ML25231A001
| ML25231A001 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 08/26/2025 |
| From: | Robert Kuntz NRC/NRR/DORL/LPL3 |
| To: | Tony Brown Vistra Operations Company |
| Kuntz R, NRR/DORL/LPL3 | |
| References | |
| EPID L-2025-LLA-0042 | |
| Download: ML25231A001 (1) | |
Text
August 26, 2025 Mr. Terry J. Brown Vistra Operations Company LLC c/o Davis-Besse Nuclear Power Station Mail Stop P-DB-3080 5501 N. State Route 2 Oak Harbor, OH 43449-9760
SUBJECT:
DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO. 1 - ISSUANCE OF AMENDMENT NO. 309 RE: TSTF-501 RELOCATE STORED FUEL OIL AND LUBE OIL VOLUME VALUES TO LICENSEE CONTROL (EPID L-2025-LLA-0042)
Dear Mr. Brown:
The U.S. Nuclear Regulatory Commission has issued the enclosed Amendment No. 309 to Renewed Facility Operating License No. NPF-3 for the Davis-Besse Nuclear Power Station, Unit No. 1, in response to your application dated February 26, 2025.
The amendment revises Technical Specification (TS) 3.8.3, Diesel Fuel Oil, Lube Oil, and Starting Air, Surveillance Requirement (SR) 3.8.3.1, and SR 3.8.3, by removing the current stored diesel fuel and lube oil numerical volume requirements and replacing them with duration-based diesel operating time requirements, consistent with TS Task Force (TSTF) traveler TSTF 501, Revision 1, Relocate Stored Fuel Oil and Lube Oil Volume Values to Licensee Control.
A copy of the Safety Evaluation is also enclosed. A Notice of Issuance will be included in the Commissions monthly Federal Register notice.
Sincerely,
/RA/
Robert Kuntz, Senior Project Manager Plant Licensing Branch III Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-346
Enclosures:
- 1. Amendment No. 309 to Renewed License No. NPF-3
- 2. Safety Evaluation cc: Listserv
VISTRA OPERATIONS COMPANY LLC AND ENERGY HARBOR NUCLEAR GENERATION LLC DOCKET NO. 50-346 DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO. 1 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 309 Renewed License No. NPF-3
- 1.
The U.S. Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment filed by Vistra Operations Company LLC. (the licensee), dated February 26, 2025, 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. NPF-3 is hereby amended to read as follows:
(2)
Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 309, are hereby incorporated in the renewed license. Vistra Operations Company LLC shall operate the facility in accordance with the Technical Specifications.
- 3.
This license amendment is effective as of its date of issuance and shall be implemented within 90 days of the date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION Ilka Berrios, Acting Chief Plant Licensing Branch III Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Attachment:
Changes to the Renewed Facility License and Technical Specifications Date of Issuance: August 26, 2025 ILKA BERRIOS Digitally signed by ILKA BERRIOS Date: 2025.08.26 12:57:54 -04'00'
ATTACHMENT TO LICENSE AMENDMENT NO. 309 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-3 DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO. 1 DOCKET NO. 50-346 Replace the following pages of the Renewed Facility Operating License No. NPF-3 and Appendix A, Technical Specifications, with the attached revised pages. The revised pages are identified by amendment number and contain vertical lines indicating the areas of change.
Renewed Facility Operating License No. NPF-3 REMOVE INSERT L-5 L-5 Technical Specifications REMOVE INSERT 3.8.1-6 3.8.1-6 3.8.3-1 3.8.3-1 3.8.3-2 3.8.3-2 3.8.3-3 3.8.3-3
L-5 Renewed License No. NPF-3 Amendment No. 309 2.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 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 Vistra Operations Company LLC is authorized to operate the facility at steady state reactor core power levels not in excess of 2817 megawatts (thermal). Prior to attaining the power level, Toledo Edison Company shall comply with the conditions identified in Paragraph (3) (o) below and complete the preoperational tests, startup tests and other items identified in Attachment 2 to this license in the sequence specified. Attachment 2 is an integral part of this renewed license.
(2)
Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 309, are hereby incorporated in the renewed license.
Vistra Operations Company LLC shall operate the facility in accordance with the Technical Specifications.
(3)
Additional Conditions The matters specified in the following conditions shall be completed to the satisfaction of the Commission within the stated time periods following the issuance of the renewed license or within the operational restrictions indicated. The removal of these conditions shall be made by an amendment to the renewed license supported by a favorable evaluation by the Commission:
(a)
Vistra Operations Company LLC shall not operate the reactor in operational Modes 1 and 2 with less than three reactor coolant pumps in operation.
(b)
Deleted per Amendment 6 (c)
Deleted per Amendment 5
AC Sources - Operating 3.8.1 Davis-Besse 3.8.1-6 Amendment 309 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.8.1.3
NOTES-----------------------------
- 1. EDG loadings may include gradual loading as recommended by the manufacturer.
- 2. Momentary transients outside the load range do not invalidate this test.
- 3. This Surveillance shall be conducted on only one EDG at a time.
- 4. This SR shall be preceded by and immediately follow, without shutdown, a successful performance of SR 3.8.1.2 or SR 3.8.1.8.
Verify each EDG is synchronized and loaded and operates for 60 minutes at a load 2340 kW and 2600 kW.
In accordance with the Surveillance Frequency Control Program SR 3.8.1.4 Verify each day tank contains 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> of fuel oil.
In accordance with the Surveillance Frequency Control Program SR 3.8.1.5 Check for and remove accumulated water from each day tank.
In accordance with the Surveillance Frequency Control Program SR 3.8.1.6 Verify interval between each sequenced load block is within +/- 10% of design interval for each emergency load sequencer and each emergency time delay relay.
In accordance with the Surveillance Frequency Control Program
Diesel Fuel Oil, Lube Oil, and Starting Air 3.8.3 Davis-Besse 3.8.3-1 Amendment 309 3.8 ELECTRICAL POWER SYSTEMS 3.8.3 Diesel Fuel Oil, Lube Oil, and Starting Air LCO 3.8.3 The stored diesel fuel oil, lube oil, and starting air subsystem shall be within limits for each required emergency diesel generator (EDG).
APPLICABILITY:
When associated EDG is required to be OPERABLE.
ACTIONS
NOTE-----------------------------------------------------------
Separate Condition entry is allowed for each EDG.
CONDITION REQUIRED ACTION COMPLETION TIME A. One or more EDGs with fuel level less than a 7 day supply and greater than a 6 day supply in storage tank.
A.1 Restore fuel oil level to within limits.
48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> B. One or more EDGs with lube oil inventory less than a 7 day supply and greater than a 6 day supply.
B.1 Restore lube oil inventory to within limits.
48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> C. One or more EDGs with stored fuel oil total particulates not within limit.
C.1 Restore fuel oil total particulates to within limits.
7 days D. One or more EDGs with new fuel oil properties not within limits.
D.1 Restore stored fuel oil properties to within limits.
30 days
Diesel Fuel Oil, Lube Oil, and Starting Air 3.8.3 Davis-Besse 3.8.3-2 Amendment 309 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME E. One or more EDGs with required starting air receiver pressure
< 210 psig and 139 psig.
E.1 Restore starting air receiver pressure to 210 psig.
48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> F. Required Action and associated Completion Time of Condition A, B, C, D, or E not met.
OR One or more EDGs with diesel fuel oil, lube oil, or starting air subsystem not within limits for reasons other than Condition A, B, C, D, or E.
F.1 Declare associated EDG inoperable.
Immediately SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.3.1 Verify each fuel oil storage tank contains a 7 day supply of fuel.
In accordance with the Surveillance Frequency Control Program SR 3.8.3.2 Verify lube oil inventory for each EDG is a 7 day supply of lube oil.
In accordance with the Surveillance Frequency Control Program
Diesel Fuel Oil, Lube Oil, and Starting Air 3.8.3 Davis-Besse 3.8.3-3 Amendment 309 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.8.3.3 Verify fuel oil properties of new and stored fuel oil are tested in accordance with, and maintained within the limits of, the Diesel Fuel Oil Testing Program.
In accordance with the Diesel Fuel Oil Testing Program SR 3.8.3.4 Verify each required EDG air start receiver pressure is 210 psig.
In accordance with the Surveillance Frequency Control Program SR 3.8.3.5 Check for and remove accumulated water from each fuel oil storage tank.
In accordance with the Surveillance Frequency Control Program
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 309 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-3 VISTRA OPERATIONS COMPANY LLC AND ENERGY HARBOR NUCLEAR GENERATION LLC DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO. 1 DOCKET NO. 50-346
1.0 INTRODUCTION
By application dated February 26, 2025 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML25058A170), Vistra Operations Company LLC (the licensee) requested changes to the technical specifications (TS) for Davis-Besse Nuclear Power Station, Unit No. 1 (Davis-Besse).
The proposed changes would revise TS 3.8.3, Diesel Fuel Oil, Lube Oil, and Starting Air, Surveillance Requirement (SR) 3.8.3.1 (verification of fuel oil storage tank volume), and SR 3.8.3.2 (verification of lube oil inventory volume), by removing the current stored diesel fuel and lube oil numerical volume requirements and replacing them with duration-based diesel operating time requirements, consistent with TS Task Force (TSTF) traveler TSTF 501, Revision 1, Relocate Stored Fuel Oil and Lube Oil Volume Values to Licensee Control (ML090510686).
The availability of this TS improvement was published in the Federal Register on May 26, 2010 (75 FR 29588), as part of the consolidated line item improvement process (CLIIP). The licensee also proposed changes that would revise TS 3.8.1, AC [alternating current] Sources -
Operating, SR 3.8.1.4 (verification of the fuel volume in each emergency diesel generator (EDG) day tank) to replace the specific day tank numerical volume requirements with a duration-based diesel operating time requirement.
1.1
System Description
The standby AC power sources are a part of the primary success path, and function or actuate to mitigate a design basis accident or transient that either assumes the failure of, or presents a challenge to, the integrity of a fission product barrier. Diesel fuel and lube oil requirements are retained in the TS as a limiting condition for operation (LCO) under Title 10 of the Code of Federal Regulations (10 CFR) 50.36(c)(2)(i) because they support the operation of the standby AC power sources.
The Davis-Besse standby AC power system is powered by two EDGs capable of an automatic start at any time and capable of continued operation at rated load, voltage, and frequency until manually stopped. Each EDG is provided with storage tanks having a fuel capacity sufficient to operate for a period of 7 days while the EDG is supplying maximum post loss-of-coolant-accident load demand. The maximum load demand is calculated assuming that at least two EDGs are available. This onsite fuel capacity is sufficient to operate the EDGs for longer than the time to replenish the onsite supply from outside sources. Diesel fuel is transferred from the storage tank to the day tank by a submersed transfer pump inside each storage tank. Each storage tank is installed above ground.
The EDG lubrication system is designed to provide sufficient lubrication to permit proper operation of its associated EDG under all loading conditions. The system is required to circulate the lube oil to the EDGs diesel engine working surfaces and to remove excess heat generated by friction during operation. Each EDGs engine oil sump typically has an inventory of lube oil capable of supporting a minimum of 7 days of operation. This supply is sufficient to allow the operator to replenish lube oil from outside sources.
1.2 Description of the Proposed Changes The proposed changes, described in the license amendment request (LAR), would revise conditions and SRs in TS 3.8.3, Diesel Fuel Oil, Lube Oil, and Starting Air, and an SR in TS 3.8.1, AC Sources - Operating, by removing the current stored diesel fuel oil volume and lube oil inventory numerical requirements and replacing them with duration based EDG operating time requirements. The proposed changes would mean that the volume necessary to meet the TS duration requirements may be modified under licensee control. The specific TS changes are described in the following sections.
Consistent with TSTF-501, the licensee proposed replacing the volumetric requirements with the duration-based EDG operating times required by the current licensing basis for Davis-Besse.
1.2.1 Proposed Changes to TS 3.8.3 Actions Table Conditions A and B Conditions A and B of TS LCO 3.8.3, Diesel Fuel Oil, Lube Oil, and Starting Air, would be revised in the actions table. Currently, conditions A and B apply when the stored diesel fuel and lube oil numerical volume requirements are not met. As discussed in the TS bases, the numerical diesel fuel volume requirement is based on volumes of less than a 7-day supply, but greater than a 6-day supply. The numerical EDG lube oil inventory requirement in condition B would apply for a volume of less than a 7-day supply, but greater than a 6-day supply. The proposed amendment would remove the numerical volumetric requirements from the TS and replace them with duration based requirements.
1.2.2 Proposed Changes to SR 3.8.3.1, SR 3.8.3.2, and SR 3.8.1.4 Currently, SR 3.8.3.1 requires the licensee to verify that each fuel storage tank contains a volume greater than or equal to 32,000 gallons of fuel. SR 3.8.3.2 requires the licensee to verify that the lube oil inventory volume is greater than or equal to 260 gallons for each EDG. SR 3.8.1.4 requires the licensee to verify that each EDGs day tank contains a volume greater than or equal to 4,000 gallons of fuel oil supply. The proposed amendment would remove the numerical volume requirements from these SRs. SR 3.8.3.1 would be revised to require verification that the stored diesel fuel oil inventory is greater than or equal to a 7-day supply. For SR 3.8.3.2, it would require verification that the lube oil inventory is greater than or equal to a 7-day supply. SR 3.8.1.4 would be revised to require the licensee to verify that each day tank contains a minimum 20-hour supply of fuel.
1.2.3 Licensee Identified Variation from TSTF-501 In the LAR, the licensee proposed a variation from TSTF 501, Revision 1, to remove the fuel volume requirement for the day tanks in SR 3.8.1.4 and replace it with a durational requirement.
2.0 REGULATORY EVALUATION
2.1 Regulatory Requirements The regulation in 10 CFR 50.36, Technical specifications, provides the regulatory requirements for the content of the TS. It requires, in part, that a summary statement of the bases for such specifications shall be included by applicants for a license authorizing operation of a production or utilization facility. Specifically, 10 CFR 50.36(c) requires that TS include items in five specific categories related to station operation. These categories are (1) safety limits, limiting safety system settings, and limiting control settings; (2) LCOs; (3) SRs; (4) design features; and (5) administrative controls.
The regulation in 10 CFR 50.36(c)(2)(i), Limiting conditions for operation, states, in part, that TS will include LCOs, which are the lowest functional capability or performance levels of equipment required for safe operation of the facility. Section 50.36(c)(2)(i) further states that
[w]hen a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the technical specifications until the condition can be met.
The regulation in 10 CFR 50.36(c)(3), Surveillance requirements, states that [s]urveillance requirements are requirements related to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions for operation will be met.
The regulation at 10 CFR 50.36(a)(1) states that [a] summary statement of the bases or reasons for such specifications, other than those covering administrative controls, shall also be included in the application, but shall not become part of the technical specifications.
2.2 Guidance Regulatory Guide 1.137, Revision 1, Fuel Oil Systems for Standby Diesel Generators (ML003740180), provides guidance that describes a method acceptable to the U.S. Nuclear Regulatory Commission (NRC, the Commission) staff for complying with the Commissions regulations regarding fuel oil systems for standby EDGs and endorses American National Standards Institute (ANSI) N195 1976, Fuel Oil Systems for Standby Diesel-Generators, with certain limitations. RG 1.137, Section C.1.c sets forth two methods for the calculation of fuel oil storage requirements as described in ANSI N195 1976, Section 5.4 Calculation of Fuel Oil Storage Requirements. These methods are: (1) calculations based on the assumption that the EDG operates continuously for 7 days at its rated capacity, and (2) calculations based on the time dependent loads of the EDG. If the time dependent load method is used, the minimum required capacity should include the capacity to power engineered safety features.
The NRC approved traveler TSTF 501, Revision 1, Relocate Stored Fuel Oil and Lube Oil Volume Values to Licensee Control (ML090510686), provides an acceptable method of modifying the stored fuel oil and lube oil requirements contained in the standard TS. Though the TSTF 501 traveler was developed based on changes to Revision 3 of NUREG 1430, Standard Technical Specifications for Babcock and Wilcox Plants, the NRC staffs review of this LAR includes consideration of whether the proposed changes are consistent with the latest revision.
NUREG 1430, Volume 1, Revision 5 (ML21272A363), provides example TS LCOs and acceptable remedial actions that meet the requirements in 10 CFR 50.36(c)(2)(i) for a standard plant design.
3.0 TECHNICAL EVALUATION
The licensee assessed the model safety evaluation (SE) (ML100850069), which was published in the Federal Register on May 26, 2010 (75 FR 29588), as part of the CLIIP notice of availability. The licensee concluded, as stated in the enclosure to the LAR, that the justifications presented in the model SE are applicable to Davis-Besse and therefore justify these amendments.
Each EDG is provided with a fuel capacity sufficient to operate that EDG for a period of 7 days.
This onsite fuel oil capacity is sufficient to operate the EDG long enough to place Davis-Besse in a shutdown condition and to bring in replenishment fuel oil from offsite sources.
The standby AC power sources (i.e., the EDGs), are a part of the primary success path and function or actuate to mitigate a design-basis accident or transient that either assumes the failure of, or presents a challenge to the integrity of, a fission product barrier. Requirements for diesel fuel oil and lube oil supplies are retained in the TS under 10 CFR 50.36(c)(2)(i) because they support the operation of the standby AC power sources.
The proposed changes would revise SRs 3.8.3.1, 3.8.3.2, and 3.8.1.4 and TS 3.8.3 action statements by removing the current stored diesel fuel oil and lube oil numerical volume requirements from the TS and replacing them with the associated duration-based diesel operating times. These changes would permit the fuel and lube oil volumes necessary to support a duration-based EDG operating time to be modified under licensee control pursuant to 10 CFR 50.59, Changes, tests and experiments. The NRC staffs evaluation of the proposed TS changes is provided in the following sections.
3.1 NRC Staff Evaluation of Proposed Changes to TS 3.8.3 Actions Table Conditions A and B Currently, condition A of TS 3.8.3 is entered when the fuel volume requirement is not met, and condition B is entered when the lube oil inventory requirement is not met. The current TS Bases state that the numerical volume requirements in conditions A and B are based on volumes less than a 7-day supply, but greater than a 6-day supply. The proposed changes would remove the numerical volumetric requirements from the TSs and would modify conditions A and B to replace them with duration-based diesel operating time requirements, such that condition A is entered when the stored fuel oil inventory is less than a 7-day supply, but greater than a 6-day supply, and condition B is entered when the lube oil inventory is less than a 7-day supply, but greater than a 6-day supply for one or more EDGs.
As described in Section 3.2 below, the licensee stated in the LAR that the stored diesel fuel and lube oil numerical volumes sufficient to meet the duration-based operating time requirements will be calculated using ANSI N195-1976, and the volumes are based on EDG manufacturers consumption values for the run-time of the EDGs. The use of this methodology will ensure that the supplies of stored diesel fuel oil and lube oil for each EDG that dictate condition entry will continue to be calculated in accordance with NRC-approved methods.
Based on the above evaluation, the NRC staff concludes that the changes to the TS 3.8.3 Actions table are acceptable.
3.2 NRC Staff Evaluation of Proposed Changes to SRs 3.8.3.1, 3.8.3.2, and 3.8.1.4 Currently, SR 3.8.3.1 and SR 3.8.3.2 require the licensee to verify that the stored diesel fuel oil and lube oil numerical volume requirements, respectively, are met. SR 3.8.1.4 requires the licensee to verify that each day tank contains the required volume of diesel fuel.
The licensee proposed revising SR 3.8.3.1 and SR 3.8.3.2 to reflect the change from numerical volume requirements to durational requirements made in the TS 3.8.3 Actions table.
Specifically, SRs 3.8.3.1 and 3.8.3.2 would be revised to require availability of a 7-day supply of fuel and lube oil for each EDG, respectively, rather than a specified numerical volume. As a result, SR 3.8.3.1 and SR 3.8.3.2 would require the licensee to verify that the combined volume of the fuel oil storage tanks and the lube oil inventory are each greater than or equal to a 7-day supply for an EDG.
The licensee also proposed revising SR 3.8.1.4, which contains the EDG day tank volumetric requirement. The proposed change to SR 3.8.1.4 is similar to the proposed change for SR 3.8.3.1 in that the numerical volume requirements would be replaced with durational requirements. The revised SR 3.8.1.4 would require the licensee to verify that the stored diesel fuel oil volume in each day tank is greater than or equal to a 20-hour supply of fuel. The licensees proposed inclusion of changes to the day tank storage requirements in the LAR is identified as a variation in section 1.2.3 of this SE.
In the enclosure to the LAR, the licensee described how the volumes of fuel and lube oil necessary to support operation of the standby DGs are calculated:
The specific volume of fuel oil equivalent to a 7 and 6-day supply is calculated using the NRC-approved methodology described in Regulatory Guide 1.137, Revision 1, Fuel-Oil Systems for Standby Diesel Generators and ANSI N195 1976, Fuel Oil Systems for Standby Diesel-Generators. The specific volume of lube oil equivalent to a 7-day and 6-day supply is based on the diesel generator manufacturers consumption values for the run time of the diesel generator.
The methodology in ANSI N195-1976 discusses how the stored diesel fuel oil requirement should be calculated based upon the EDGs operating at the minimum required capacity for the plant condition that is most limiting for the calculation of such capacity. One method for calculating the stored diesel fuel oil supply in ANSI N195-1976 takes into account the time dependence of EDG loads. That is, if EDG loads increase or decrease during the event, the load changes should be included in the required fuel oil storage calculation. If the design includes provisions for an operator to supply power to equipment other than the minimum required for the plant condition, such additional loads should be included in the calculation of required fuel oil storage capacity. Revision 1 of RG 1.137 supplements the above by stating that for the time-dependent load method, the minimum required capacity should include the capacity to power the engineered safety features. A minimum margin of 10 percent shall be added to the calculated storage requirement if the alternate conservative calculation discussed below is not used.
Another method for calculating the stored diesel fuel supply, which is more conservative than the time-dependent load method, is to calculate the storage capacity by assuming that the diesel engine operates continuously for 7 days at its rated capacity. Both calculation methods shall include an explicit allowance for fuel consumption required by periodic testing. This includes the fuel required for operation of the engine at the minimum loads specified by the engine manufacturer. Since both methods described in ANSI N195-1976 are approved for use in RG 1.137, Revision 1, and the licensee calculates the volume of fuel in accordance with RG 1.137, Revision 1, the NRC staff has reasonable assurance that the volume of fuel oil calculated by the licensee will meet the duration-based limits proposed in SR 3.8.3.1 and SR 3.8.1.4.
One variable used in both stored diesel fuel calculation methods is the fuel consumption rate.
The property of diesel fuel oil having the most significant effect on the fuel oil consumption rate is the energy content (heating value) of the fuel oil. Standards exist that correlate the energy content to the fuel oils American Petroleum Institute (API) gravity or absolute specific gravity. At a minimum, licensees calculate the required fuel oil storage values for their plants assuming the most limiting API gravity or absolute specific gravity, and therefore, the most limiting fuel oil energy content. As long as the fuel placed in the storage tank is within the API gravity range or absolute specific gravity range specified by the licensee, the calculations of fuel consumption and required stored volume remain valid. Current SR 3.8.3.3 requires new fuel oil to be tested in accordance with, and maintained within the limits of current TS 5.5.12, Diesel Fuel Oil Testing Program, to verify that the fuel oils API gravity or absolute specific gravity is within the range assumed in the diesel fuel oil consumption calculations.
The lube oil inventory equivalent to a 7-day supply, as well as the 6-day supply associated with TS 3.8.3 Condition B, is based on the EDG manufacturer consumption values for the run time of the EDG.
Accordingly, the NRC staff finds that the above methods used by the licensee still provide reasonable assurance that the necessary quality of systems and components are maintained, that facility operation will be within safety limits, and that the LCOs will be met, consistent with 10 CFR 50.36(c)(3). Therefore, the changes to SRs 3.8.3.1, 3.8.3.2, and 3.8.1.4 are acceptable.
3.4 Technical Conclusion The proposed changes will continue to require that the appropriate volumes of stored diesel fuel oil and lube oil are maintained. The proposed changes to the TS 3.8.3 actions table continue to provide assurance that the lowest functional capability or performance levels of equipment required for safe operation of the facility will continue to be met. Conditions A and B of the TS 3.8.3 actions table continue to provide acceptable remedial actions to follow until LCO 3.8.3 can be met. The NRC staff concludes that replacement of the TS numerical value volume requirements with durational requirements does not change the current plant configuration, the current volume requirements, or the current basis for fuel oil and lube oil volume requirements.
Therefore, the changes to TS 3.8.3 actions table will continue to meet 10 CFR 50.36(c)(2)(i) and are acceptable.
In addition, the proposed changes to SRs 3.8.3.1, 3.8.3.2, and 3.8.1.4 continue to provide assurance that the necessary quality of systems and components is maintained, the facility will be within safety limits, and that the LCO will be met. The revised SRs will continue to meet 10 CFR 50.36(c)(3) and are therefore acceptable.
4.0 STATE CONSULTATION
In accordance with the Commissions regulations, the Ohio State official was notified of the proposed issuance of the amendment on August 18, 2025. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
This amendment changes a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding on April 15, 2025 (90 FR 15727), that the amendment involves no significant hazards consideration 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 amendment.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) there is reasonable assurance that such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: K. West, NRR Date of Issuance: August 26, 2025
ML25231A001 NRR-058 OFFICE NRR/DORL/LPL3/PM NRR/DORL/LPL3/LA NRR/DSS/STSB/BC NAME RKuntz SLent ARussell (A)
DATE 8/18/2025 8/20/25 8/15/2025 OFFICE NRR/DORL/LPL3/BC(A)
NRR/DORL/LPL3/PM NAME IBerrios RKuntz DATE 8/26/2025 8/26/2025