ML25052A020
| ML25052A020 | |
| Person / Time | |
|---|---|
| Site: | 05000025, 05000026 |
| Issue date: | 02/28/2025 |
| From: | John Lamb NRC/NRR/DORL/LPL2-1 |
| To: | Coleman J Southern Nuclear Operating Co |
| Lamb J, NRR/DORL/LPL2-1 | |
| References | |
| EPID L-2024-LLA-0101 | |
| Download: ML25052A020 (1) | |
Text
February 28, 2025 Jamie M. Coleman Director, Regulatory Affairs Southern Nuclear Operating Company, Inc.
3535 Colonnade Parkway, Bin N-274-EC Birmingham, AL 35243
SUBJECT:
VOGTLE ELECTRIC GENERATING PLANT, UNITS 3 AND 4 ISSUANCE OF AMENDMENTS TO REVISE TECHNICAL SPECIFICATION 3.7.6, MAIN CONTROL ROOM EMERGENCY HABITABILITY SYSTEM (VES), ACTION A AND SURVEILLANCE REQUIREMENT 3.7.6.6 (EPID NO. L-2024-LLA-0101)
Dear Jamie Coleman:
In response to your application dated July 25, 2024, the U.S. Nuclear Regulatory Commission (NRC) has issued the enclosed Amendment Nos. 199 and 195 to Combined License (COL)
Nos. NPF-91 and NPF-92 for Vogtle Electric Generating Plant (Vogtle), Units 3 and 4, respectively. The amendment revises Technical Specifications (TS) 3.7.6, Main Control Room Emergency Habitability System (VES), Action A, and Surveillance Requirement (SR) 3.7.6.6 related to inoperable valves and/or dampers.
A copy of the related safety evaluation, which includes the NRC staffs evaluation of the amendment, is enclosed. The notice of issuance of the amendment documents included in this letter will be published in the Federal Register.
In accordance with Title 10 of the Code of Federal Regulations (10 CFR) Part 2, Agency Rules of Practice and Procedure, a copy of this letter will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records component of the NRCs Agencywide Documents Access and Management System (ADAMS).
ADAMS is accessible from the NRC website at http://www.nrc.gov/reading-rm/adams.html.
If you have questions, please contact me at 301-415-3100 or John.Lamb@nrc.gov.
Sincerely,
/RA/
John G. Lamb, Senior Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos.: 52-025 and 52-026
Enclosures:
- 1. Amendment No. 199 to Vogtle, Unit 3, COL
- 2. Amendment No. 195 to Vogtle, Unit 4, COL
- 3. Safety Evaluation cc: Listserv SOUTHERN NUCLEAR OPERATING COMPANY, INC.
GEORGIA POWER COMPANY OGLETHORPE POWER CORPORATION MEAG POWER SPVM, LLC MEAG POWER SPVJ, LLC MEAG POWER SPVP, LLC CITY OF DALTON, GEORGIA VOGTLE ELECTRIC GENERATING PLANT, UNIT 3 DOCKET NO.52-025 AMENDMENT TO FACILITY COMBINED LICENSE Amendment No. 199 License No. NPF-91
- 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment by Southern Nuclear Operating Company (SNC),
dated July 25, 2024, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act) and the Commissions regulations set forth in 10 CFR Chapter I; B.
The facility will be constructed and will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.
There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D.
The issuance of this amendment will not be inimical to the common defense and security or the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations, and all applicable requirements have been satisfied.
- 2.
Accordingly, the license is amended by changes to Appendix A, Technical Specifications, of the facility Combined License as indicated in the attachment to this license amendment. Paragraph 2.D(8) of facility Combined License No. NPF-91 is hereby amended to read as follows:
(8) Incorporation The Technical Specifications and Environmental Protection Plan in Appendices A and B, respectively, of this license, as revised through Amendment No. 199, are hereby incorporated into this license.
- 3.
This license amendment is effective as of the date of its issuance and shall be implemented within 90 days of the date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION:
Michael Markley, Chief Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Date of Issuance: February 28, 2025
Attachment:
- 1. Page 7 of the facility Combined License and affected pages of Appendix A of the facility Combined License MICHAEL MARKLEY Digitally signed by MICHAEL MARKLEY Date: 2025.02.28 17:52:11 -05'00'
SOUTHERN NUCLEAR OPERATING COMPANY, INC.
GEORGIA POWER COMPANY OGLETHORPE POWER CORPORATION MEAG POWER SPVM, LLC MEAG POWER SPVJ, LLC MEAG POWER SPVP, LLC CITY OF DALTON, GEORGIA VOGTLE ELECTRIC GENERATING PLANT, UNIT 4 DOCKET NO.52-026 AMENDMENT TO FACILITY COMBINED LICENSE Amendment No. 195 License No. NPF-92
- 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment by Southern Nuclear Operating Company (SNC),
dated July 25, 2024, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act) and the Commissions regulations set forth in 10 CFR Chapter I; B.
The facility will be constructed and will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.
There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D.
The issuance of this amendment will not be inimical to the common defense and security or the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations, and all applicable requirements have been satisfied.
- 2.
Accordingly, the license is amended by changes to Appendix A, Technical Specifications, of the facility Combined License as indicated in the attachment to this license amendment. Paragraph 2.D(8) of facility Combined License No. NPF-92 is hereby amended to read as follows:
(8) Incorporation The Technical Specifications and Environmental Protection Plan in Appendices A and B, respectively, of this license, as revised through Amendment No. 195, are hereby incorporated into this license.
- 3.
This license amendment is effective as of the date of its issuance and shall be implemented within 90 days of the date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION:
Michael Markley, Chief Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Date of Issuance: February 28, 2025
Attachment:
Page 7 of the facility Combined License and affected pages of Appendix C of the facility Combined License MICHAEL MARKLEY Digitally signed by MICHAEL MARKLEY Date: 2025.02.28 17:53:08 -05'00'
ATTACHMENT TO LICENSE AMENDMENT NOS. 199 AND 195 TO FACILITY COMBINED LICENSE NOS. NPF-91 AND NPF-92 DOCKET NOS.52-025 AND 52-026 Replace the following pages of the facility Combined License Nos. NPF-91 and NPF-92 with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.
Facility Combined License No. NPF-91 REMOVE INSERT 7
7 Facility Combined License No. NPF-92 REMOVE INSERT 7
7 Appendix A to facility Combined License Nos. NPF-91 and NPF-92 REMOVE INSERT 3.7.6-1 3.7.6-1 3.7.6-2 3.7.6-2 3.7.6-4 3.7.6-4
(7)
Reporting Requirements (a)
Within 30 days of a change to the initial test program described in UFSAR Section 14, Initial Test Program, made in accordance with 10 CFR 50.59 or in accordance with 10 CFR Part 52, Appendix D, Section VIII, Processes for Changes and Departures, SNC shall report the change to the Director of NRO, or the Directors designee, in accordance with 10 CFR 50.59(d).
(b)
SNC shall report any violation of a requirement in Section 2.D.(3),
Section 2.D.(4), Section 2.D.(5), and Section 2.D.(6) of this license within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Initial notification shall be made to the NRC Operations Center in accordance with 10 CFR 50.72, with written follow up in accordance with 10 CFR 50.73.
(8)
Incorporation The Technical Specifications and Environmental Protection Plan in Appendices A and B, respectively, of this license, as revised through Amendment No. 199, are hereby incorporated into this license.
(9)
Technical Specifications The technical specifications in Appendix A to this license become effective upon a Commission finding that the acceptance criteria in this license (ITAAC) are met in accordance with 10 CFR 52.103(g).
(10)
Operational Program Implementation SNC shall implement the programs or portions of programs identified below, on or before the date SNC achieves the following milestones:
(a)
Environmental Qualification Program implemented before initial fuel load; (b)
Reactor Vessel Material Surveillance Program implemented before initial criticality; (c)
Preservice Testing Program implemented before initial fuel load; (d)
Containment Leakage Rate Testing Program implemented before initial fuel load; (e)
- 1.
The fire protection measures in accordance with Regulatory Guide (RG) 1.189 for designated storage building areas (including adjacent fire areas that could affect the storage area) implemented before initial receipt 7
Amendment No. 199
7 Amendment No. 195 (7)
Reporting Requirements (a)
Within 30 days of a change to the initial test program described in UFSAR Section 14, Initial Test Program, made in accordance with 10 CFR 50.59 or in accordance with 10 CFR Part 52, Appendix D, Section VIII, Processes for Changes and Departures, SNC shall report the change to the Director of NRO, or the Directors designee, in accordance with 10 CFR 50.59(d).
(b)
SNC shall report any violation of a requirement in Section 2.D.(3),
Section 2.D.(4), Section 2.D.(5), and Section 2.D.(6) of this license within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Initial notification shall be made to the NRC Operations Center in accordance with 10 CFR 50.72, with written follow up in accordance with 10 CFR 50.73.
(8)
Incorporation The Technical Specifications and Environmental Protection Plan in Appendices A and B, respectively, of this license, as revised through Amendment No. 195, are hereby incorporated into this license.
(9)
Technical Specifications The technical specifications in Appendix A to this license become effective upon a Commission finding that the acceptance criteria in this license (ITAAC) are met in accordance with 10 CFR 52.103(g) with the following exceptions:
(a)
Prior to initial criticality of the reactor core while operating in plant operational Mode 5 (Cold Shutdown) or Mode 6 (Refueling) the following TS are temporarily excluded from becoming effective:
TS 3.3.8, Engineered Safety Feature Actuation System (ESFAS)
Instrumentation, Table 3.3.8-1 o Function 14, RCS Wide Range Pressure - Low o Function 15, Core Makeup Tank (CMT) Level - Low 3 o Function 16, CMT Level - Low 6 o Function 18, IRWST Lower Narrow Range Level - Low 3 TS 3.3.9, Engineered Safety Feature Actuation System (ESFAS)
Manual Initiation, Table 3.3.9-1 o Function 1, Safeguards Actuation - Manual Initiation o Function 6, ADS Stages 1, 2 & 3 Actuation - Manual Initiation o Function 7, ADS Stage 4 Actuation - Manual Initiation o Function 8, Passive Containment Cooling Actuation - Manual Initiation o Function 9, Passive Residual Heat Removal Heat Exchanger Actuation - Manual Initiation
Technical Specifications
- 3. 7 PLANT SYSTEMS 3.7.6 Main Control Room Emergency Habitability System (VES)
LCO 3.7.6 APPLICABILITY:
ACTIONS The VES shall be OPERABLE.
- NOTE -
The main control room envelope (MCRE) boundary may be opened intermittently under administrative control.
MODES 1, 2, 3, and 4, During movement of irradiated fuel assemblies.
VES 3.7.6 CONDITION REQUIRED ACTION COMPLETION TIME A.
- NOTE -
Separate Condition entry is allowed for each valve and each damper.
One or more valves inoperable with VES safety function maintained.
OR One or more dampers inoperable with VES safety function maintained.
B.
One PMS Division inoperable in one or more MCR load shed panel(s).
VEGP Units 3 and 4 A.1 B.1 Restore valve or damper to 7 days OPERABLE status.
Restore PMS division in both MCR load shed panels to OPERABLE status.
3.7.6 - 1 7 days Amendment No. 199 (Unit 3)
Amendment No. 195 (Unit 4)
ACTIONS (continued)
CONDITION C.
Thermal mass of one or more required heat sink(s) not within limit(s).
D.
VES inoperable due to inoperable MCRE boundary in MODE 1, 2, 3, or 4.
E.
One bank of VES air tanks inoperable.
VEGP Units 3 and 4 Technical Specifications VES 3.7.6 C.1 AND C.2 0.1 AND 0.2 AND 0.3 E.1 AND E.2 AND E.3 REQUIRED ACTION COMPLETION TIME Restore required heat sink 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> air temperatures to within limit(s).
Restore thermal mass of 5 days required heat sink(s) to within limit(s).
Initiate action to implement Immediately mitigating actions.
Verify mitigating actions 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> ensure MCRE occupant exposures to radiological, chemical, and smoke hazards will not exceed limits.
Restore MCRE boundary 90 days to OPERABLE status.
Verify that the OPERABLE 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> tanks contain
> 245,680 scf of AND compressed air.
Once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter Verify VBS MCRE ancillary 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> fans and supporting equipment are available.
Restore VES to 7 days OPERABLE status.
3.7.6 - 2 Amendment No. 199 (Unit 3)
Amendment No. 195 (Unit 4)
Technical Specifications SURVEILLANCE REQUIREMENTS SURVEILLANCE SR 3.7.6.1 Verify the compressed air storage tanks contain
> 327,574 scf of compressed air.
SR 3.7.6.2 Verify thermal mass for the following heat sink locations is within limit:
- a.
MCRE;
- b.
Each required individual room adjacent to and below MCRE; C.
Each required room-pair adjacent to and below MCRE; and
- d.
Room above MCRE.
SR 3.7.6.3 Operate VES for ~ 15 minutes.
SR 3.7.6.4 Verify each VES air header manual isolation valve is in an open position.
SR 3.7.6.5 Verify the air quality of the air storage tanks meets the requirements of Appendix C, Table C-1 of ASHRAE Standard 62 with a pressure dew point of::; 40°F at
~ 3400 psig.
SR 3.7.6.6 Verify each MCRE isolation valve is OPERABLE and will close upon receipt of an actual or simulated actuation signal, except for valves that are locked, sealed, or otherwise secured in the closed position.
SR 3.7.6.7 Verify each VES pressure relief isolation valve within the MCRE pressure boundary is OPERABLE.
SR 3.7.6.8 Verify each VES pressure relief damper is OPERABLE.
VES 3.7.6 FREQUENCY 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 24 hours 31 days on a STAGGERED TEST BASIS 31 days 92 days 24 months In accordance with the lnservice Testing Program 24 months VEGP Units 3 and 4 3.7.6 - 4 Amendment No. 199 (Unit 3)
Amendment No. 195 (Unit 4)
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 199 AND 195 TO THE COMBINED LICENSE NOS. NPF-91 AND NPF-92 SOUTHERN NUCLEAR OPERATING COMPANY, INC.
GEORGIA POWER COMPANY OGLETHORPE POWER CORPORATION MEAG POWER SPVM, LLC MEAG POWER SPVJ, LLC MEAG POWER SPVP, LLC CITY OF DALTON, GEORGIA VOGTLE ELECTRIC GENERATING PLANT, UNITS 3 AND 4 DOCKET NOS.52-025 AND 52-026
1.0 INTRODUCTION
By letter dated July 25, 2024 (Agencywide Documents Access and Management System Accession No. ML24207A252), Southern Nuclear Operating Company (SNC, the licensee) requested that the U.S. Nuclear Regulatory Commission (NRC) amend Vogtle Electric Generating Plant (Vogtle), Units 3 and 4 Combined License (COL) Nos. NPF-91 and NPF-92, respectively. The license amendment request (LAR) proposed to revise Technical Specifications (TS) 3.7.6, Main Control Room Emergency [MCR] Habitability System (VES).
The proposed amendments would revise TS 3.7.6, Action A, and Surveillance Requirement (SR) 3.7.6.6 related to inoperable valves and/or dampers.
2.0 REGULATORY EVALUATION
2.1 Background
The main control room emergency habitability system (VES) supplies breathable quality air for the MCR operators while the MCR is isolated. It provides a protected environment from which operators can control the plant following an uncontrolled release of radioactivity, hazardous chemicals, or smoke.
Technical Specification Limiting Condition for Operation (LCO) 3.7.6 requires that the VES shall be OPERABLE (i.e., capable of performing its specified safety function(s) with all necessary attendant instrumentation, controls, normal or emergency electrical power, cooling and seal water, lubrication, and other auxiliary equipment that are required for the system, subsystem, train, component, or device to perform its specified safety function(s) are also capable of performing their related support function(s)) during reactor MODES 1 (Power Operation),
2 (Startup), 3 (Hot Standby), and 4 (Safe Shutdown), and during movement of irradiated fuel assemblies. Under the existing TS, when LCO 3.7.6 is not met due to one valve or damper being inoperable, then per action 3.7.6.A.1 the licensee has seven days to restore the valve or damper to operable; the licensee may continue full power operation and continue to move irradiated fuel during those seven days. Seven days is based on engineering judgment, considering the low probability of an accident that would result in a significant radiation release from the fuel, the low probability of not containing the radiation, and that the remaining components can provide the required capability. The existing TS address what happens after seven days (or when VES is inoperable for a reason other than the those addressed in TS, which would include more than one valve or damper being inoperable), with TS 3.7.6.F.1 and F.2 requiring leaving power operation then going to MODE 3 then MODE 5 (Cold Shutdown),
and with TS 3.7.6.G.1 requiring an immediate cessation of movement of irradiated fuel assemblies. The VES is not required to be OPERABLE in MODES 5 (Cold Shutdown) and 6 (Refueling) when irradiated fuel is not being moved because accidents resulting in fission product release are not postulated.
The VES is designed to operate following a design basis accident (DBA), which requires protection from the release of radioactivity. In these events, the nuclear island non-radioactive ventilation system (VBS) would continue to function if alternating current (AC) power is available. If AC power is lost for greater than 10 minutes, or if MCR differential pressure is below the Low setpoint for more than 10 minutes, or a Control Room Air Supply Radiation (particulate or iodine) High 2 (Limiting Condition for Operation (LCO) 3.3.13) signal is received, the VES is actuated.
The major functions of the VES are: (1) to provide forced ventilation to deliver an adequate supply of breathable air for the MCR occupants; (2) to provide forced ventilation to maintain the main control room envelope (MCRE) at a 1/8-inch water gauge positive pressure with respect to the surrounding areas; (3) to provide passive filtration to filter contaminated air in the MCR; and (4) to limit the temperature increase of the MCR equipment and facilities that must remain functional during an accident, via the heat absorption of passive heat sinks.
The VES consists of 32 compressed air storage tanks arranged in four banks of eight tanks each, two air delivery flow paths consisting of two main (with two parallel automatically actuated flow paths) and an alternate (a manually actuated flow path) air delivery flow path, an eductor, a high efficiency particulate air (HEPA) filter, an activated charcoal adsorber section for removal of gaseous activity (principally iodines), associated valves or dampers, piping, and instrumentation. The tanks contain enough breathable air to supply the required air flow to the MCRE for at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
The VES system is designed to maintain carbon dioxide concentration less than 0.5 percent by volume for up to 11 MCR occupants and to maintain air quality within the guidelines of Table 1 and Appendix C, Table C-1, of American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 62 - 1989, Ventilation for Acceptable Indoor Air Quality.
The MCRE contains the spaces that operators inhabit to control the unit during normal and accident conditions. This area encompasses the main control area, operations work area, operations break room, shift supervisors office, kitchen, and toilet facilities. The MCRE is protected during normal operation, natural events, and accident conditions. The MCRE boundary is the combination of walls, floor, roof, electrical and mechanical penetrations, and access doors. OPERABILITY of the MCRE boundary must be maintained to ensure that the inleakage of unfiltered air into the MCRE will not exceed the inleakage assumed in the licensing basis analysis of DBA consequences to MCRE occupants. The MCRE and its boundary are defined in the Main Control Room Envelope Habitability Program.
TS 3.7.6, Action A, is required to restore the component to OPERABLE status when a VES valve, a VES damper, or a main control room boundary isolation valve is inoperable. SR 3.7.6.6 requires verification every 24 months that all MCRE isolation valves are OPERABLE and will close upon receipt of an actual or simulated actuation signal.
2.2 Regulations The NRC staff considered the following regulatory requirements in reviewing the LAR.
In accordance with paragraph C.6. of Section VIII Processes for Changes and Departures of Appendix D to Part 52 Design Certification Rule for the AP1000 Design, changes to the plant-specific TS will be treated as license amendments under Title 10 of the Code of Federal Regulations (10 CFR) Section 50.90. Pursuant to 10 CFR 50.90, whenever a Combined License holder desires to amend the license, application for an amendment must be filed with the Commission fully describing the changes desired, and following as far as applicable, the form prescribed for original applications. Per 10 CFR 52.79(a), an application for a Combined License must contain a final safety analysis report that describes the facility, presents the design bases and the limits on its operation, and presents a safety analysis of the structures, systems, and components of the facility as a whole.
Per 10 CFR 52.79(a)(11), the application for a Combined License shall include proposed TSs prepared in accordance with the requirements of 10 CFR 50.36. The regulation 10 CFR 50.36(c)(2)(i) requires that TS include LCO that are the lowest functional capability or performance levels of equipment required for safe operation of the facility. Further, per 10 CFR 50.36(c)(2)(i), when an LCO is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the TS until the LCO can be met. Per 10 CFR 50.36(c)(3), TS will include SR that are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the LCOs will be met. Per 10 CFR 52.97(c), a Combined License shall contain the terms and conditions, including TSs, as the Commission deems necessary and appropriate.
Under 10 CFR 50.92(a), determinations on whether to grant an applied-for license amendment are to be guided by the considerations that govern the issuance of initial licenses to the extent applicable and appropriate. Both the common standards for licenses in 10 CFR 50.40(a)
(regarding, among other things, consideration of the operating procedures, the facility and equipment, the use of the facility, and other TSs, or the proposals) and those specifically for issuance of combined licenses in 10 CFR 52.97(a)(3), provide that there must be reasonable assurance that the activities at issue will not endanger the health and safety of the public, and that the applicant will comply with the Commissions regulations.
The regulation in 10 CFR Part 50, Appendix A, General Design Criteria (GDC) 19, Control room, states, in part, that:
A control room shall be provided from which actions can be taken to operate the nuclear power unit safely under normal conditions and to maintain it in a safe condition under accident conditions, including loss-of-coolant accidents. Adequate radiation protection shall be provided to permit access and occupancy of the control room under accident conditions without personnel receiving radiation exposures in excess of 5 rem whole body, or its equivalent to any part of the body, for the duration of the accident. Equipment at appropriate locations outside the control room shall be provided (1) with a design capability for prompt hot shutdown of the reactor, including necessary instrumentation and controls to maintain the unit in a safe condition during hot shutdown, and (2) with a potential capability for subsequent cold shutdown of the reactor through the use of suitable procedures.
3.0 TECHNICAL EVALUATION
3.1 Current TSs Current TS 3.7.6, Action A, and SR 3.7.6.6 state:
CONDITION REQUIRED ACTION COMPLETION TIME A. One valve or damper inoperable.
A.1 Restore valve or damper to OPERABLE status.
7 days SURVEILLANCE FREQUENCY SR 3.7.6.6 Verify all MCRE isolation valves are OPERABLE and will close upon receipt of an actual or simulated actuation signal.
24 months 3.2 Proposed TSs Revised TS 3.7.6, Action A, and SR 3.7.6.6 would state:
CONDITION REQUIRED ACTION COMPLETION TIME A
- NOTE -
A.1 Restore valve or damper to OPERABLE status.
7 days Separate Condition entry is allowed for each valve and each damper.
One or more valves inoperable with VES safety function maintained.
OR One or more dampers inoperable with VES safety function maintained.
SURVEILLANCE FREQUENCY SR 3.7.6.6 Verify each MCRE isolation valve is OPERABLE and will close upon receipt of an actual or simulated actuation signal, except for valves that are locked, sealed, or otherwise secured in the closed position.
24 months 3.3 Technical Evaluation of the Proposed Changes 3.3.1 TS 3.7.6 Action A In Section 3.1 of Enclosure to the LAR, the licensee states:
Currently, TS 3.7.6 Action A allows only a single valve or damper to be inoperable. However, the VES design consists of various functions to support the VES safety function to maintain the MCR environment suitable for prolonged occupancy throughout the duration of the postulated accidents that require protection from the release of radioactivity, including maintaining CO2 concentration to less than 0.5 percent for up to 11 main control room occupants.
Each function has designed redundancy for single failure protection such that multiple valves and/or dampers may be concurrently inoperable while still retaining the VES safety function.
3.3.2 NRC Staff Evaluation In its submittal, the licensee discussed how the licensee will make the assessment that the safety function would be maintained. The licensee stated that the proposed changes continue to maintain the initial conditions, operating limits, and safety function assumed during normal operation and in the analysis of accidents and anticipated operational occurrences. The licensee also stated that the proposed changes do not adversely impact the function of any related systems. Last, the licensee stated that the proposed changes continue to provide the required functional capability of the safety systems assumed for previously evaluated accidents and anticipated operational occurrences while operating within the TS allowed Completion Time.
The NRC independently evaluated the licensees technical and regulatory justification and for the reasons provided below finds that there is reasonable assurance that the revised actions to be taken when LCO 3.7.6 is not met (i.e., when the VES is not OPERABLE) will provide reasonable assurance of public health and safety. As a threshold matter, usage of the revised TS action 3.7.6.A requires the licensee first to determine that the VES safety function [is]
maintained, so the licensee may not use the seven-day restoration time in the revised TS action 3.7.6.A when the VES safety function is not maintained. Accordingly, the NRC staffs review of the restoration time is premised on the VES safety function being maintained during the entire 7-day period. In Section 3.2 in its submittal, the licensee describes how the changes will be controlled by the plant procedures. The NRC evaluated plant TSs and confirmed that Vogtle, Units 3 and 4, TS 5.4.1 requires the licensee to establish, implement and maintain written procedures covering the activities in RG 1.33, Rev. 2, Quality Assurance Program Requirements, including the control room.
The NRC finds that the 7-day Completion Time for the revised Condition A is unchanged and continues to be reasonable for TS 3.7.6 and, as described in the TS Bases, is based on engineering judgment, considering the low probability of an accident that would result in a significant radiation release from the fuel, the low probability of not containing the radiation, and that the licensee must determine that the VES safety function is maintained before the licensee can use the 7-day restoration time. The licensee stated that procedures changes will be governed by 10 CFR 50.59 process, maintenance rule, and corrective action program. The NRC staff notes that these conforming procedure changes are subject to NRC review in the reactor oversight process.
Detailed NRC staff review of the licensees submittal and justification is provided in the sections below.
Nuclear Island Non-Radioactive Ventilation System (VBS) and Sanitary Drainage System Isolation In Section 3.1 of Enclosure to the LAR, the licensee states, in part, that:
The VBS supply flow path isolation valves (VBS-V186 and -V187) and return flow path isolation valves (VBS-V188 and -V189), toilet exhaust flow path isolation valves (VBS-V190 and -V191), as well as the sanitary vent line flow path isolation valves (SDS-V001 and -V002) provides for redundant isolation capability in each flow path to isolate penetrations in the MCR boundary.
The NRC staff confirmed independently in its review of updated final safety analysis report (UFSAR) (ML23165A215) Figure 9.4.1-1 that each of the VBS supply flowpath and the return flow path is provided with redundant isolation valves and that the isolation safety function is maintained. In UFSAR Section 9.2.6.3, the sanitary drainage system serves a safety-related function of MCRE isolation by providing redundant safety-related isolation valves in the vent line penetrating the MCR and that isolation capability would be maintained even if the VES is inoperable due to one or more valves or dampers being inoperable.
VES Air Delivery In Section 3.1 of Enclosure to the LAR, the licensee states:
The air delivery flow paths consist of a main air delivery flow path with a self-contained two-stage pressure regulating air delivery valve (VES-V002A) and two 100% parallel automatically actuated flow paths (VES-V005A/B).
Additionally, there is a separate 100% alternate air delivery flow path via a manually actuated valve (VES-V001) with a two-stage pressure regulating air delivery valve (VES-V002B). A failure of either stage of the pressure-regulating valve will not cause the valve to fail completely open. A failure of the second stage of the pressure-regulating valve will increase flow from the emergency air storage tanks; however, there is adequate margin in the emergency air storage tanks such that an operator has time to isolate the line and manually actuate the alternative delivery line.
The NRC staff confirmed independently in its review of UFSAR Figure 6.4.2 that VES air delivery consists of (a) the main air delivery flow path with two parallel automatically actuated flow paths, and (b) the alternate air delivery flow path with a manually actuated flow path. Each of main and alternate air delivery flow path consists of a pressure regulating valve. The licensee states that the failure of either stage of the pressure regulating valve will not cause the valve to fail completely open and the failure of the second stage will increase the flow from the air delivery tanks, which can be accommodated by the operator isolating the line and manually actuating the alternate delivery line. Based on the above, the NRC staff finds there is reasonable assurance that that the VES safety function can be maintained even if the VES is inoperable due to one or more valves or dampers being inoperable VES Distribution Flow In Section 3.1 of Enclosure to the LAR, the licensee states, in part, that:
The VES MCR air filtration line balancing dampers (VES-D002 and -D003) provide flow distribution in the ducting for delivery of recirculated air throughout the MCR boundary. The dampers split flow between the Main Control Area and the Shift Managers Office. The air delivery ducting and dampers comprise the distribution function. Single failure analysis demonstrates acceptable VES performance in the event one of these dampers fails.
The NRC staff confirmed independently in its review of UFSAR Figure 6.4.2 that each flow path is provided with redundant flow assuming the function is maintained. Based on the above, the NRC staff has reasonable assurance the licensees failure analysis shows sufficient VES performance for failure of a damper. The NRC staff concludes that VES safety function can be maintained even if the VES is inoperable due to one or more valves or dampers being inoperable VES Pressure Relief In Section 3.1 of Enclosure to the LAR, the licensee states that:
The VES pressure relief isolation valves and pressure relief dampers open to ensure that adequate vent area is available to mitigate MCRE overpressurization.
The two redundant pressure relief flow paths (VES-V022A with VES-D001A and VES-V022B with VES-D001B) comprise the pressure relief function. The design provides single failure protection to maintain the pressure relief safety function.
Additionally, each pressure relief flow path is also required to be closed when not relieving pressure to maintain the MCRE boundary. Each flow path is provided with redundant isolation devices to ensure that at least one is available assuming a single failure to maintain the pressure relief flow path isolation safety function.
The NRC staff confirmed independently in its review of UFSAR Figure 6.4.2 that VES consists of two redundant pressure relief flow paths (VES-V022A with VES-D001A and VES-V022B with VES-D001B). Each of these flow paths can be isolated by either the valve or the damper when not relieving pressure to maintain the MCRE boundary. Based on the above, the NRC staff concludes that there is reasonable assurance that each of VES pressure relief and pressure relief path isolation function can be maintained even if the VES is inoperable due to one or more valves or dampers being inoperable VES Eductor Bypass In Section 3.1 of Enclosure to the LAR, the licensee states that:
The VES eductor bypass isolation valve (VES-V046) can be manually opened to ensure continued delivery of breathable air in the event a passive failure disables the passive filtration flow path (e.g., a filtration train blockage) after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> as assumed in the safety analysis assumptions for modeling the doses to the main control room personnel. Manually opening the eductor bypass flow path after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provides single failure protection to maintain the necessary VES breathable air safety function. The safety function is maintained either by the normally aligned passive filtration flow path or the manually actuated VES eductor bypass.
The NRC staff confirmed independently in its review of UFSAR Figure 6.4.2 that the necessary VES breathable air safety function can be maintained even if the VES is inoperable due to one or more valves or dampers being inoperable.
3.3.3 SR 3.7.6.6 The NRC staff evaluated independently the proposed wording addition to SR 3.7.6.6 that would state, except for valves that are locked, sealed, or otherwise secured in the closed position.
The proposed SR would exclude the need to verify actuation of valves that would not actuate (e.g., change position) in response to an actuation signal. The licensees LAR states, in part, that:
Placing a MCRE isolation valve in a condition not consistent with the design (i.e., locked, sealed, or otherwise secured in the closed position) requires consideration of the effect on the operability of VES or any supported systems.
As described in the proposed TS Bases changes, SNC administrative processes require assessing VES operability or any supported systems when utilizing this SR allowance. The operability assessment will consider whether there is an assumption in the safety analysis that requires movement of the affected valves or dampers following an event. SNC acknowledges that under the proposed change, the affected valve(s) may be excluded from the SR when locked, sealed or otherwise secured in the actuated position. However, if the safety analysis assumes movement from the actuated position following an event, or the system is rendered inoperable by locking, sealing, or otherwise securing the valve or damper in the actuated position, then the system cannot perform its specified safety function and is inoperable regardless of whether the SR is met.
The NRC staff finds that it is not necessary to verify actuation of valves that are already in its actuated positions, and are locked, sealed, or otherwise secured in those positions. The valves simply do not need to change state in order for the LCO to be met, and there no need to test them.
Based on the above, the NRC staff determined that the proposed revision to SR 3.7.6.6 will continue to provide reasonable assurance that LCO 3.7.6 will be met, and the revised SR therefore meetgs 10 CFR 50.36(c)(3) and is, therefore, acceptable.
4.0 STATE CONSULTATION
In accordance with the Commissions regulations, the Georgia State official was notified of the proposed issuance of the amendments on February 19, 2025. On February 20, 2025, the State official responded that they had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding published in the Federal Register on September 3, 2024 (89 FR 71437). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) there is reasonable assurance that such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: Hanry Wagage, Joshua Wilson, Nick Hansing, John Bozga, and Nicholas Soliz.
Date: February 28, 2025.
ML25052A020 NRR-058 OFFICE NRR/DORL/LPL2-1/PM NRR/DORL/LPL2-1/LA NRR/DSS/STSB/BC NRR/DSS/SCPB/BC NAME JLamb KZeleznock SMehta MValentin DATE 02/20/2025 02/21/2025 02/21/2025 02/21/2025 OFFICE NRR/DEX/EMIB/BC OGC - NLO NRR/DORL/LPL2-1/BC NRR/DORL/LPL2-1/PM NAME SBailey DRoth MMarkley JLamb DATE 02/21/2025 02/28/2025 02/28/2025 02/28/2025