ML24145A178

Issuance of Amendment Nos. 430, 432, and 431, to TS 5.5.2, Containment Leakage Rate Testing Program for a one-time Extension of the Type a Leak Rate Test Frequency

ML24145A178
Person / Time
Site:	Oconee
Issue date:	08/26/2024
From:	Shawn Williams Plant Licensing Branch II
To:	Snider S Duke Energy Carolinas
Williams S
References
EPID L-2023-LLA-0162
Download: ML24145A178 (1)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 August 26, 2024 Steven M. Snider Vice President, Oconee Nuclear Station Duke Energy Carolinas, LLC 7800 Rochester Highway Seneca, SC 29672-0752

SUBJECT:

OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3 ISSUANCE OF AMENDMENT NOS. 430, 432 AND 431, TO TECHNICAL SPECIFICATION 5.5.2, CONTAINMENT LEAKAGE RATE TESTING PROGRAM FOR A ONE-TIME EXTENSION OF THE UNITS 1,2, AND 3 TYPE A LEAK RATE TEST FREQUENCY (EPID L-2023-LLA-0162)

Dear Steven M. Snider:

The U.S. Nuclear Regulatory Commission has issued the enclosed Amendment Nos. 430, 432, and 431 to Renewed Facility Operating Licenses DPR-38, DPR-47, and DPR-55, for the Oconee Nuclear Station, Units 1, 2, and 3, respectively. The amendments are in response to the application from Duke Energy Carolinas, LLC, dated November 16, 2023, as supplemented by letter dated April 19, 2024.

The amendments revise Technical Specification (TS) 5.5.2, Containment Leakage Rate Testing Program, by allowing a one-time extension to the 10-year frequency of the containment integrated leakage rate test (ILRT or Type A test). The amendments permit the existing ILRT frequency to be extended from 10 years to approximately 12 years for all three Oconee units.

A copy of the related Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commissions monthly Federal Register notice.

S. Snider If you have any questions, please call me at 301-415-1009, or by email at Shawn.Williams@nrc.gov.

Sincerely,

/RA/

Shawn A. Williams, Senior Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-269, 50-270, and 50-287

Enclosures:

1. Amendment No. 430 to DPR-38

2. Amendment No. 432 to DPR-47

3. Amendment No. 431 to DPR-55

4. Safety Evaluation cc: Listserv

ML24145A178 OFFICE NRR/DORL/LPL2-1/PM NRR/DORL/LPL2-1/LA NRR/DSS/SCPB/BC NAME JMinzerBryant KGoldstein MValentin DATE 06/21/2024 08/14/2024 06/12/2024 OFFICE NRR/DSS/STSB/BC NRR/DEX/EMIB/BC NRR/DEX/ESEB/BC NAME SMehta SBailey ITseng DATE 07/01/2024 07/03/2024 06/24/2024 OFFICE NRR/DNRL/NCSG/BC OGC/NLO NRR/DORL/LPL2-1/BC NAME SBloom KBernstein MMarkley DATE 06/24/2024 8/9/2024 08/26/2024 OFFICE NRR/DORL/LPL2-1/PM NAME SWilliams DATE 08/26/2024

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 DUKE ENERGY CAROLINAS, LLC DOCKET NO. 50-269 OCONEE NUCLEAR STATION, UNIT 1 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 430 Renewed License No. DPR-38

1.

The Nuclear Regulatory Commission (NRC, the Commission) has found that:

A.

The application for amendment to the Oconee Nuclear Station, Unit 1 (the facility), Renewed Facility Operating License No. DPR-38, filed by Duke Energy Carolinas, LLC (the licensee), dated November 16, 2023, as supplemented by letter dated April 19, 2024, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations as set forth in 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.

2.

Accordingly, the license is hereby amended by page changes to the Renewed Facility Operating License and Technical Specifications as indicated in the attachment to this license amendment, and Paragraph 3.B of Renewed Facility Operating License No.

DPR-38 is hereby amended to read as follows:

B.

Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 430, are hereby incorporated in the 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 30 days of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION Michael T. Markley, Chief Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to Renewed Facility Operating License No. DPR-38 and the Technical Specifications Date of Issuance: August 26, 2024 MICHAEL MARKLEY Digitally signed by MICHAEL MARKLEY Date: 2024.08.26 17:26:35 -04'00'

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 DUKE ENERGY CAROLINAS, LLC DOCKET NO. 50-270 OCONEE NUCLEAR STATION, UNIT 2 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 432 Renewed License No. DPR-47

1.

The Nuclear Regulatory Commission (NRC, the Commission) has found that:

A.

The application for amendment to the Oconee Nuclear Station, Unit 2 (the facility), Renewed Facility Operating License No. DPR-47, filed by Duke Energy Carolinas, LLC (the licensee), dated November 16, 2023, as supplemented by letter dated April 19, 2024, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations as set forth in 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.

2.

Accordingly, the license is hereby amended by page changes to the Renewed Facility Operating License and Technical Specifications as indicated in the attachment to this license amendment, and Paragraph 3.B of Renewed Facility Operating License No.

DPR-47 is hereby amended to read as follows:

B.

Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 432, are hereby incorporated in the 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 30 days of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION Michael T. Markley, Chief Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to Renewed Facility Operating License No. DPR-47 and the Technical Specifications Date of Issuance: August 26, 2024 MICHAEL MARKLEY Digitally signed by MICHAEL MARKLEY Date: 2024.08.26 17:27:30 -04'00'

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 DUKE ENERGY CAROLINAS, LLC DOCKET NO. 50-287 OCONEE NUCLEAR STATION, UNIT 3 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 431 Renewed License No. DPR-55

1.

The Nuclear Regulatory Commission (NRC, the Commission) has found that:

A.

The application for amendment to the Oconee Nuclear Station, Unit 3 (the facility), Renewed Facility Operating License No. DPR-55, filed by Duke Energy Carolinas, LLC (the licensee), November 16, 2023, as supplemented by letter dated April 19, 2024, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations as set forth in 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 Commission's regulations and all applicable requirements have been satisfied.

2.

Accordingly, the license is hereby amended by page changes to the Renewed Facility Operating License and Technical Specifications as indicated in the attachment to this license amendment, and Paragraph 3.B of Renewed Facility Operating License No.

DPR-55 is hereby amended to read as follows:

B.

Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 431, are hereby incorporated in the 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 30 days of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION Michael T. Markley, Chief Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to Renewed Facility Operating License No. DPR-55 and the Technical Specifications Date of Issuance: August 26, 2024 MICHAEL MARKLEY Digitally signed by MICHAEL MARKLEY Date: 2024.08.26 17:28:22 -04'00'

ATTACHMENT TO AMENDMENT NO. 430 RENEWED FACILITY OPERATING LICENSE NO. DPR-38 AMENDMENT NO. 432 RENEWED FACILITY OPERATING LICENSE NO. DPR-47 AMENDMENT NO. 431 RENEWED FACILITY OPERATING LICENSE NO. DPR-55 OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3 DOCKET NOS. 50-269, 50-270, AND 50-287 Replace the following pages of the Operating Licenses and the Appendix A Technical Specifications with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.

Remove Pages Insert Pages Operating Licenses Operating Licenses License No. DPR-38, page 3 License No. DPR-38, page 3 License No. DPR-47, page 3 License No. DPR-47, page 3 License No. DPR-55, page 3 License No. DPR-55, page 3 Technical Specifications Technical Specifications 5.0-7 5.0-7 5.0-8 5.0-8 Renewed License No. DPR-38 Amendment No. 430 A.

Maximum Power Level The licensee is authorized to operate the facility at steady state reactor core power levels not in excess of 2610 megawatts thermal.

B.

Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 430 are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

C.

This license is subject to the following antitrust conditions:

Applicant makes the commitments contained herein, recognizing that bulk power supply arrangements between neighboring entities normally tend to serve the public interest. In addition, where there are net benefits to all participants, such arrangements also serve the best interests of each of the participants. Among the benefits of such transactions are increased electric system reliability, a reduction in the cost of electric power, and minimization of the environmental effects of the production and sale of electricity.

Any particular bulk power supply transaction may afford greater benefits to one participant than to another. The benefits realized by a small system may be proportionately greater than those realized by a larger system. The relative benefits to be derived by the parties from a proposed transaction, however, should not be controlling upon a decision with respect to the desirability of participating in the transaction. Accordingly, applicant will enter into proposed bulk power transactions of the types hereinafter described which, on balance, provide net benefits to applicant. There are net benefits in a transaction if applicant recovers the cost of the transaction (as defined in ¶1 (d) hereof) and there is no demonstrable net detriment to applicant arising from that transaction.

1.

As used herein:

(a)

Bulk Power means electric power and any attendant energy, supplied or made available at transmission or sub-transmission voltage by one electric system to another.

(b)

Neighboring Entity means a private or public corporation, a governmental agency or authority, a municipality, a cooperative, or a lawful association of any of the foregoing owning or operating, or proposing to own or operate, facilities for the generation and transmission of electricity which meets each of Renewed License No. DPR-47 Amendment No. 432 A.

Maximum Power Level The licensee is authorized to operate the facility at steady state reactor core power levels not in excess of 2610 megawatts thermal.

B.

Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 432 are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

C.

This license is subject to the following antitrust conditions:

Applicant makes the commitments contained herein, recognizing that bulk power supply arrangements between neighboring entities normally tend to serve the public interest. In addition, where there are net benefits to all participants, such arrangements also serve the best interests of each of the participants. Among the benefits of such transactions are increased electric system reliability, a reduction in the cost of electric power, and minimization of the environmental effects of the production and sale of electricity.

Any particular bulk power supply transaction may afford greater benefits to one participant than to another. The benefits realized by a small system may be proportionately greater than those realized by a larger system. The relative benefits to be derived by the parties from a proposed transaction, however, should not be controlling upon a decision with respect to the desirability of participating in the transaction. Accordingly, applicant will enter into proposed bulk power transactions of the types hereinafter described which, on balance, provide net benefits to applicant. There are net benefits in a transaction if applicant recovers the cost of the transaction (as defined in ¶1 (d) hereof) and there is no demonstrable net detriment to applicant arising from that transaction.

1.

As used herein:

(a)

Bulk Power means electric power and any attendant energy, supplied or made available at transmission or sub-transmission voltage by one electric system to another.

(b)

Neighboring Entity means a private or public corporation, a governmental agency or authority, a municipality, a cooperative, or a lawful association of any of the foregoing owning or operating, or proposing to own or operate, facilities for the generation and transmission of electricity which meets each of Renewed License No. DPR-55 Amendment No. 431 A. Maximum Power Level The licensee is authorized to operate the facility at steady state reactor core power levels not in excess of 2610 megawatts thermal.

B.

Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 431 are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

C.

This license is subject to the following antitrust conditions:

Applicant makes the commitments contained herein, recognizing that bulk power supply arrangements between neighboring entities normally tend to serve the public interest. In addition, where there are net benefits to all participants, such arrangements also serve the best interests of each of the participants. Among the benefits of such transactions are increased electric system reliability, a reduction in the cost of electric power, and minimization of the environmental effects of the production and sale of electricity.

Any particular bulk power supply transaction may afford greater benefits to one participant than to another. The benefits realized by a small system may be proportionately greater than those realized by a larger system. The relative benefits to be derived by the parties from a proposed transaction, however, should not be controlling upon a decision with respect to the desirability of participating in the transaction. Accordingly, applicant will enter into proposed bulk power transactions of the types hereinafter described which, on balance, provide net benefits to applicant. There are net benefits in a transaction if applicant recovers the cost of the transaction (as defined in ¶1 (d) hereof) and there is no demonstrable net detriment to applicant arising from that transaction.

1. As used herein:

(a)

Bulk Power means electric power and any attendant energy, supplied or made available at transmission or sub-transmission voltage by one electric system to another.

(b)

Neighboring Entity means a private or public corporation, a governmental agency or authority, a municipality, a cooperative, or a lawful association of any of the foregoing owning or operating, or proposing to own or operate, facilities for the generation and transmission of electricity which meets each of

OCONEE UNITS 1, 2, & 3 5.0-7 Amendment Nos. 430, 432, & 431 Programs and Manuals 5.5 5.0 ADMINISTRATIVE CONTROLS 5.5 Programs and Manuals The following programs shall be established, implemented, and maintained.

5.5.1 Offsite Dose Calculation Manual (ODCM)

The ODCM shall contain the methodology and parameters used in the calculation of offsite doses resulting from radioactive gaseous and liquid effluents, in the calculation of gaseous and liquid effluent monitoring alarm and trip setpoints, and in the conduct of the radiological environmental monitoring program.

Licensee initiated changes to the ODCM:

a.

Shall be documented and records of reviews performed shall be retained.

This documentation shall contain:

1.

sufficient information to support the change(s) together with the appropriate analyses or evaluations justifying the change(s), and

2.

a determination that the change(s) do not adversely impact the accuracy or reliability of effluent, dose, or setpoint calculations;

b.

Shall become effective after the approval of the Plant Manager or Radiation Protection Manager; and

c.

Shall be submitted to the NRC in the form of a complete, legible copy of the entire ODCM as a part of or concurrent with the Radioactive Effluent Release Report for the period of the report in which any change in the ODCM was made. Each change shall be identified by markings in the margin of the affected pages, clearly indicating the area of the page that was changed, and shall indicate the date (i.e., month and year) the change was implemented.

5.5.2 Containment Leakage Rate Testing Program A program shall establish the leakage rate testing of the containment as required by 10 CFR 50.54(o) and 10 CFR 50, Appendix J, Option B, as modified by approved exemptions. The next Unit 1 ILRT following the November 29, 2014 test shall be performed no later than November 29, 2026. The next Unit 2 ILRT following the November 7, 2015 test shall be performed no later than November 28, 2027. The next Unit 3 ILRT following the May 10, 2016 test shall be performed no later than May 25, 2028. This program shall be in accordance with the guidelines contained in Regulatory Guide 1.163, Performance-Based

Programs and Manuals 5.5 5.5 Programs and Manuals OCONEE UNITS 1, 2, & 3 5.0-8 Amendment Nos. 430, 432, & 431 Containment Leak-Test Program, dated September 1995. Containment system visual examinations required by Regulatory Guide 1.163, Regulatory Position C.3 shall be performed as follows:

1.

Accessible concrete surfaces and post-tensioning system component surfaces of the concrete containment shall be visually examined prior to initiating SR 3.6.1.1 Type A test. These visual examinations, or any portion thereof, shall be performed no earlier than 90 days prior to the start of refueling outages in which Type A tests will be performed. The validity of these visual examinations will be evaluated should any event or condition capable of affecting the integrity of the containment system occur between the completion of the visual examinations and the Type A test.

2.

Accessible interior and exterior surfaces of metallic pressure retaining components of the containment system shall be visually examined at least three times every ten years, including during each shutdown for SR 3.6.1.1 Type A test, prior to initiating the Type A test.

The calculated peak containment internal pressure for the design basis loss of coolant accident, Pa, is 59 psig. The containment design pressure is 59 psig.

The maximum allowable containment leakage rate, La, at Pa, shall be 0.20% of the containment air weight per day.

Leakage rate acceptance criterion is:

a.

Containment leakage rate acceptance criterion is 1.0 La. During the first unit startup following testing in accordance with this program, the leakage rate acceptance criteria are 0.60 La for the Type B and C tests, and 0.75 La for Type A tests; The provisions of SR 3.0.3 are applicable to the Containment Leakage Rate Testing Program.

Nothing in these Technical Specifications shall be construed to modify the testing Frequencies of 10 CFR 50, Appendix J.

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 430 TO RENEWED FACILITY OPERATING LICENSE NO. DPR-38 AMENDMENT NO. 432 TO RENEWED FACILITY OPERATING LICENSE NO. DPR-47 AMENDMENT NO. 431 TO RENEWED FACILITY OPERATING LICENSE NO. DPR-55 DUKE ENERGY CAROLINAS, LLC OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3 DOCKET NOS. 50-269, 50-270, AND 50-287

1.0 INTRODUCTION

By application dated November 16, 2023 (Agencywide Documents Access and Management System Accession No. ML23320A111), as supplemented by letter dated April 19, 2024 (ML24110A112), Duke Energy Carolinas, LLC (Duke Energy or the licensee) requested changes to the Technical Specifications (TS) for the Oconee Nuclear Station Units 1, 2, and 3 (Oconee Units 1,2, and 3). The proposed changes would revise Oconee TS 5.5.2, Containment Leakage Rate Testing Program, to allow for a one-time extension to the 10-year frequency of the Oconee Type A containment integrated leakage rate test (ILRT). Specifically, the proposed change would permit the existing ILRT frequency to be extended from 10 years to approximately 12 years for all three Oconee units.

The supplement dated April 19, 2024, provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the U.S. Nuclear Regulatory Commission (NRC or the Commission) staffs original proposed no significant hazards consideration determination as published in the Federal Register (FR)

January 23, 2024 (89 FR 4342).

2.0 REGULATORY EVALUATION

2.1

System Description

The primary containment system at Oconee called the reactor building (RB), and consists of the RB structure, its steel liner, and the penetrations of the liner and structure. The RB encloses the components of the reactor coolant pressure boundary and serves to prevent the release of radioactivity to the environment in the event of an accident condition. As described in Oconees Updated Final Safety Analysis Report (UFSAR), Revision 29 (ML22180A123) Section 3.8, Design of Structures, and Section 6.2, Containment Systems, the containment is designed to permit leakage monitoring during the life of the plant.

A program of testing and surveillance of the reactor building has been developed to provide assurance, during service, of the capability of each containment system to perform its intended safety function. This program consists of the following tests:

(1) overall integrated leak rate tests of the reactor building; (2) local leak detection tests of the components having resilient seals, gaskets, or sealant compounds that penetrate or seal the boundary of the containment system; (3) local leak detection and operability tests of containment isolation valves in systems that vent directly to the reactor building atmosphere or the reactor coolant system that must close upon receiving an isolation signal and seal the containment under accident conditions; and (4) operability tests of engineered safeguards systems which under post-accident conditions are relied upon to limit or reduce leakage from containment.

2.2 Licensees Proposed Changes The proposed change to Oconee TS Chapter 5.0, Administrative Controls, Section 5.5.2 will revise the dates for the next required ILRT for each of the three units, by increasing the current 10-year ILRT frequency to a maximum of approximately 12 years.

Current TS 5.5.2 states, in part, that:

The next Unit 1 ILRT following the December 8, 2003 test shall be performed no later than March 8, 2015. The next Unit 2 ILRT following the May 29, 2004 test shall be performed no later than December 29, 2015. The next Unit 3 ILRT following the December 21, 2004 test shall be performed no later than July 21, 2016.

Revised TS 5.5.2 would be modified to state:

The next Unit 1 ILRT following the November 29, 2014 test shall be performed no later than November 29, 2026. The next Unit 2 ILRT following the November 7, 2015 test shall be performed no later than November 28, 2027. The next Unit 3 ILRT following the May 10, 2016 test shall be performed no later than May 25, 2028.

2.3 Regulatory Requirements and Guidance 2.3.1 Regulatory Requirements Title 10 of the Code of Federal Regulations (10 CFR) Part 50 provides the general provisions for Domestic Licensing of Production and Utilization Facilities. Under 10 CFR 50.90, whenever a holder of a license desires to amend the license, including technical specifications in the license, an application for amendment must be filed, fully describing the changes desired. 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 or construction permits to the extent applicable and appropriate. Both the common standards in 10 CFR 50.40(a), and those specifically for issuance of operating licenses in 10 CFR 50.57(a)(3),

provide that there must be reasonable assurance that the activities authorized can be conducted without endangering the health and safety of the public and will be in compliance with the regulations.

Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36, Technical specifications. Specifically, 10 CFR 50.36(c)(5), Administrative controls, state, in part, that:

Administrative controls are the provisions relating to organization and management, procedures, recordkeeping, review and audit, and reporting necessary to assure operation of the facility in a safe manner.

One of the conditions required of all operating licenses and combined licenses for light-water-cooled power reactors as specified in 10 CFR 50.54(o) is that primary reactor containments meet the leakage-rate test requirements in either Option A Prescriptive Requirements or Option B Performance-Based Requirements of Appendix J to 10 CFR Part 50. The testing requirements in Appendix J to 10 CFR Part 50 ensure that (a) leakage through containments or systems and components penetrating containments does not exceed allowable leakage rates specified in the TS, and (b) integrity of the containment structure is maintained during its service life. Option B of Appendix J identifies the performance-based requirements and criteria for preoperational and subsequent periodic leakage-rate testing.

Section V.B.3 of 10 CFR Part 50, Appendix J, Option B, states that the regulatory guide (RG) or other implementation document used by a licensee to develop a performance-based leakage-testing program must be included, by general reference, in the plant TSs.

The submittal for TS revisions must contain justification, including supporting analyses, if the licensee deviates from methods approved by the NRC which are endorsed in the RG.

Option B of Appendix J to 10 CFR Part 50, specifies performance-based requirements and criteria for preoperational and subsequent leakage rate testing. These requirements are met by performing (1) Type A tests to measure the containment system overall integrated leakage rate, (2) Type B pneumatic tests to detect and measure local leakage rates across pressure retaining leakage-limiting boundaries such as penetrations, and (3) Type C pneumatic tests to measure containment isolation valve leakage rates.

After the containment system has been completed and is ready for operation, Type A tests are conducted at periodic intervals based on the historical performance of the overall containment system to measure the overall integrated leakage rate. The leakage rate test results must not exceed the maximum allowable leakage (La) at design-basis loss-of-coolant accident (LOCA) pressure (Pa) with margin, as specified in the TS.

Option B also requires that a general visual inspection for structural deterioration of the accessible interior and exterior surfaces of the containment system be conducted prior to each Type A test and at a periodic interval between tests based on the performance of the containment system. A general visual inspection is necessary as structural deterioration of the surfaces of the containment system may affect the containments leak-tight integrity.

Type B and Type C tests are performed based on the safety significance and historical performance of each boundary and isolation valve to ensure integrity of the overall containment system as a barrier to fission product release.

The adoption of the Option B performance-based containment leakage rate testing for Types A, B, and C testing did not alter the basic method by which Appendix J to 10 CFR Part 50 leakage rate testing is performed; however, it did alter the frequency at which Types A, B, and C containment leakage tests may be performed. Under the performance-based option of 10 CFR Part 50, Appendix J, the test frequency is based upon an evaluation that reviewed as-found leakage history to determine the frequency for leakage testing which provides assurance that leakage limits will be maintained.

The regulation in 10 CFR 50.55a, Codes and standards, contain the containment inservice inspection (ISI) requirements, which, in conjunction with the requirements of 10 CFR Part 50, Appendix J, ensure the continued leak-tight and structural integrity of the containment during its service life.

2.3.2 Regulatory Guidance The TS for Oconee, as revised in the NRC issued licensed amendment dated October 30, 1996 (ML012050049), which approved the use of Option B for Type A tests, state in part: The containment leakage rate shall be determined, as required by 10 CFR 50.54(o) and 10 CFR50, Appendix J, Option B, including any approved exemptions, using the guidelines of Regulatory Guide 1.163, dated September, 1995.

RG 1.163, Revision 0, Performance-Based Containment Leak Test Program, (ML003740058),

endorses, with certain exceptions, NEI 94-01, Revision 0, as an acceptable method for complying with provisions of Appendix J. Section C.1 states that licensees intending to comply with 10 CFR 50, Appendix J, Option B, should establish test intervals based upon the criteria in Section 11.0 of NEI 94-01 rather than using test intervals specified in ANSI/ANS 56.8-1994.

Nuclear Energy Institute (NEI) 94-01, Revision 0, Industry Guideline for Implementing Performance-Based Option of 10 CFR Part 50, Appendix J, (ML11327A025), provides methods for complying with the provisions of 10 CFR Part 50, Appendix J, Option B, and includes provisions that address the extension of the performance-based Type A test interval for up to 10 years, based upon two consecutive successful tests.

NUREG-1493, Performance-Based Containment Leak-Test Program - Final Report September 1995, (ML20093H445) formed the basis of the allowed frequency for Type A testing in NEI 94-01. NUREG-1493, Section 10.1.2, Leakage-Testing Intervals, states, in part, that:

Reducing the frequency of Type A tests (ILRTs) from the current three per 10 years to one per 20 years was found to lead to an imperceptible increase in risk. The estimated increase in risk is very small because ILRTs identify only a few potential containment leakage paths that cannot be identified by Type B and C testing, and the leaks that have been found by Type A tests have been only marginally above existing requirements.

NUREG-1493, also states that:

Type B and C tests can identify the vast majority (greater than 95 percent) of all potential leakage paths.

Section 9.1 of NEI 94-01, Rev. 0, allows the recommended 10-year Type A test interval to be extended by up to an additional 15 months, but with the restriction that this option should be used only in cases where refueling schedules have been changed to accommodate other factors.

By letters dated October 1, 2012 (ML12250A339) and August 5, 2013 (ML13193A329) the NRC has approved one-time extensions of the Type A test frequency by 15 months for Oconee Nuclear Station Unit 1, and by 19 months for Oconee Nuclear Station Units 2 and 3, respectively.

3.0 TECHNICAL EVALUATION

3.1 Integrated Leak Rate Testing History (Type A Testing)

Per Oconee TS 5.5.2, the licensee specified a maximum allowable containment leakage rate, La, of 0.20 percent of the containment air weight per day at the calculated peak pressure, Pa.

TS 5.5.2 states that the peak calculated containment internal pressure for the design-basis LOCA, Pa, is 59 pounds per square inch gauge (psig). The containment design pressure is 59 psig as well.

The first ILRT tests were conducted for each of the unit on the following dates: Unit 1 on August 1971, Unit 2 on July 1973, and Unit 3 on May 1974. There have been 10 ILRTs performed on each of the Oconee containments, including the first. The licensee provided the results of these ILRTs, which show that substantial margin has been maintained relative to the performance criterion. The results of these ILRTs are documented in the license amendment request (LAR)

Section 3.2.3, Integrated Leak Rate Testing History.

Oconee TS 5.5.2 establishes the maximum limit for the as-left leakage rate for startup following completion of Type A testing at less than or equal to () 0.75 La, which currently equals 0.15 percent of containment air weight per day.

Oconee TS 5.5.2 specifies a leakage rate La not to exceed 0.20 percent of containment air weight per day at the calculated peak pressure, Pa. Prior to 2006, La was 0.25 percent of the containment air weight per day at Pa, which was less restrictive. As displayed in LAR section 3.2.3, Integrated Leak Rate Testing History, Table 3.2.3-2, ONS ILRT Results, the results of the most recent ILRTs are below the acceptance criteria with an upper 95 percent confidence limit.

The staff reviewed the past ILRT results provided by the licensee and found that Oconee has demonstrated adequate margin with respect to the TS leakage rate acceptance criteria.

Specifically, the most recent ILRTs resulted in less than 86 percent (i.e., > 14% margin) of the allowable as-left leakage (for Unit 1), less than 70 percent (i.e., > 30% margin) of the allowable as-left leakage (for Unit 2), and less than 73 percent (i.e., > 27% margin) of the allowable as-left leakage (for Unit 3). The NRC staff finds that there have been no ILRT failures nor any adverse trends in leakage.

Based on the above, the NRC staff finds that the ILRT performance of the Type A tests have demonstrated that the Oconee containments have a history of leak-tightness and structural integrity. Thus, the ILRT acceptance criteria would not be expected to be exceeded during the requested one-time 24-month extension.

The NRC staff concludes that the Oconee ILRT test results provide reasonable assurance that containment overall leakage will be maintained below the design-basis leak rate, consistent with the requirements in TS 5.5.2, and will fulfill the requirements of 10 CFR 50, Appendix J, Option B, during this one-time extended testing frequency period for each unit.

3.2 Type B and C Testing The leak-tight integrity of penetrations and isolation valves are verified through Type B and Type C local leak rate tests (LLRT). The overall leak-tight integrity and structural integrity of the primary containment is verified through a Type A test (ILRT) as required by 10 CFR 50, Appendix J. These tests are performed at the design-basis accident pressure. The testing frequency for Type B and Type C tests is not affected by the proposed amendment and will continue to be performed in accordance with NEI 94-01, Revision 0, as endorsed by RG 1.163.

The Oconee Appendix J, Type B and C leakage rate test program requires testing of electrical penetrations, airlocks, hatches, flanges, and containment isolation valves within the scope of the program, as required by 10 CFR 50, Appendix J, Option B, and TS 5.5.2. NRC staff notes that even though Oconee has adopted 10 CFR Part 50, Appendix J, Option B, Oconee has not implemented extended Type B or Type C LLRT intervals beyond the base interval of 30 months, as provided in NEI 94-01 Revision 0. Specifically, the component test intervals for Oconee components are on 24-month intervals, except airlocks, which are on 30-month intervals.

NRC staff reviewed the local leak rate summary provided in Section 3.3.5 of the LAR, Containment Leakage Rate Testing Program - Type B and Type C. For Oconee, the combined Type B and C leakage acceptance criterion is 0.60 La or 212,402 standard cubic centimeters per minute (sccm). Therefore, 1.0 La equals 354,000 sccm. The most recent local leak rate tests resulted in a total value of 22,238 sccm (for Unit 1), 19,372 sccm (for Unit 2), and 28,473 sccm (for Unit 3). The NRC staff notes that the Type B and C LLRT test results, since 2012, show a large margin between the total summation and the respective TS leakage rate acceptance criteria, which demonstrates the leak tightness of the Type B and C tested components. Specifically, since 2012, the average Type B and C leakage summation was 8.6 percent of 0.6La with a high of 13.7 percent of 0.6La (for Unit 1), 10.8 percent of 0.6La with a high of 18.5 percent of 0.6La (for Unit 2), and 15.6 percent of 0.6La with a high of 27.5 percent of 0.6La (for Unit 3).

As discussed in NUREG-1493, Performance-Based Leak-Test Program, Types B and C tests can identify the vast majority of all potential leakage paths in an ILRT. Therefore, the performance results of the Type B and C tests further provide a high degree of assurance that containment integrity will be maintained during the requested one-time 24-month extension period.

3.3 Containment Testing 3.3.1 Containment Inservice Inspection Programs The ISI Programs are summarized below for subsections IWE and IWL to the requirements of American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (ASME Code),Section XI, Inservice Inspection of Nuclear Power Plant Components, the 2007 Edition with the 2008 Addenda.

Service Level I Containment Coating and Assessment Program In Section 3.5.3, Coatings Program, of its submittal dated November 16, 2023, the licensee described the containment coatings program procedures which include: (1) establishment of coatings schedules, (2) selection and procurement of coatings, and (3) specifications for surface preparation and coating application requirements including inspection requirements and criteria.

The licensee stated that Oconee coatings program has been in effect since prior to initial licensing, is based on well-established industry standards, and has been revised as necessary on the bases of Oconee experience. The general results of the recent examinations of coatings were mostly minor damage limited to dings, scratches, and flaking topcoat. Based on review of the containment structural inspection results, the NRC staffs finds that the Oconee coatings program is effective in monitoring the condition of the coatings and making timely repairs as necessary to limit structural degradation to the containment liner.

Summary of ASME Section XI, Subsections IWE and IWL Containment ISI Programs The Containment ISI plan was developed to implement applicable requirements of 10 CFR 50.55a. The containment leak-tight integrity is verified through periodic ISIs conducted in accordance with the requirements of the ASME Code,Section XI, Subsection IWE and IWL, which provide the rules and requirements for the ISI of Class Metal Containment (MC) and Concrete Containment (CC) pressure-retaining components and their integral attachments.

ASME Section XI requires visual examinations three times within a 10-year interval for ASME Class MC components and their integral attachments (Subsection IWE) and two times within a 10-year interval for ASME Class CC components and their integral attachments (Subsection IWL). Furthermore, the methodology in NEI 94-01, Revision 0, requires that visual examinations be conducted during at least three other outages, in the outage during which the ILRT is being conducted, and that these requirements are not changed because of the extended ILRT interval.

In the Section 3.3.2, Containment Inservice Inspection (CISI) Program Scope, of its submittal dated November 16, 2023, the licensee outlined the requirements for the non-destructive examinations (NDEs) of Oconees containment pressure boundary and related components as specified by 10 CFR 50.55a. The licensee developed the CISI program in accordance with the requirements of ASME Section XI, Subsection IWE and IWL, 2007 Edition with 2008 Addenda and the applicable conditions in 10 CFR 50.55a(b)(2)(iii),Section XI condition: Concrete containment examinations, 10 CFR 50.55a(b)(2)(ix),Section XI condition: Metal containment examinations, and any approved relief requests approved by the NRC. Table 3.3.2-7 Category L-A: Concrete, through Table 3.3.2-11 Affected by Repair and Replacement Activity, provide the general examination criteria to fulfill the applicable ASME Section XI, Subsection IWL requirements. Table 3.3.2-12Category E-C: Containment Surfaces Requiring Augmented Examination, and Table 3.3.2-13 Category E-G: Pressure Retaining Bolting, provide the general examination criteria to fulfill the applicable ASME Section XI, Subsection IWE requirements.

The licensee provided the dates of inspection periods for the containment pressure boundary inspection intervals with modifications in accordance with the approved Request for Alternative Serial #03-GO-10, and is as follows:

The CISI periods during the third 10-year containment inspection interval for Unit 1:

First Period (36 months):

July 15, 2014, to July 14, 2017 Second Period (36 months): July 15, 2017, to July 14, 2020 Third Period (36 months):

July 15, 2020, to July 15, 2024 And with IWL examinations scheduled on the following dates:

45th year exams: August 4, 2015, to August 4, 2017 50th year exams: August 4, 2020, to August 4, 2022 The CISI periods during the third 10-year containment inspection interval for Unit 2:

First Period (36 months):

July 15, 2014, to July 14, 2018 Second Period (36 months): July 15, 2018, to July 14, 2021 Third Period (36 months):

July 15, 2021, to July 15, 2024 And with IWL examinations scheduled on the following dates:

45th year exams: June 22, 2017, to June 22, 2019 50th year exams: June 22, 2022, to June 22, 2024 The CISI periods during the third 10-year containment inspection interval for Unit 3:

First Period (36 months):

July 15, 2014, to July 14, 2018 Second Period (36 months): July 15, 2018, to July 14, 2021 Third Period (36 months):

July 15, 2021, to July 15, 2024 And with IWL examinations scheduled on the following dates:

45th year exams: May 7, 2018, to May 7, 2020 50th year exams: May 7, 2023, to May 7, 2025 The proposed CISI periods during the fourth 10-year containment inspection interval for Unit 1:

First Period (36 months):

July 15, 2024, to July 14, 2027 Second Period (36 months): July 15, 2027, to July 14, 2030 Third Period (36 months):

July 15, 2030, to July 15, 2034 And with IWL examinations scheduled on the following dates:

55th year exams: August 4, 2025, to August 4, 2027 60th year exams: August 4, 2030, to August 4, 2032 The proposed CISI periods during the fourth 10-year containment inspection interval for Unit 2:

First Period (36 months):

July 15, 2024, to July 14, 2028 Second Period (36 months): July 15, 2028, to July 14, 2031 Third Period (36 months):

July 15, 2031, to July 15, 2034 And with IWL examinations scheduled on the following dates:

55th year exams: June 22, 2027, to June 22, 2029 60th year exams: June 22, 2032, to June 22, 2034 The proposed CISI periods during the fourth 10-year containment inspection interval for Unit 3:

First Period (36 months):

July 15, 2024, to July 14, 2028 Second Period (36 months): July 15, 2028, to July 14, 2031 Third Period (36 months):

July 15, 2031, to July 15, 2034 And with IWL examinations scheduled on the following dates:

55th year exams: May 7, 2028, to May 7, 2030 60th year exams: May 7, 2033, to May 7, 2035 Additionally, the licensee referenced ASME Section XI, IWA-2430, which allows the inspection intervals to be increased or decreased by 12 months, if necessary.

Summary of the Containment Inservice Inspection Examination Results:

In Section 3.3.3 Results of Recent Containment Examinations, of its submittal dated November 16, 2023, the licensee stated:

The results of recent visual examinations of IWE surfaces are detailed in Tables 3.3.3-1 through 3.3.3-7 below. Note that the contents of Tables 3.3.3-1 through 3.3.3-7 do not include the results of inspections where there were "No Reportable Indications", and the inspection results were evaluated and found acceptable.

The results of recent visual examinations of IWL surfaces are detailed in Table 3.3.3-8 through 3.3.3-11 below. Note that the contents of Table 3.3.3-8 through 3.3.3-11 do not include the results of inspections where there were No Reportable Indications, and the inspection results were evaluated and found acceptable.

The NRC staff reviewed Tables 3.3.3-1 through 3.3.3-11 and found that the reported conditions were minor where Oconee accepted the results, or Oconee had already repaired or issued work orders for the repairs for the more advanced abnormal conditions. The NRC staff noted that the accepted abnormal conditions are minor in nature and do not impact the function of the containment pressure boundary system.

The NRC staff noted that Enclosure to the LAR Section 3.3.3 Results of Recent Containment Examinations, Part Oconee Unit 2 2019 Moisture Barrier Inspection, identified nine non-conforming conditions during the examination of the moisture barrier without resolutions. A degraded moisture barrier could indicate the presence of degradation in the inaccessible areas behind the moisture barrier. Furthermore, a degraded moisture barrier could allow moisture to contact the containment and cause degradation in an inaccessible area. The NRC staff requested the licensee to (1) summarize the results of any 10 CFR 50.55a(b)(2)(ix)(A) evaluations associated with the non-conforming moisture barrier conditions, and (2) describe the corrective actions taken or engineering evaluation for the non-conforming moisture barrier conditions.

In its response dated April 19, 2024, the licensee stated, in part, that:

1. Per IWE-3512, degraded moisture barriers that could permit intrusion of moisture against inaccessible surfaces of the metallic containment liner shall be corrected by corrective measures. Therefore, all identified areas with degradation or delamination were replaced with new moisture barriers and reinspected in accordance with ASME Section XI, Section IWE-3122.2 during O2R29 [Fall, 2019]. When the old moisture barrier was removed, the liner behind the moisture barrier was made accessible for VT-1 examination. A VT-1 examination of the exposed metallic containment liner was performed and revealed no corrosion or relevant conditions. Therefore, since all the metallic containment liner located behind degraded moisture barriers was examined and no relevant conditions were identified, evaluations associated with inaccessible portions of the containment were not required.

2. Prior to completing outage O2R29, corrective measures in compliance with IWE-3122.2 were performed on all degraded moisture barriers identified during the IWE visual examinations. Specifically, all degraded/delaminated moisture barriers identified were completely removed allowing accessibility to perform a VT-1 exam of the exposed metallic containment liner. These VT-1 examinations revealed no corrosion or relevant conditions associated with the metallic containment liner. As needed, touch-up coatings were applied to the containment liner in accordance with site coatings maintenance requirements. Following these metallic liner coating repairs, a new moisture barrier was installed between the liner and the concrete basement floor.

Based on the above, the NRC staff finds that the licensee has an adequate containment ISI program in place as demonstrated by the implementation of overlapping inspection activities performed as part of the IWE/IWL programs. These programs periodically examine, monitor, and manage structural deterioration and aging degradation of the containment pressure boundary such that the primary containment can perform its intended function as a leak-tight barrier consistent with the requirements of ASME Section XI, Subsection IWE and IWL, and the applicable conditions in 10 CFR 50.55a(b)(2).

In Section 3.1.2, Containment Isolation System, of its submittal dated November 16, 2023, the licensee described the types of fluid penetrations which require isolation after an accident. In the subsection entitled, Periodic Operability Tests, the licensee stated that each containment isolation valve will be tested periodically during normal operation or during shutdown conditions to assure its operability when needed. In addition, the licensee stated that a program of testing and surveillance of each of the three Reactor Buildings has been developed to provide assurance, during service, of the capability of each containment system to perform its intended safety function. The NRC regulations require the licensee to implement the ASME OM Code as incorporated by reference in 10 CFR 50.55a for the IST Program to assess the operational readiness of specific pumps, valves, and dynamic restraints.

In a request for additional information (RAI), the NRC staff requested the licensee to describe any changes to the Inservice Testing (IST) Program, including testing of containment isolation valves, that will be implemented as part of the proposed change. In its supplement dated April 19, 2024, the licensee stated that no changes to the IST Program at ONS will be implemented as a result of this proposed change to revise TS 5.5.2 for a one-time extension of the containment Type A leak rate test frequency. Based on this response, the NRC staff has not identified any concerns with the impact on the IST Program from the proposed change to revise TS 5.5.2 at ONS.

3.3.2 Operating Experience In Section 3.4, Operating Experience, of its submittal dated November 16, 2023, the licensee described the impacts of the following selected site-specific and industry operating experiences.

In Section 3.4.1, IN 1992-20, Inadequate Local Leak Rate Testing, of its submittal dated November 16, 2023, the licensee reviewed for applicability to Oconee, NRC Information Notice (IN) 92-20, Inadequate Local Leak Rate Testing, dated March 3, 1992 (ML031200473). The NRC issued IN 92-20 to alert licensees to problems with the local leak rate testing of two-ply stainless-steel bellows used on piping penetrations at some plants. The licensee stated that, At ONS [Oconee], the only bellows assemblies present on each unit is found on the fuel transfer tube penetrations. However, the transfer tube penetrations are welded directly to the containment liner and the bellows do not represent a containment atmospheric release pathway.

ONS does not have the problems described in IN 92-20.

In Section 3.4.2, IN 2010-12, Containment Liner Corrosion, of its submittal dated November 16, 2023, the licensee reviewed for applicability to Oconee containment, steel liner-plate NRC IN 2010-12, Containment Liner Corrosion, dated June 18, 2010 (ML100640449). The NRC issued IN 2010-12 to inform licensees of issues concerning the degradation (corrosion) of the containment liner that could affect the leak-tightness of the carbon steel liner. The licensee stated, in part, that, Operating experience shows that containment liner corrosion is often the result of liner plates being in contact with objects and materials that are lodged between or embedded in the containment concrete However, corrosion that originates between the liner plate and concrete is of a greater concern because visual examinations typically identify the corrosion only after it has significantly degraded the liner. In some cases, licensees identified such corroded areas by performing ultrasonic examination of suspect areas (e.g., areas of obvious bulging, hollow sound). 10 CFR 50.55a require the use of ASME Section XI, Subsection IWE to perform in-service inspections of containment components, such as the steel containment liner and attachments, using visual examinations and ultrasonic thickness measurements. The licensee noted that, at Oconee, the Containment IWE Program and examination procedures contain steps to perform visual examinations for corrosion of the steel liner and identify liner bulge areas.

In Section 3.4.3, RIS 2016-07, Containment Shell or Liner Moisture Barrier Inspection, of its submittal dated November 16, 2023, the licensee reviewed for applicability to Oconee, containment moisture barrier inspection NRC Regulatory Issue Summary (RIS) 2016-07, Containment Shell or Liner Moisture Barrier Inspection, dated May 9, 2016 (ML16068A436).

The NRC issued RIS 2016-07 to all licensees to reiterate the NRCs position regarding in-service inspection requirements for moisture barrier materials. In accordance with ASME Section XI, Table IWE-2500-1, Item E1.30, the NRC expects licensees to inspect 100 percent of accessible moisture barriers during each inspection period. The licensee stated that RIS 2016-07 is applicable to ONS and has taken the following actions during outages 1EOC29, 2EOC28, and 3EOC29:

1. Identify all specific locations within each containment where the following conditions exist: (1) back-to-back metal interfaces at the containment shell or liner, (2) interface between the containment shell or liner and adjacent concrete, and (3) expansion joints and other concrete-to-concrete interfaces.

For each of these, identify and document whether any moisture barrier material exists and the configuration and type of moisture barrier present including any coatings that seal the interface.

2. If the moisture barrier at the identified locations is missing or has degraded such that water intrusion could occur, (1) install a moisture barrier and revise the Inservice Inspection Plan to document the location, or (2) document the basis for why the inaccessible surfaces of the containment shell or liner are not subjected to augmented examination in accordance with IWE-1241, or (3) revise the ISI plan to document and included the interface for augmented examination.

3. Verify that procedures for performing Table IWE-2500-1, Examination Category E-A, Item E1.30 examinations contain sufficient information pertaining to the scope and acceptance standards for visual examination of all types of moisture barriers at each site.

The NRC staff reviewed Table 3.3.2-12, Category E-A: Containment Surfaces, in Section 3.3.2, Containment Inservice Inspection (CISI) Program Scope, of its submittal dated November 16, 2023, and noted the licensee is committed to inspecting 100% of moisture barriers during every inspection period within each interval.

3.4 NRC Staff Conclusion

Based on the preceding regulatory and technical evaluations, the NRC staff finds that the licensee has sufficiently implemented its existing primary containment leakage rate testing program consisting of ILRTs and LLRTs. The results of the recent ILRTs and LLRTs combined totals demonstrate acceptable performance and support a conclusion that the structural and leak-tight integrity of the primary containment is being managed sufficiently and will continue to be monitored and managed effectively with the proposed changes. Therefore, the NRC staff concludes that the proposed changes to Oconee TS 5.5.2 regarding the containment leakage rate testing program are acceptable.

This is a one-time NRC approval. Future Type A tests must be conducted within the due dates for each interval established in revised TS 5.5.2 unless NRC approval is obtained for future extensions.

3.5 Evaluation of TS Changes The licensee proposed to change Oconee TS 5.5.2 as described in Section 2.2 of this safety evaluation. Based on the above, the NRC staff concludes that the proposed changes to Oconee TS 5.5.2 to provide a one-time extension to the Oconee ILRT test interval from its current 10-year frequency to a maximum of approximately 12 years is acceptable because the proposed change would continue to provide reasonable assurance of operation of the facility in a safe manner. Therefore, the NRC staff finds that the Oconee TS 5.5.2 proposed change will continue to meet 10 CFR 50.36(c)(5) and 10 CFR 50, Appendix J, and is, therefore, acceptable.

4.0 STATE CONSULTATION

In accordance with the Commission's regulations, the South Carolina State official was notified of the proposed issuance of the amendments on June 20, 2024. On August 26, 2024, the State official confirmed that the State of South Carolina had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

The amendments change the requirements with respect to the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20. 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 Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration published in the Federal Register on January 23, 2024 (89 FR 4342), 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 Commission's 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 Contributors:

T. Scarbrough, NRR S. Lai, NRR M. Yoder, NRR R. Boruk, NRR B. Lee, NRR R. Atienza, NRR J. Wilson, NRR Date: August 26, 2024