ML20253A321
| ML20253A321 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 01/26/2021 |
| From: | Andrew Hon Plant Licensing Branch II |
| To: | Krakuszeski J Duke Energy Progress |
| Hon A | |
| References | |
| EPID L-2020-LLA-0168 | |
| Download: ML20253A321 (20) | |
Text
January 26, 2021 Mr. John A. Krakuszeski Vice President Brunswick Steam Electric Plant Duke Energy Progress, LLC 8470 River Rd. SE (M/C BNP001)
Southport, NC 28461
SUBJECT:
BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 - ISSUANCE OF AMENDMENT NOS. 302 AND 330 RE: REVISE TECHNICAL SPECIFICATION 3.6.3.1 TO ADOPT TSTF-568, REVISION 2, REVISE APPLICABILITY OF BWR/4 TS 3.6.2.5 AND TS 3.6.3.2 (EPID L-2020-LLA-0168)
Dear Mr. Krakuszeski:
The U.S. Nuclear Regulatory Commission (the Commission) has issued the enclosed Amendment Nos. 302 and 330 to Renewed Facility Operating License Nos. DPR-71 and DPR-62 for Brunswick Steam Electric Plant, Units 1 and 2. The amendments consist of changes to the technical specifications (TSs) in response to your application dated July 27, 2020.
The amendments adopt Technical Specifications Task Force (TSTF) Traveler TSTF-568, Revision 2, Revise Applicability of BWR [Boiling Water Reactor]/4 TS 3.6.2.5 and TS 3.6.3.2, using the Consolidated Line Item Improvement Process. The amendments also revise TS 3.6.3.1, Primary Containment Oxygen Concentration, and present the requirements in a manner more consistent with the standard TSs format and content.
A copy of the related Safety Evaluation is also enclosed. Notice of Issuance will be included in the Commissions monthly Federal Register Notice.
Sincerely,
/RA/
Andrew Hon, Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-325 and 50-324
Enclosures:
- 1. Amendment No. 302 to License No. DPR-71
- 2. Amendment No. 330 to License No. DPR-62
- 3. Safety Evaluation cc: Listserv
DUKE ENERGY PROGRESS, LLC DOCKET NO. 50-325 BRUNSWICK STEAM ELECTRIC PLANT, UNIT 1 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 302 Renewed License No. DPR-71
- 1.
The U.S. Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment filed by Duke Energy Progress, LLC (the licensee), dated July 27, 2020, 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 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.
- 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-71 is hereby amended to read as follows:
(2)
Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 302, are hereby incorporated in the license. Duke Energy Progress, LLC shall operate the facility in accordance with the Technical Specifications.
- 3.
This license amendment is effective as of the date of its issuance and shall be implemented in 120 days.
FOR THE NUCLEAR REGULATORY COMMISSION Undine S. Shoop, Chief Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Attachments:
Changes to the Renewed Facility Operating License and Technical Specifications Date of Issuance: January 26, 2021 Undine S.
Shoop Digitally signed by Undine S. Shoop Date: 2021.01.26 14:35:42 -05'00'
ATTACHMENT TO LICENSE AMENDMENT NO. 302 BRUNSWICK STEAM ELECTRIC PLANT, UNIT 1 RENEWED FACILITY OPERATING LICENSE NO. DPR-71 DOCKET NO. 50-325 Replace page 6 of Renewed Facility Operating License No. DPR-71 with the attached page 6.
Replace the following page of the Appendix A Technical Specifications with the attached revised page. The revised page is identified by amendment number and contains a marginal line indicating the area of change.
Remove Page Insert Page 3.6-26 3.6-26
6 Renewed License No. DPR-71 Amendment No. 302 (c)
Transition License Conditions
- 1. Before achieving full compliance with 10 CFR 50.48(c), as specified by 2. below, risk-informed changes to the licensees fire protection program may not be made without prior NRC review and approval unless the change has been demonstrated to have no more than a minimal risk impact, as described in 2. above.
- 2. The licensee shall implement the modifications to its facility, as described in Table S-1, Plant Modifications Committed, of Duke letter BSEP 14-0122, dated November 20, 2014, to complete the transition to full compliance with 10 CFR 50.48(c) by the startup of the second refueling outage for each unit after issuance of the safety evaluation. The licensee shall maintain appropriate compensatory measures in place until completion of these modifications.
- 3. The licensee shall complete all implementation items, except item 9, listed in LAR Attachment S, Table S-2, Implementation Items, of Duke letter BSEP 14-0122, dated November 20, 2014, within 180 days after NRC approval unless the 180th day falls within an outage window; then, in that case, completion of the implementation items, except item 9, shall occur no later than 60 days after startup from that particular outage. The licensee shall complete implementation of LAR Attachment S, Table S-2, Item 9, within 180 days after the startup of the second refueling outage for each unit after issuance of the safety evaluation.
C.
This renewed 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; and is subject to all applicable provisions 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 2923 megawatts thermal.
(2)
Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 302, are hereby incorporated in the license. Duke Energy Progress, LLC shall operate the facility in accordance with the Technical Specifications.
For Surveillance Requirements (SRs) that are new in Amendment 203 to Renewed Facility Operating License DPR-71, the first performance is due at the end of the first surveillance interval that begins at implementation of Amendment 203. For SRs that existed prior to Amendment 203, including SRs with modified acceptance criteria and SRs whose frequency of
Primary Containment Oxygen Concentration 3.6.3.1 Brunswick Unit 1 3.6-26 Amendment No. 302276 3.6 CONTAINMENT SYSTEMS 3.6.3.1 Primary Containment Oxygen Concentration LCO 3.6.3.1 The primary containment oxygen concentration shall be < 4.0 volume percent.
APPLICABILITY:
MODES 1 and 2.
ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.
Primary containment oxygen concentration not within limit.
A.1
NOTE--------------
LCO 3.0.4.c is applicable.
Restore oxygen concentration to within limit.
72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> B.
Required Action and associated Completion Time not met.
B.1 Be in MODE 3.
12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.3.1.1 Verify primary containment oxygen concentration is within limits.
In accordance with the Surveillance Frequency Control Program
DUKE ENERGY PROGRESS, LLC DOCKET NO. 50-324 BRUNSWICK STEAM ELECTRIC PLANT, UNIT 2 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 330 Renewed License No. DPR-62
- 1.
The U.S. Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment filed by Duke Energy Progress, LLC (the licensee), dated July 27, 2020, 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 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.
- 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-62 is hereby amended to read as follows:
(2)
Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 330, are hereby incorporated in the license. Duke Energy Progress, LLC shall operate the facility in accordance with the Technical Specifications.
- 3.
This license amendment is effective as of the date of its issuance and shall be implemented in 120 days.
FOR THE NUCLEAR REGULATORY COMMISSION Undine S. Shoop, Chief Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Attachments:
Changes to the Renewed Facility Operating License and Technical Specifications Date of Issuance: January 26, 2021 Undine S.
Shoop Digitally signed by Undine S. Shoop Date: 2021.01.26 14:36:34 -05'00'
ATTACHMENT TO LICENSE AMENDMENT NO. 330 BRUNSWICK STEAM ELECTRIC PLANT, UNIT 2 FACILITY OPERATING LICENSE NO. DPR-62 DOCKET NO. 50-324 Replace page 6 of Renewed Facility Operating License No. DPR-62 with the attached page 6.
Replace the following page of the Appendix A Technical Specifications with the attached revised page. The revised page is identified by amendment number and contains a marginal line indicating the area of change.
Remove Page Insert Page 3.6-26 3.6-26
6 Renewed License No. DPR-62 Amendment No. 330 (c)
Transition License Conditions
- 1. Before achieving full compliance with 10 CFR 50.48(c), as specified by 2. below, risk-informed changes to the licensees fire protection program may not be made without prior NRC review and approval unless the change has been demonstrated to have no more than a minimal risk impact, as described in 2. above.
- 2. The licensee shall implement the modifications to its facility, as described in Table S-1, Plant Modifications Committed, of Duke letter BSEP 14-0122, dated November 20, 2014, to complete the transition to full compliance with 10 CFR 50.48(c) by the startup of the second refueling outage for each unit after issuance of the safety evaluation. The licensee shall maintain appropriate compensatory measures in place until completion of these modifications.
- 3. The licensee shall complete all implementation items, except Item 9, listed in LAR Attachment S, Table S-2, Implementation Items, of Duke letter BSEP 14-0122, dated November 20, 2014, within 180 days after NRC approval unless the 180th day falls within an outage window; then, in that case, completion of the implementation items, except item 9, shall occur no later than 60 days after startup from that particular outage. The licensee shall complete implementation of LAR Attachment S, Table S-2, Item 9, within 180 days after the startup of the second refueling outage for each unit after issuance of the safety evaluation.
C.
This renewed 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 2923 megawatts (thermal).
(2)
Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 330, are hereby incorporated in the license. Duke Energy Progress, LLC shall operate the facility in accordance with the Technical Specifications.
For Surveillance Requirements (SRs) that are new in Amendment 233 to Renewed Facility Operating License DPR-62, the first performance is due at the end of the first surveillance interval that begins at implementation of Amendment 233. For SRs that existed prior to Amendment 233,
Primary Containment Oxygen Concentration 3.6.3.1 Brunswick Unit 2 3.6-26 Amendment No. 3300 3.6 CONTAINMENT SYSTEMS 3.6.3.1 Primary Containment Oxygen Concentration LCO 3.6.3.1 The primary containment oxygen concentration shall be < 4.0 volume percent.
APPLICABILITY:
MODES 1 and 2.
ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.
Primary containment oxygen concentration not within limit.
A.1
NOTE--------------
LCO 3.0.4.c is applicable.
Restore oxygen concentration to within limit.
72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> B.
Required Action and associated Completion Time not met.
B.1 Be in MODE 3.
12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.3.1.1 Verify primary containment oxygen concentration is within limits.
In accordance with the Surveillance Frequency Control Program
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 302 AND 330 TO RENEWED FACILITY OPERATING LICENSES NOS. DPR-71 AND DPR-62 DUKE ENERGY PROGRESS, LLC BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 DOCKET NOS. 50-325 AND 50-324
1.0 INTRODUCTION
By application dated July 27, 2020 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML20209A551), Duke Energy Progress, LLC (the licensee) submitted a license amendment request (LAR) for Brunswick Steam Electric Plant (Brunswick), Units 1 and 2.
The proposed changes would revise Technical Specification (TS) 3.6.3.1, Primary Containment Oxygen Concentration. The proposed changes would simplify and clarify the applicability statements, which, if misapplied, could conflict with the corresponding required actions. The proposed changes would also remove the undefined term scheduled plant shutdown and provide adequate terminal actions.
The proposed amendments are based on Technical Specifications Task Force (TSTF) Traveler TSTF-568, Revision 2, Revise Applicability of BWR [Boiling Water Reactor]/4 TS 3.6.2.5 and TS 3.6.3.2 (TSTF-568, Revision 2, or the traveler) (ADAMS Accession No. ML19141A122).
The U.S. Nuclear Regulatory Commission (NRC, the Commission) approved TSTF-568, Revision 2, by letter dated December 17, 2019 (ADAMS Package Accession No. ML19325C444). The NRC staffs safety evaluation (SE) of the traveler was enclosed with the NRC staffs approval letter.
The licensee has proposed variations from the TS changes described in TSTF-568, Revision 2.
The variations are described in Section 2.2.2 and evaluated in Section 3.0 of this SE.
The proposed change to the standard technical specification (STS) STS 3.6.2.5, Drywell-to-Suppression Chamber Differential Pressure, in TSTF-568 is not applicable to Brunswick, Units 1 and 2; therefore, the licensee did not include it in its LAR.
2.0 REGULATORY EVALUATION
2.1 Description of Structures, Systems, Components, and Technical Specification Sections 2.1.1 Current Containment Oxygen Concentration Requirement Title 10 of the Code of Federal Regulations (10 CFR) Section 50.44, Combustible gas control for nuclear power reactors, states that for a plant with an inerted containment atmosphere, the oxygen concentration in the primary containment is required to be maintained below 4 percent by volume during normal plant operation. This requirement ensures that an accident that produces hydrogen does not result in a combustible mixture inside the primary containment.
The current TS 3.6.3.1 requires primary containment oxygen concentration to be less than 4 percent by volume when in Mode 1 during the period from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the thermal power exceeds 15 percent reactor thermal power (RTP) following startup and to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to reducing the RTP to less than 15 percent RTP during the next scheduled shutdown. TSTF-568, Revision 2, states that the 24-hour allowance above 15 percent RTP is provided in the primary containment oxygen concentration specification to delay inerting the primary containment in a plant startup and to accelerate de-inerting for a plant shutdown. This allowance is provided so that plant personnel can safely enter the primary containment without breathing apparatus to perform the needed inspections and maintenance adjustments.
The containment consists of a drywell (in the shape of an inverted lightbulb), a suppression chamber (in the shape of a toroid), and a network of vents that extend radially outward and downward from the drywell to the suppression chamber. The containment atmosphere is inerted with nitrogen gas during normal operation to prevent a combustible mixture of hydrogen and oxygen from forming during accident conditions. Long-term control of post-loss-of-coolant accident (LOCA) hydrogen gas concentration is accomplished by adding additional nitrogen gas and then venting the primary containment through the standby gas treatment system.
2.1.2 Pressure Suppression Following a Loss-of-Coolant Accident The drywell is immediately pressurized when a postulated line break occurs within the primary containment. As drywell pressure increases, drywell atmosphere (primarily nitrogen gas) and steam are blown down through the vents into the suppression pool via the downcomers. The steam condenses in the suppression pool, which suppresses the peak pressure in the drywell.
Non-condensable gases discharged into the suppression pool collect in the free air volume of the suppression chamber, increasing the suppression chamber pressure. As steam is condensed in the suppression pool and on the structures in the drywell, the pressure decreases until the suppression chamber pressure exceeds the drywell pressure and the suppression chamber-drywell vacuum breakers open and vent non-condensable gases back into the drywell.
2.1.3 TS 3.6.3.1, Primary Containment Oxygen Concentration The primary containment oxygen concentration is maintained to ensure that a LOCA, a postulated event that produces hydrogen, does not result in a combustible mixture inside primary containment. The TS requires that the primary containment oxygen concentration be maintained below 4 percent by volume. Below this concentration, the primary containment is inerted and no combustion can occur.
2.2 Description of Proposed Technical Specification Changes 2.2.1 Proposed Changes to TS 3.6.3.1, Primary Containment Oxygen Concentration The applicability of TS 3.6.3.1 would be revised as shown below:
Current TS Applicability Proposed TS Applicability MODE 1 during the time period:
- a. From 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after THERMAL POWER is > 15% RTP following startup, to
- b. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to a scheduled reduction of THERMAL POWER to < 15% RTP.
MODES 1 and 2.
Required Actions A.1 and B.1 and their associated completion times would be revised as shown below:
The NRC staff understands the overall purpose of the proposed changes is to simplify the applicability statement by adding a new note and revising the completion time. This change provides operational flexibility but more closely follows established TS conventions and requires that the plant be in Mode 3 if oxygen concentration cannot be restored to within limits.
2.2.2 Variations The proposed change to STS 3.6.2.5, Drywell-to-Suppression Chamber Differential Pressure, in TSTF-568 is not applicable to Brunswick and is not included.
The Brunswick TSs for Units 1 and 2 use different numbering than the standard technical specifications (STSs) on which TSTF-568 was based. Specifically, STS 3.6.3.2, Primary Containment Oxygen Concentration, is Brunswick TS 3.6.3.1, Primary Containment Oxygen Concentration. This difference does not affect the applicability of TSTF-568 to the Brunswick TSs.
2.3 Applicable Regulatory Requirements and Guidance Section 50.90 of 10 CFR, Application for amendment of license, construction permit, or early site permit, requires that whenever a licensee 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.
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 for licenses and construction permits 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 at issue will not endanger the health and safety of the public.
Section 50.36 of 10 CFR, Technical specifications, establishes the regulatory requirements related to the content of TSs. Section 50.36(a)(1) of 10 CFR requires an application for an operating license to include proposed TSs. A summary statement of the bases or reasons for such specifications, other than those covering administrative controls, must also be included in the application, but shall not become part of the TSs.
The regulation 10 CFR 50.36(b) requires:
Each license authorizing operation of a utilization facility will include technical specifications. The technical specifications will be derived from the analyses and evaluation included in the safety analysis report, and amendments thereto, submitted pursuant to [10 CFR] 50.34 [Contents of applications; technical information]. The Commission may include such additional technical specifications as the Commission finds appropriate.
The categories of items required to be in the TSs are listed in 10 CFR 50.36(c).
In accordance with 10 CFR 50.36(c)(2), limiting conditions for operation (LCOs) are the lowest functional capability or performance levels of equipment required for safe operation of the facility. When LCOs are not met, the licensee must shut down the reactor or follow any remedial action permitted by the TSs until the condition can be met. In addition, 10 CFR 50.36(c)(2)(ii)(B) requires a TS LCO of a nuclear reactor must be established for a process variable, design feature, or operating restriction that is an initial condition of a design-basis accident or transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.
The regulation in 10 CFR 50.44(b)(2)(i) states, All boiling water reactors with Mark I or Mark II type containments must have an inerted atmosphere. Section 50.44(a)(1) of 10 CFR defines inerted atmosphere as a containment atmosphere with less than 4 percent of oxygen by volume.
NUREG-0800, Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR [Light Water Reactor] Edition (SRP), Chapter 6.2.1.1.C, Revision 7, Pressure-Suppression Type BWR Containments, dated March 2007 (ADAMS Accession No. ML063600403), states: The acceptability of pool dynamic loads for plants with Mark I containments is based on conformance with NRC acceptance criteria found in NUREG-06611.
The NRC staffs guidance for the review of TSs is in Section 16.0, Revision 3, Technical Specifications, of the SRP, dated March 2010 (ADAMS Accession No. ML100351425). As described therein, as part of the regulatory standardization effort, the NRC staff has prepared STS for each of the light water reactor nuclear designs. Accordingly, the NRC staffs review includes consideration of whether the proposed changes are consistent with the applicable reference STS (i.e., the current STS), as modified by NRC-approved travelers. The STS applicable to Brunswick is NUREG-1433, Revision 4.0, Standard Technical Specifications, General Electric BWR/4 Plant, Volume 1, Specifications, and Volume 2, Bases, dated April 2012 (ADAMS Accession Nos. ML12104A192 and ML12104A193, respectively).
3.0 TECHNICAL EVALUATION
The proposed amendments are based on NRC-approved TSTF-568, Revision 2. The NRC staff also considered the regulations and guidance discussed in Section 2.3 of this SE in its review.
3.1 Proposed Changes to TS 3.6.3.1 3.1.1 Proposed Changes in the Applicability In accordance with NRC-approved TSTF-568, Revision 2, the licensee proposed to expand the applicability of this LCO to Modes 1 and 2 without exception. The NRC staff finds the proposed change acceptable because it is more restrictive since an unlikely LOCA event leading to a degraded core that could produce hydrogen has the highest probability of occurrence during Modes 1 and 2 conditions.
3.1.2 Proposed Changes in Required Action A.1 In accordance with NRC-approved TSTF-568, Revision 2, the licensee proposed to add the following note to Required Action A.1: LCO 3.0.4.c is applicable. TS LCO 3.0.4.c allows entering the mode of applicability of TS LCO 3.6.3.1 with the LCO not met. Therefore, the proposed change would permit entry into Modes 1 and 2 with primary containment oxygen concentration higher than the required limit. The NRC staff concludes the addition of the note is acceptable because it clarifies and simplifies the intent of the current TS LCO 3.6.3.1 applicability statement a. of allowing startup operation with the LCO not met.
3.1.3 Proposed Changes in the Completion Time of Condition A In accordance with NRC-approved TSTF-568, Revision 2, the licensee proposed changing the completion time from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> based on the following sequence of operations:
allow 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to de-inert the containment to permit safe personnel access, allow 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to perform the required maintenance or repair work, and allow 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to inert the containment.
The NRC staff determined that the presence of a higher oxygen concentration for the 72-hour 1 U.S. Nuclear Regulatory Commission, NUREG-0661, "Safety Evaluation Report, Mark I Containment Long-Term Program, Resolution of Generic Technical Activity A-7," dated July 1980 (ADAMS Accession No. ML072710452).
completion time is appropriate, considering the low safety significance of the change for potential accidents and the additional restrictions and conservatisms in the revised applicability.
3.1.4 Proposed Changes in Required Action B.1 In accordance with NRC-approved TSTF-568, Revision 2, the licensee proposed to change the applicability statement of TS LCO 3.6.3.1 to Modes 1 and 2. If the oxygen concentration cannot be restored within the required limit and completion time of Required Action A.1, the reactor must be brought to Mode 3. In this mode, the reactor would be in a hot shutdown condition (control rods fully inserted) with all reactor vessel head bolts fully tensioned.
The NRC staff recognizes that on entering Mode 3, the decay heat is rapidly decreasing. Steam is initially available for operating the reactor core isolation cooling/high-pressure coolant injection steam turbine-driven pumps until the reactor pressure, and thus, water temperature, is substantially reduced. As the decay heat continues to decrease, operators have increased time and options for achieving adequate water injection using the low-pressure emergency core cooling system to avoid core damage and associated generation of combustible gas.
Therefore, the occurrence of a LOCA leading to degraded core is highly unlikely in Mode 3.
The NRC staff finds the proposed change in Required Action B.1 acceptable because it provides a more appropriate terminal action since it requires the plant to be placed in a mode in which the LCO does not apply and the oxygen concentration limit is no longer required. The previous terminal action allowed an indefinite period of operation at 15 percent RTP.
Due to the low potential for hydrogen generation when the reactor is in Mode 3, inerting of containment in Mode 3 is not needed. Therefore, the NRC staff concluded the proposed change is acceptable because it continues to protect containment integrity and meets 10 CFR 50.36(c)(2) by providing the lowest functional capability of equipment required for safe operation of the plant.
3.1.5 Proposed Changes in the Completion Time of Condition B In accordance with NRC-approved TSTF-568, Revision 2, the licensee proposed to change the Condition B completion time from 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, stating that 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is a reasonable time to reduce reactor power from full power conditions to Mode 3 in an orderly manner and without challenging plant systems. The proposed change from 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> for bringing the reactor to a hot shutdown condition from full power is acceptable to the NRC staff because it is not a significant change and is based on industry operating experience.
3.1.6 Technical Conclusion for Proposed Changes to TS 3.6.3.1 The NRC staff concludes the proposed changes in the applicability statement for TS 3.6.3.1 are acceptable since they are more restrictive, as the applicability now extends to Modes 1 and 2 without exception. In addition, the occurrence of a LOCA that could lead to degraded core conditions with containment de-inerted while in Mode 3 is unlikely. Therefore, the changes proposed in TS 3.6.3.1 are acceptable and continue to meet 10 CFR 50.36(c)(2).
4.0 STATE CONSULTATION
In accordance with the Commissions regulations, the North Carolina State official was notified of the proposed issuance of the amendment on October 30, 2020. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendments change 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 amendment involves no significant hazards consideration, which was published in the Federal Register on September 8, 2020 (85 FR 55507), and there has been no public comment on such finding. 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 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 amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: A. Hon S. Smith H. Wagage Date: January 26, 2021
- by e-mail OFFICE NRR/DORL/LPLII-2/PM*
NRR/DORL/LPLII-2/LA*
NRR/DSS/STSB/BC*
NAME AHon BAbeywickrama (LRonewicz for)
VCusumano DATE 09/08/2020 09/11/2020 10/06/2020 OFFICE NRR/DSS/SCPB/BC*
OGC - NLO*
NRR/DORL/LPLII-2/BC*
NAME BWittick JMcManus UShoop DATE 10/21/20 11/16/2020 01/26/2021 OFFICE NRR/DORL/LPLII-2/PM*
NAME AHon DATE 01/26/2021