2017 Regarding Low Feedwater Flow to the B Steam Generator Causes Automatic Reactor Trip 05000395/LER-1917-001, Regarding C Main Feedwater Failure to Trip Results in Loss of Emergency Feedwater Auto Start Actuation Signal2017-07-24024 July 2017 Regarding C Main Feedwater Failure to Trip Results in Loss of Emergency Feedwater Auto Start Actuation Signal 05000395/LER-2016-003-01, Regarding Steam Propagation Door Discovered Propped Open2017-02-0909 February 2017 Regarding Steam Propagation Door Discovered Propped Open 05000395/LER-2016-004-01, Regarding Steam Propagation Barrier Degrade Due to Missing Orifices2017-02-0101 February 2017 Regarding Steam Propagation Barrier Degrade Due to Missing Orifices 05000395/LER-2016-006, Regarding Circuit 1 Hot Gas Bypass Valve Failure Renders A-Train Chiller Non-functional and A-Train Charging Pump Inoperable2016-12-15015 December 2016 Regarding Circuit 1 Hot Gas Bypass Valve Failure Renders A-Train Chiller Non-functional and A-Train Charging Pump Inoperable 05000395/LER-2016-005, Regarding Steam Propagation Barrier Degraded Due to Removal of Ventilation Duct Access Panel for Surveillance Activities2016-12-0505 December 2016 Regarding Steam Propagation Barrier Degraded Due to Removal of Ventilation Duct Access Panel for Surveillance Activities 05000395/LER-2016-004, Steam Propagation Barrier Degraded Due to Missing Orifices2016-11-14014 November 2016 Steam Propagation Barrier Degraded Due to Missing Orifices 05000395/LER-2016-003, Regarding Steam Propagation Door Discovered Propped Open2016-11-14014 November 2016 Regarding Steam Propagation Door Discovered Propped Open 05000395/LER-2016-001-01, Transmittal of Low Refrigerant Renders A-Chiller Non-Functional and A-Charging Pump Inoperable2016-10-25025 October 2016 Transmittal of Low Refrigerant Renders A-Chiller Non-Functional and A-Charging Pump Inoperable 05000395/LER-2016-002, Regarding Pressurizer Heater Inoperable Longer than Technical Specification Limiting Condition for Operation 3.4.32016-09-0808 September 2016 Regarding Pressurizer Heater Inoperable Longer than Technical Specification Limiting Condition for Operation 3.4.3 RC-15-0190, Special Report (Spr) 2014-005-01, Loss or Theft of License Material2015-12-16016 December 2015 Special Report (Spr) 2014-005-01, Loss or Theft of License Material RC-15-0179, Special Report (Spr) 2015-002 Regarding One or More Required Meteorological Monitoring Channels Being Inoperable for More than Seven (7) Days2015-11-0303 November 2015 Special Report (Spr) 2015-002 Regarding One or More Required Meteorological Monitoring Channels Being Inoperable for More than Seven (7) Days RC-15-0139, Submittal of Special Report (Spr) 2015-001 Regarding the Loose-Part Monitoring System (Lpms) Channel Number 8 Being Inoperable in Excess of 30 Days2015-08-20020 August 2015 Submittal of Special Report (Spr) 2015-001 Regarding the Loose-Part Monitoring System (Lpms) Channel Number 8 Being Inoperable in Excess of 30 Days 05000395/LER-2015-002, Regarding Low Oil Level Trip Renders Chillers Non-Functional and a Train of Charging System Inoperable2015-06-0808 June 2015 Regarding Low Oil Level Trip Renders Chillers Non-Functional and a Train of Charging System Inoperable 05000395/LER-2015-001, Regarding Reactor Building Spray Isolation Valve Failure Renders Train of Reactor Building Spray Inoperable2015-05-12012 May 2015 Regarding Reactor Building Spray Isolation Valve Failure Renders Train of Reactor Building Spray Inoperable 05000395/LER-2014-004, For V. C. Summer, Unit 1 - Condensate System Bypass Valve Failure and a Procedure Deficiency Cause Loss of Feedwater and Automatic Reactor Trip2014-09-19019 September 2014 For V. C. Summer, Unit 1 - Condensate System Bypass Valve Failure and a Procedure Deficiency Cause Loss of Feedwater and Automatic Reactor Trip 05000395/LER-2014-003, Regarding Component Cooling System Emergency Makeup a Valve Failed to Stroke Open Rendering Train of Component Cooling Inoperable2014-06-24024 June 2014 Regarding Component Cooling System Emergency Makeup a Valve Failed to Stroke Open Rendering Train of Component Cooling Inoperable 05000395/LER-2014-002, Regarding Reactor Vessel Head Penetration Weld Indications Attributed to Primary Water Stress Corrosion Cracking2014-06-16016 June 2014 Regarding Reactor Vessel Head Penetration Weld Indications Attributed to Primary Water Stress Corrosion Cracking 05000395/LER-2014-001, V. C. Summer Nuclear Station Unit 1, Regarding Component Cooling System Emergency Makeup B Valve Failed to Stroke Open Rendering Train of Component Cooling Inoperable2014-06-12012 June 2014 V. C. Summer Nuclear Station Unit 1, Regarding Component Cooling System Emergency Makeup B Valve Failed to Stroke Open Rendering Train of Component Cooling Inoperable RC-14-0084, Special Report 2014-003 for V.C. Summer, One or More Required Meteorological Monitoring Channels Being Inoperable for More than Seven (7) Days2014-05-14014 May 2014 Special Report 2014-003 for V.C. Summer, One or More Required Meteorological Monitoring Channels Being Inoperable for More than Seven (7) Days RC-14-0085, Special Report 2014-002 for V.C. Summer, Degraded Conditions Lasting Longer than Seven Days2014-05-14014 May 2014 Special Report 2014-002 for V.C. Summer, Degraded Conditions Lasting Longer than Seven Days 05000395/LER-2013-006, Regarding Securing Control Room Ventilation Emergency Recirculation While Associated Radiation Monitor Was Out of Service2014-01-31031 January 2014 Regarding Securing Control Room Ventilation Emergency Recirculation While Associated Radiation Monitor Was Out of Service 05000395/LER-2013-005, Regarding Unfused Direct Current Ammeter Circuits in Control Room Result in 10 CFR 50 Appendix R Unanalyzed Condition2013-12-11011 December 2013 Regarding Unfused Direct Current Ammeter Circuits in Control Room Result in 10 CFR 50 Appendix R Unanalyzed Condition 05000395/LER-2013-004, Regarding Spray System Relief Valve Failure to Lift at Required Setpoint Renders the Reactor Building Spray System Inoperable2013-09-30030 September 2013 Regarding Spray System Relief Valve Failure to Lift at Required Setpoint Renders the Reactor Building Spray System Inoperable 05000395/LER-2013-003, Trip Setpoint Renders Chiller and Control Room Emergency Filtration Inoperable2013-08-21021 August 2013 Trip Setpoint Renders Chiller and Control Room Emergency Filtration Inoperable 05000395/LER-2013-002, V. C. Summer Nuclear Station, Unit 1, Regarding Component Cooling System Emergency Makeup Valve Failed to Stroke Open2013-06-19019 June 2013 V. C. Summer Nuclear Station, Unit 1, Regarding Component Cooling System Emergency Makeup Valve Failed to Stroke Open 05000395/LER-2013-001, V. C. Summer Nuclear Station, Unit 1, Regarding Grid Disturbance Results in an Engineered Safeguard Features Actuation of the a EDG2013-05-22022 May 2013 V. C. Summer Nuclear Station, Unit 1, Regarding Grid Disturbance Results in an Engineered Safeguard Features Actuation of the a EDG 05000395/LER-2012-003, Regarding Reactor Vessel Head Penetrations Not Meeting Requirements of 10 CFR50.55(g)(6)(ii)(D)2012-12-0606 December 2012 Regarding Reactor Vessel Head Penetrations Not Meeting Requirements of 10 CFR50.55(g)(6)(ii)(D) 2024-04-17
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text
V.C. Summer Nuclear Station Bradham Blvd & Hwy 215, Jenkinsville, SC 29065 Mailing Address:
P.O. Box 88, Jenkinsville, SC 29065 DominionEnergy.com Document Control Desk August 26, 2021 U.S. Nuclear Regulatory Commission Washington, DC 20555 DOMINION ENERGY SOUTH CAROLINA (DESC)
~ Dominion
~
Energy Serial No.: 21-258 VCS-LIC/JB RO Docket No. 50-395 License No. NPF-12 VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) UNIT 1 LICENSEE EVENT REPORT 2021-001-00 CONDITION PROHIBITED BY TECHNICAL SPECIFICATIONS Dominion Energy South Carolina hereby submits Licensee Event Report (LER) 2021 -001 -00 for VCSNS. This report provides details concerning an operation or condition prohibited by Technical Specifications and is submitted in accordance with 10 CFR 50.73(a)(2)(i)(B). The attached LER also fulfills "Reporting of Defects and Noncompliance" requirements under 10 CFR 21.2(c).
Should you have any questions, please call Mr. Justin Bouknight at (803) 941-9828.
Sincerely, George A. Lippard Site Vice President V.C. Summer Nuclear Station Enclosure Commitments contained in this letter: None cc:
G. J. Lindamood - Santee Cooper L. Dudes - NRG Region II V. Thomas - NRG Project Mgr.
NRG Resident Inspector J. N. Bassett - INPO Marsh USA, Inc.
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMS: NO. 3150-0104 EXPIRES: 08/31/2023 (08-2020)
- 3. Page V.C. Summer Nuclear Station, Unit 1 05000 395 1 OF 4
- 4. Title Condition Prohibited 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 Docket Number Number No.
05000 06 28 2021 2021 - 001 -
00 8
26 2021 Facility Name Docket Number 05000
- 9. Operating Mode 110. Power Level 1
100%
)
In 2010, Nuclear Logistics (NLI) was contracted by V.C. Summer Nuclear Station (VCSNS) to replace its 3 safety-related chillers. On June 28, 2021, V.C. Summer Nuclear Station (VCSNS) was notified that the bolted diagonal supports for the NU safety related chillers (XHX0001 A/1 B/1 C) have a bolt (the pin) which would not withstand the combined design seismic and thermal loads. The vendor conclusion was confirmed by VCSNS personnel. As a result, the previous NU chiller support frame design does not meet required seismic qualification under VCSNS procurement specification for compliance with 10 CFR 50 Appendix A, Criterion 2. At the time of discovery, only the 'A' Chiller had been replaced. Additional support bracing was designed, fabricated, and installed for the affected in-service 'A' Chiller. The enhanced bracing installation has corrected the issue and restored compliance with Technical Specifications (TS). There were no seismic events of consequence to the 'A' Chiller functionality during the time of the deficient seismic restraint (February 17, 2017 until June 29, 2021). However, there were times when the 'A' Chiller was credited as a TS support component, resulting in the plant operating in a condition prohibited by TS.
1.0 DESCRIPTION OF THE EVENT In 2010, NU (now a part of Paragon Energy Solutions) was contracted by V.C. Summer Nuclear Station (VCSNS) to provide 3 replacement safety-related chillers. On June 28, 2021, Paragon Energy Solutions notified V.C. Summer Nuclear Station (VCSNS) that the bolted diagonal supports for the NU safety-related chillers (XHX0001A/1 B/1 C) have a bolt (the pin) which cannot withstand the combined seismic and thermal loads. The deficiency was confirmed by VCSNS personnel, following review of the vendor documentation. As a result, the NLI chiller support frame design did not meet required seismic qualification under VCSNS procurement specification for compliance with 10 CFR 50 Appendix A, Criterion 2. At the time of discovery, only the 'A' Chiller had been replaced. The 'B' Chiller was in the process of being replaced. The 'C' Chiller was operable, with its replacement being fabricated by the vendor. This condition had existed for the 'A' Chiller since February 17, 2017. The 'A' Train of Chilled Water was declared non-functional at 1435 hrs on June 28, 2021 and the station entered Technical Specification (TS) Action Statement 3.5.2.a.
Additional support bracing was designed, fabricated, and installed for the affected in-service 'A' Chiller. The action statement was exited within the allowable 72-hour outage time on June 29, 2021 at 1030 hrs. The enhanced design was applied to the 'B' Chiller, prior to its return to service, and will be applied to the replacement 'C' Chiller at the vendor facility prior to its delivery and installation. The enhanced bracing installation has corrected the issue and brought the issue in line with VCSNS seismic design specifications. There were no seismic events of consequence to the 'A' Chiller functionality during the time of the deficient seismic restraint.
2.0 SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS
Although not specifically addressed in TS, Safety Related Chilled Water is required for operability of TS-required equipment. The 'A' Chiller was installed February 17, 2017 and subsequently credited as a TS support component. A past functionality evaluation performed on the 'A' Chiller determined the 'A' Chiller was non-functional, as a result of inadequate seismic restraints, from February 17, 2017 to June 29, 2021. During this period, there were occasions when
'A' Chiller was one of two chillers credited for support of the Emergency Core Cooling System (ECCS) equipment, required per TS 3.5.2. The most-limiting ECCS component supported by the Safety Related Chilled Water are the charging pumps. The non-functional 'A' Chiller could have also impacted availability of the Control Room Emergency Filtration System (CREFS) (TS 3.7.6) and potentially other safety-related equipment for some scenarios. These past condition(s) prohibited by TS were not known until Paragon submitted the Part 21 information on June 28, 2021. There were no seismic events of consequence to the 'A' Chiller functionality during the time of the deficient seismic restraint (February 17, 2017 until June 29, 2021).
The Chilled Water System provides cooling to safety-related areas (TS Table 3.7-7) as an attendant cooling system and supports the comfort requirements for the Control Room Emergency Filtration Systems (CREFS). The Chilled Water System is necessary to ensure equipment located within these areas can withstand the environmental effects of a postulated FSAR chapter 15 event.
The 'A' Chiller (XHX0001A) is designed to provide a continuous flow of 45 deg F chilled water to various safety-related cooling coils in the plant during both normal and emergency conditions. All TS areas in Table 3.7-7, with the exception of Areas 23-30 (cooled by outside air ventilation), are cooled by chilled water air handling units. If the temperature limits for any room listed in TS Table 3.7-7 are exceeded for more than eight hours, a Special Report demonstrating operability of the pertinent equipment is required per TS 3.7.9.a. If those values are exceeded by more than 30 deg F for more than 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> the equipment in the room is considered inoperable per TS 3.7.9.b.
In order for the 'A' Chiller to continuously deliver 45 deg F water, all heat loads generated in the areas served by the Chilled Water System must be transferred to the chilled water fluid, and absorbed by the refrigeration system, which is then rejected to the Service Water System. The 'A' Chiller is designed to provide this function under all operating scenarios.
Therefore, it is required to operate continuously, when started on demand, and the total heat removal rate (cooling capacity) must meet or exceed the total steady-state heat load rates for the Chilled Water System supported areas. This is required during both normal and accident heat load conditions, provided the system is Seismic Category I components.
3.0 CAUSE OF THE EVENT
The cause of the non-functionality was the inadequate seismic design for bracing on the installed 'A' Chiller, as well as for the 'B' was in the process of being installed. Specifically, the issue was the bolts (pins) utilized in the seismic bracing design were not adequate for the design load.
4.0 CORRECTIVE ACTIONS
Additional support bracing was designed, fabricated, and installed for the affected in-service 'A' Chiller. This modification was completed on the installed 'A' Chiller on June 29, 2021. The same design modification was applied to the 'B' Chiller prior to its return to service and will be applied to the enhanced 'C' Chiller prior to its installation. The enhanced seismic restraint has corrected the issue, restoring compliance with the VCSNS seismic design and TS.
VCSNS personnel have engaged with Paragon regarding the design and fabrication of its chillers and continue to provide oversight in accordance with procurement and quality assurance program requirements.
5.0 SIMILAR EVENTS
A review of Licensee Event Reports (LERs) and condition reports (CRs) at VCSNS for the three previous years did not identify any similar events.
6.0 MANUFACTURER I MODEL INFORMATION Paragon/Nuclear Logistics (NU) 280-ton Custom Chillers, Serial Numbers XHX-0001A, XHX-0001 B, and XHX-0001 C.
The Chillers were originally supplied to VC Summer Nuclear Station by Nuclear Logistics under purchase order NU-02SR726683 in 2010.
7.0 ADDITIONAL INFORMATION
While this LER describes a condition that could have had adverse impacts to equipment qualification following a seismic event, there was no such event. As a result, the chilled water system and the equipment it supports were not impacted by the design vulnerability that has now been corrected. Page 4
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