ML23116A247
| ML23116A247 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 05/23/2023 |
| From: | Kimberly Green Plant Licensing Branch II |
| To: | Jim Barstow Tennessee Valley Authority |
| Green K | |
| References | |
| EPID L-2022-LLA-0192 | |
| Download: ML23116A247 (25) | |
Text
May 23, 2023 Mr. James Barstow Vice President, Nuclear Regulatory Affairs and Support Services Tennessee Valley Authority 1101 Market Street, LP 4A-C Chattanooga, TN 37402-2801
SUBJECT:
BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3 ISSUANCE OF AMENDMENT NOS. 330, 353, AND 313 REGARDING ADOPTION OF TSTF-478, REVISION 2 FOR COMBUSTIBLE GAS CONTROL (EPID L-2022-LLA-0192)
Dear Mr. Barstow:
The U.S. Nuclear Regulatory Commission (the Commission) has issued the enclosed Amendment Nos. 330, 353, and 313 to Renewed Facility Operating Licenses Nos. DPR-33, DPR-52, and DPR-68 for the Browns Ferry Nuclear Plant, Units 1, 2, and 3, respectively. These amendments are in response to your application dated December 20, 2022.
The amendments revise the Browns Ferry Nuclear Plant, Units 1, 2, and 3, Technical Specifications (TS) to delete TS 3.6.3.1, Containment Atmosphere Dilution (CAD) System, and the associated TS Bases. The revisions are consistent with Revision 2 to TSTF Traveler, TSTF-478-A, BWR [Boiling Water Reactor] Technical Specification Changes that Implement the Revised Rule for Combustible Gas Control.
J. Barstow A copy of the Safety Evaluation is also enclosed. A Notice of Issuance will be included in the Commissions monthly Federal Register notice.
Sincerely,
/RA/
Kimberly J. Green, Senior Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-259, 50-260, and 50-296
Enclosures:
- 1. Amendment No. 330 to DPR-33
- 2. Amendment No. 353 to DPR-52
- 3. Amendment No. 313 to DPR-68
- 4. Safety Evaluation cc: Listserv
TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-259 BROWNS FERRY NUCLEAR PLANT UNIT 1 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 330 Renewed License No. DPR-33
- 1. The U.S. Nuclear Regulatory Commission (the Commission) has found that:
A. The application for amendment by the Tennessee Valley Authority (the licensee) dated December 20, 2022, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in Title 10 of the Code of Federal Regulations (10 CFR)
Chapter I; B. The facility 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 to 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.
Enclosure 1
- 2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment and paragraph 2.C.(2) of Renewed Facility Operating License No. DPR-33 is hereby amended to read as follows:
(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 330, are hereby incorporated in the renewed operating license. The licensee shall operate the facility in accordance with the Technical Specifications.
- 3. This license amendment is effective as of its date of issuance and shall be implemented within 90 days from the date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION Digitally signed by David David J. J. Wrona Date: 2023.05.23 Wrona 16:21:10 -04'00' David J. Wrona, Chief Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Attachment:
Changes to the Technical Specifications and Renewed Facility Operating License Date of Issuance: May 23, 2023
ATTACHMENT TO LICENSE AMENDMENT NO. 330 RENEWED FACILITY OPERATING LICENSE NO. DPR-33 BROWNS FERRY NUCLEAR PLANT, UNIT 1 DOCKET NO. 50-259 Replace the following pages of the Renewed Facility Operating License and Appendix A, Technical Specifications (TSs), with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.
Remove Insert License DPR-33 License DPR-33 Page 3 Page 3 TSs TSs 3.6-40 3.6-40 3.6-41 3.6-41
(3) Pursuant to the Act and 10 CFR Parts 30, 40, and 70, to receive, possess, and use at any time any byproduct, source, and special nuclear material as sealed neutron sources for reactor startup, sealed sources for reactor instrumentation and radiation monitoring equipment calibration, and as fission detectors in amounts as required; (4) Pursuant to the Act and 10 CFR Parts 30, 40, and 70, to receive, possess, and use in amounts as required any byproduct, source, or special nuclear material without restriction to chemical or physical form for sample analysis or equipment and instrument calibration or associated with radioactive apparatus or components; (5) Pursuant to the Act and 10 CFR Parts 30 and 70, to possess but not separate, such byproduct and special nuclear materials as may be produced by the operation of the facility.
C. This renewed operating license shall be deemed to contain and is subject to the conditions specified in the following Commission regulations in 10 CFR Chapter I:
Part 20, Section 30.34 of Part 30, Section 40.41 of Part 40, Sections 50.54 and 50.59 of Part 50, and Section 70.32 of Part 70; is subject to all applicable provisions of the Act and to the rules, regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified or incorporated below:
(1) Maximum Power Level The licensee is authorized to operate the facility at steady state reactor core power levels not in excess of 3952 megawatts thermal.
(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 330, are hereby incorporated in the renewed operating license. The licensee shall operate the facility in accordance with the Technical Specifications.
For Surveillance Requirements (SRs) that are new in Amendment 234 to Facility Operating License DPR-33, the first performance is due at the end of the first surveillance interval that begins at implementation of the Amendment 234. For SRs that existed prior to Amendment 234, including SRs with modified acceptance criteria and SRs whose frequency of performance is being extended, the first performance is due at the end of the first surveillance interval that begins on the date the surveillance was last performed prior to implementation of Amendment 234.
BFN-UNIT 1 Renewed License No. DPR-33 Amendment No. 330
CAD System 3.6.3.1 3.6 CONTAINMENT SYSTEMS 3.6.3.1 Containment Atmosphere Dilution (CAD) System (Deleted)
BFN-UNIT 1 3.6-40 Amendment No. 234, 249, 255,
CAD System 3.6.3.1 This page intentionally left blank.
BFN-UNIT 1 3.6-41 Amendment No. 234, 299, 315,
TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-260 BROWNS FERRY NUCLEAR PLANT, UNIT 2 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 353 Renewed License No. DPR-52
- 1. The U.S. Nuclear Regulatory Commission (the Commission) has found that:
A. The application for amendment by Tennessee Valley Authority (the licensee) dated December 20, 2022, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in Title 10 of the Code of Federal Regulations (10 CFR)
Chapter I; B. The facility 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 Commission's regulations; D. The issuance of this amendment will not be inimical to the common defense and security or to 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.
Enclosure 2
- 2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment and paragraph 2.C.(2) of Renewed Facility Operating License No. DPR-52 is hereby amended to read as follows:
(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 353, are hereby incorporated in the renewed operating license. The licensee shall operate the facility in accordance with the Technical Specifications.
- 3. This license amendment is effective as of its date of issuance and shall be implemented within 90 days from the date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION Digitally signed by David David J. J. Wrona Date: 2023.05.23 Wrona 16:24:26 -04'00' David J. Wrona, Chief Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Attachment:
Changes to the Technical Specifications and Renewed Facility Operating License Date of Issuance: May 23, 2023
ATTACHMENT TO LICENSE AMENDMENT NO. 353 RENEWED FACILITY OPERATING LICENSE NO. DPR-52 BROWNS FERRY NUCLEAR PLANT, UNIT 2 DOCKET NO. 50-260 Replace the following pages of the Renewed Facility Operating License and Appendix A, Technical Specifications (TSs), with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.
Remove Insert License DPR-52 License DPR-52 Page 3 Page 3 TSs TSs 3.6-40 3.6-40 3.6-41 3.6-41
sealed neutron sources for reactor startup, sealed sources for reactor instrumentation and radiation monitoring equipment calibration, and as fission detectors in amounts as required; (4) Pursuant to the Act and 10 CFR Parts 30, 40, and 70, to receive, possess, and use in amounts as required any byproduct, source, or special nuclear material without restriction to chemical or physical form for sample analysis or equipment and instrument calibration or associated with radioactive apparatus or components; (5) Pursuant to the Act and 10 CFR Parts 30 and 70, to possess but not separate, such byproduct and special nuclear materials as may be produced by the operation of the facility.
C. This renewed operating license shall be deemed to contain and is subject to the conditions specified in the following Commission regulations in 10 CFR Chapter I:
Part 20, Section 30.34 of Part 30, Section 40.41 of Part 40, Sections 50.54 and 50.59 of Part 50, and Section 70.32 of Part 70; is subject to all applicable provisions of the Act and to the rules, regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified or incorporated below:
(1) Maximum Power Level The licensee is authorized to operate the facility at steady state reactor core power levels not in excess of 3952 megawatts thermal.
(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 353, are hereby incorporated in the renewed operating license. The licensee shall operate the facility in accordance with the Technical Specifications.
For Surveillance Requirements (SRs) that are new in Amendment 253 to Facility Operating License DPR-52, the first performance is due at the end of the first surveillance interval that begins at implementation of the Amendment 253. For SRs that existed prior to Amendment 253, including SRs with modified acceptance criteria and SRs whose frequency of performance is being extended, the first performance is due at the end of the first surveillance interval that begins on the date the surveillance was last performed prior to implementation of Amendment 253.
- 3) The licensee is authorized to relocate certain requirements included in Appendix A and the former Appendix B to licensee-controlled documents.
Implementation of this amendment shall include the relocation of these requirements to the appropriate documents, as described in the licensee's BFN-UNIT 2 Renewed License No. DPR-52 Amendment No. 353
CAD System 3.6.3.1 3.6 CONTAINMENT SYSTEMS 3.6.3.1 Containment Atmosphere Dilution (CAD) System (Deleted)
BFN-UNIT 2 3.6-40 Amendment No. 253, 265, 286,
CAD System 3.6.3.1 This page intentionally left blank.
BFN-UNIT 2 3.6-41 Amendment No. 253, 323, 338,
TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-296 BROWNS FERRY NUCLEAR PLANT, UNIT 3 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 313 Renewed License No. DPR-68
- 1. The U.S. Nuclear Regulatory Commission (the Commission) has found that:
A. The application for amendment by Tennessee Valley Authority (the licensee) dated December 20, 2022, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in Title 10 of the Code of Federal Regulations (10 CFR)
Chapter I; B. The facility 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 to 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.
Enclosure 3
- 2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment and paragraph 2.C.(2) of Renewed Facility Operating License No. DPR-68 is hereby amended to read as follows:
(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 313, are hereby incorporated in the renewed operating license. The licensee shall operate the facility in accordance with the Technical Specifications.
- 3. This license amendment is effective as of its date of issuance and shall be implemented within 90 days from the date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION Digitally signed by David David J. J. Wrona Date: 2023.05.23 Wrona 16:27:10 -04'00' David J. Wrona, Chief Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Attachment:
Changes to the Technical Specifications and Renewed Facility Operating License Date of Issuance: May 23, 2023
ATTACHMENT TO LICENSE AMENDMENT NO. 313 RENEWED FACILITY OPERATING LICENSE NO. DPR-68 BROWNS FERRY NUCLEAR PLANT, UNIT 3 DOCKET NO. 50-296 Replace the following pages of the Renewed Facility Operating License and Appendix A, Technical Specifications (TSs), with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.
Remove Insert License DPR-68 License DPR-68 Page 3 Page 3 TSs TSs 3.6-40 3.6-40 3.6-41 3.6-41
(3) Pursuant to the Act and 10 CFR Parts 30, 40, and 70, to receive, possess, and use at any time any byproduct, source, and special nuclear material as sealed neutron sources for reactor startup, sealed sources for reactor instrumentation and radiation monitoring equipment calibration, and as fission detectors in amounts as required; (4) Pursuant to the Act and 10 CFR Parts 30, 40, and 70, to receive, possess, and use in amounts as required any byproduct, source, or special nuclear material without restriction to chemical or physical form for sample analysis or equipment and instrument calibration or associated with radioactive apparatus or components; (5) Pursuant to the Act and 10 CFR Parts 30 and 70, to possess but not separate, such byproduct and special nuclear materials as may be produced by the operation of the facility.
C. This renewed operating license shall be deemed to contain and is subject to the conditions specified in the following Commission regulations in 10 CFR Chapter I:
Part 20, Section 30.34 of Part 30, Section 40.41 of Part 40, Sections 50.54 and 50.59 of Part 50, and Section 70.32 of Part 70; is subject to all applicable provisions of the Act and to the rules, regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified or incorporated below:
(1) Maximum Power Level The licensee is authorized to operate the facility at steady state reactor core power levels not in excess of 3952 megawatts thermal.
(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 313, are hereby incorporated in the renewed operating license. The licensee shall operate the facility in accordance with the Technical Specifications.
For Surveillance Requirements (SRs) that are new in Amendment 212 to Facility Operating License DPR-68, the first performance is due at the end of the first surveillance interval that begins at implementation of the Amendment 212. For SRs that existed prior to Amendment 212, including SRs with modified acceptance criteria and SRs whose frequency of performance is being extended, the first performance is due at the end of the first surveillance interval that begins on the date the surveillance was last performed prior to implementation of Amendment 212.
BFN-UNIT 3 Renewed License No. DPR-68 Amendment No. 313
CAD System 3.6.3.1 3.6 CONTAINMENT SYSTEMS 3.6.3.1 Containment Atmosphere Dilution (CAD) System (Deleted)
BFN-UNIT 3 3.6-40 Amendment No. 212, 225, 244,
CAD System 3.6.3.1 This page intentionally left blank.
BFN-UNIT 3 3.6-41 Amendment No. 212, 283, 298,
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 330, 353, AND 313 TO RENEWED FACILITY OPERATING LICENSE NOS. DPR-33, DPR-52, AND DPR-68 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3 DOCKET NOS. 50-259, 50-260, AND 50-296
1.0 INTRODUCTION
By letter dated December 20, 2022 (Agencywide Documents Access and Management System Accession No. ML22354A111), the Tennessee Valley Authority (TVA, the licensee) submitted a license amendment request (LAR) to the U.S. Nuclear Regulatory Commission (NRC or the Commission) to revise the Browns Ferry Nuclear Plant (Browns Ferry), Units 1, 2, and 3 technical specifications (TSs).
The proposed change would delete TS 3.6.3.1, Containment Atmosphere Dilution (CAD)
System, and the associated TS Bases. The licensee developed the proposed change based upon NRC-approved Revision 2 to Technical Specifications Task Force (TSTF) Traveler TSTF-478, BWR [Boiling-Water Reactor] Technical Specification Changes that Implement the Revised Rule for Combustible Gas Control (ML071920140). The TSTF Traveler modifies containment combustible gas control requirements as permitted by Section 50.44, Combustible gas control for nuclear power reactors, of Title 10 of the Code of Federal Regulations (10 CFR).
The availability of this TS improvement was announced in the Federal Register on November 21, 2007 (72 FR 65610) (ML073170138), as part of the consolidated line item improvement process (CLIIP).
Throughout the application, the licensee refers to TSTF-478-A as a basis for the requested amendment. The NRC staff notes that the -A designation added to TSTF-478 is an industry convention used to indicate that the traveler has been approved by the NRC. TSTF-478 and TSTF-478-A are the same document. However, since TSTF-478-A is not an NRC designation, this safety evaluation (SE) refers to the TS change traveler as TSTF-478.
The licensee stated that the application is consistent with NRC-approved Revision 2 to TSTF-478. Proposed revisions to the TS Bases are also included in this LAR. The licensee stated that adoption of the TS Bases associated with TSTF-478, Revision 2, is an integral part of implementing the TS amendment and that the changes to the affected TS Bases pages will be incorporated in accordance with the TS Bases Control Program.
Enclosure 4
This application is being made in accordance with the CLIIP. TVA proposed two variations from the TS changes described in TSTF-478, Revision 2, and the NRC staff's model SE published on November 21, 2007 (72 FR 65610), as part of the CLIIP Notice of Availability. First, the Browns Ferry, Units 1, 2, and 3, TS for the CAD system is numbered TS 3.6.3.1 rather than TS 3.6.3.3 as provided in the TSTF-478 mark-ups. Second, TSTF-478, Revision 2, also makes TS and Bases changes to the TS section on drywell cooling system fans. The Browns Ferry, Units 1, 2, and 3 TSs do not include a TS section on drywell cooling system fans; therefore, these changes are not needed.
2.0 REGULATORY EVALUATION
2.1 Containment Atmosphere Dilution System The design purpose of the CAD system is to maintain combustible gas concentrations within the primary containment at or below the flammability limits following a postulated loss-of-coolant accident (LOCA) by diluting hydrogen and oxygen with the addition of nitrogen. The CAD system, however, is considered ineffective at mitigating hydrogen releases from the more risk significant beyond design-basis accidents that could threaten primary containment integrity. The revised 10 CFR 50.44 rule requires systems and measures be in place to reduce the risks associated with combustible gases from beyond design-basis accidents and eliminates requirements for maintaining hydrogen and oxygen control equipment associated with a design-basis LOCA. As a result, the CAD system is no longer a mitigating safety system required to be maintained per the revised 10 CFR 50.44 rule. Technical Specification 3.6.3.1, Containment Atmosphere Dilution (CAD) System, can therefore be deleted, and the technical basis for allowing the deletion is found in Section 3.0 of this SE.
2.2 Regulatory Review General Design Criterion (GDC) 41, Containment atmosphere cleanup, of Appendix A to 10 CFR Part 50 requires, in part, that systems to control fission products, hydrogen, oxygen, and other substances that may be released into the reactor containment shall be provided as necessary to reduce the concentration and quality of fission products and control the concentration of hydrogen, oxygen, and other substances in the containment atmosphere following postulated accidents to assure that containment integrity is maintained. The regulations in 10 CFR 50.44, Combustible gas control for nuclear power reactors, provides, among other things, standards for controlling combustible gas that may accumulate in the containment atmosphere during accidents.
The NRC staff notes that the Browns Ferry units were designed and constructed based on the proposed GDC (PDC) published by the Atomic Energy Commission (AEC) on July 11, 1967.
Appendix A of the Browns Ferry Updated Final Safety Analysis Report (UFSAR)
(ML21286A200) identifies the AEC PDC and the UFSAR sections that describe the plants conformance to the PDC.
The regulations in 10 CFR 50.44 were revised on September 16, 2003 (68 FR 54123), as a result of studies that led to an improved understanding of combustible gas behavior during severe accidents. The studies confirmed that the hydrogen release postulated from a design-basis loss-of-coolant accident (LOCA) was not risk significant because it was not large enough to lead to early containment failure, and that the risk associated with hydrogen combustion was from beyond design-basis (i.e., severe) accidents. As a result, requirements for maintaining hydrogen control equipment associated with a design-basis LOCA were eliminated
from 10 CFR 50.44. Regulatory Guide 1.7, Control of Combustible Gas Concentrations in Containment, Revision 3, dated March 2007 (ML070290080), provides detailed guidance that would be acceptable for implementing 10 CFR 50.44.
Section 182a of the Atomic Energy Act, as amended requires applicants for nuclear power plant operating licenses to include TS as part of the license application. The TS, among other things, help to ensure the operational capability of structures, systems, and components that are required to protect the health and safety of the public. The NRCs regulatory requirements related to the content of the TS are contained in 10 CFR 50.36, which requires that the TS include items in the following categories: (1) safety limits, limiting safety systems settings, and limiting control settings; (2) limiting conditions for operation; (3) surveillance requirements; (4) design features; and (5) administrative controls. The regulations in 10 CFR 50.36(c)(2)(i) state, in part, that limiting conditions for operation are the lowest functional capability or performance levels of equipment required for safe operation of the facility. When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the technical specifications until the condition can be met. TSTF-478, Revision 2 contains changes to remedial actions permitted by the TS.
3.0 TECHNICAL EVALUATION
3.1 Containment Atmosphere Dilution System BWRs with Mark I containment designs have either installed hydrogen recombiners or CAD systems to meet requirements for combustible gas control following a design-basis LOCA. The hydrogen recombiners and the CAD system perform similar functions for post-LOCA gas control by decreasing the hydrogen concentration. Hydrogen recombiners function to reduce the combustible gas concentration in the primary containment by recombining hydrogen and oxygen to form water vapor. The CAD system functions to maintain combustible gas concentrations within the primary containment at or below the flammability limits following a postulated LOCA by diluting hydrogen and oxygen by adding nitrogen to the mixture. In the case of Browns Ferry, a CAD system is installed as part of a containment atmospheric control system. There are no installed hydrogen recombiners.
Studies performed in support of the 10 CFR 50.44 rule change (September 16, 2003; 68 FR 54123) confirmed that the hydrogen release postulated from a design-basis LOCA was not risk significant because it was not large enough to lead to early containment failure, and that the risk associated with hydrogen combustion was from beyond design-basis (i.e., severe) accidents. As a result, the revised 10 CFR 50.44 rule eliminates requirements for maintaining hydrogen control equipment associated with a design-basis LOCA and requires systems and measures be in place to reduce the risks associated with hydrogen combustion from beyond design-basis accidents.
The CAD system maintains combustible gas concentrations within the primary containment at or below the flammability limits following a LOCA; however, this system, as discussed in the 10 CFR 50.44 rule change was shown to be ineffective at mitigating hydrogen releases from the more risk significant beyond design-basis accidents that could threaten primary containment integrity, and is no longer required to address a design-basis LOCA. Therefore, the NRC staff finds that the deletion of Browns Ferry, Units 1, 2 and 3 TS 3.6.3.1, Containment Atmosphere Dilution (CAD) System, is acceptable.
3.2 Variations The licensee proposed variations are described in Section 1.0 of this SE. The NRC staff finds these variations are acceptable because the variations do not substantively alter any TS requirements.
4.0 STATE CONSULTATION
In accordance with the Commissions regulations, the Alabama State official was notified of the proposed issuance of the amendments on April 13, 2023. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and change surveillance requirements. The NRC staff has determined that the amendments involve 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 NRC has previously issued a proposed finding that the amendments involve no significant hazards consideration in the Federal Register on February 21, 2023 (88 FR 10558), and there has been no public comment on such finding.
Accordingly, the amendments meet 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 amendments.
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 amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: C. Ashley, NRR Date: May 23, 2023
ML23116A247 OFFICE NRR/DORL/LPLII-2/PM NRR/DORL/LPLII-2/LA NRR/DSS/STSB/BC NAME KGreen RButler VCusumano DATE 04/26/23 05/03/23 04/13/23 OFFICE NRR/DORL/LPLII-2/BC NRR/DORL/LPLII-2/PM NAME DWrona KGreen DATE 05/23/23 05/23/23