ML25100A116
| ML25100A116 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 06/12/2025 |
| From: | Samson Lee Plant Licensing Branch IV |
| To: | Reasoner C Wolf Creek |
| Lee S, 301-415-3168 | |
| References | |
| EPID L-2024-LLA-0105 | |
| Download: ML25100A116 (1) | |
Text
June 12, 2025 Mr. Cleveland Reasoner Chief Executive Officer and Chief Nuclear Officer Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KS 66839
SUBJECT:
WOLF CREEK GENERATING STATION, UNIT 1 - ISSUANCE OF AMENDMENT NO. 244 RE: REVISION TO TECHNICAL SPECIFICATION 3.2.1, HEAT FLUX HOT CHANNEL FACTOR (FQ(Z)) (FQ METHODOLOGY), TO IMPLEMENT METHODOLOGY IN PRESSURIZED WATER REACTOR OWNERS GROUP TOPICAL REPORT WCAP-17661-P-A, REVISION 1 (EPID L-2024-LLA-0105)
Dear Mr. Reasoner:
The U.S. Nuclear Regulatory Commission (NRC, the Commission) has issued the enclosed Amendment No. 244 to Renewed Facility Operating License No. NPF-42 for the Wolf Creek Generating Station, Unit 1. The amendment consists of changes to the Technical Specifications (TS) in response to your application dated July 31, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24213A335).
The amendment revises TS 3.2.1, Heat Flux Hot Channel Factor (FQ(Z)) (FQ Methodology), to implement the methodology in Pressurized Water Reactor Owners Group Topical Report WCAP-17661-P-A, Revision 1, Improved RAOC [Relaxed Axial Offset Control] and CAOC
[Constant Axial Offset Control] FQ Surveillance Technical Specifications.
Copies of the related Safety Evaluation and Notices and Environmental Findings are also enclosed., The Notice of Issuance will be included in the Commissions monthly Federal Register notice.
Sincerely,
/RA/
Samson S. Lee, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-482
Enclosures:
- 1. Amendment No. 244 to NPF-42
- 2. Safety Evaluation
- 3. Notices and Environmental Findings cc: Listserv
WOLF CREEK NUCLEAR OPERATING CORPORATION WOLF CREEK GENERATING STATION, UNIT 1 DOCKET NO. 50-482 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 244 License No. NPF-42
- 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment to the Wolf Creek Generating Station, Unit 1 (the facility) Renewed Facility Operating License No. NPF-42 filed by the Wolf Creek Nuclear Operating Corporation (the Corporation), dated July 31, 2024, 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, as amended, 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-42 is hereby amended to read as follows:
(2)
Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A, as revised through Amendment No. 244, and the Environmental Protection Plan contained in Appendix B, as revised through Amendment No.
229, both of which are attached hereto, are hereby incorporated in the license. The Corporation shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
- 3.
The license amendment is effective as of its date of issuance and shall be implemented prior to MODE 4 entry from Refueling Outage 27 (Fall 2025).
FOR THE NUCLEAR REGULATORY COMMISSION Tony Nakanishi, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Attachment:
Changes to Renewed Facility Operating License and the Technical Specifications Date of Issuance: June 12, 2025 TONY NAKANISHI Digitally signed by TONY NAKANISHI Date: 2025.06.12 11:22:27 -04'00'
ATTACHMENT TO LICENSE AMENDMENT NO. 244 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-42 WOLF CREEK GENERATING STATION, UNIT 1 DOCKET NO. 50-482 Replace the following pages of Renewed Facility Operating License No. NPF-42 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.
Renewed Facility Operating License REMOVE INSERT 4
4 Technical Specifications REMOVE INSERT 3.2-1 3.2-1 3.2-2 3.2-2 3.2-3 3.2-3 3.2-4 3.2-4 3.2-5 3.2-5 5.0-26 5.0-26
4 (5)
The Operating Corporation, pursuant to the Act and 10 CFR Parts 30, 40 and 70, to receive, possess, and use in amounts as required any byproduct, source or special nuclear material without restriction to chemical or physical form, for sample analysis or instrument calibration or associated with radioactive apparatus or components; and (6)
The Operating Corporation, pursuant to the Act and 10 CFR Parts 30, 40 and 70, to possess, but not separate, such byproduct and special nuclear materials as may be produced by the operation of the facility.
C.
This renewed operating license shall be deemed to contain and is subject to the conditions specified in the Commissions regulations in 10 CFR Chapter I 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 The Operating Corporation is authorized to operate the facility at reactor core power levels not in excess of 3565 megawatts thermal (100%
power) in accordance with the conditions specified herein.
(2)
Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A, as revised through Amendment No. 244, and the Environmental Protection Plan contained in Appendix B, as revised through Amendment No. 229, both of which are attached hereto, are hereby incorporated in the license. The Corporation shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
(3)
Antitrust Conditions Evergy Kansas South, Inc. and Evergy Metro, Inc. shall comply with the antitrust conditions delineated in Appendix C to this license.
(4)
Environmental Qualification (Section 3.11, SSER #4, Section 3.11, SSER #5)*
Deleted per Amendment No. 141.
- The parenthetical notation following the title of many license conditions denotes the section of the supporting Safety Evaluation Report and/or its supplements wherein the license condition is discussed.
Renewed License No. NPF-42 Amendment No. 244
FQ(Z) (RAOC - T(Z) Methodology) 3.2.1 Wolf Creek - Unit 1 3.2-1 Amendment No. 123, 159, 188, 244 3.2 POWER DISTRIBUTION LIMITS 3.2.1 Heat Flux Hot Channel Factor (FQ(Z)) (RAOC - T(Z) Methodology)
LCO 3.2.1 FQ(Z), as approximated by FQC(Z) and FQW(Z), shall be within the limits specified in the COLR.
APPLICABILITY:
MODE 1.
ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.
NOTE--------------
Required Action A.4 shall be completed whenever this Condition is entered prior to increasing THERMAL POWER above the limit of Required Action A.1. SR 3.2.1.2 is not required to be performed if this Condition is entered prior to THERMAL POWER exceeding 75%
RTP after a refueling.
FQC(Z) not within limit.
A.1 Reduce THERMAL POWER 1% RTP for each 1% FQC(Z) exceeds limit.
AND A.2 Reduce Power Range Neutron Flux - High trip setpoints 1% for each 1% that THERMAL POWER is limited below RTP by Required Action A.1.
AND A.3 Reduce Overpower T trip setpoints 1% for each 1% that THERMAL POWER is limited below RTP by Required Action A.1.
AND A.4 Perform SR 3.2.1.1 and SR 3.2.1.2.
15 minutes after each FQC(Z) determination 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after each FQC(Z) determination 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after each FQC(Z) determination Prior to increasing THERMAL POWER above the limit of Required Action A.1 (continued)
FQ(Z) (RAOC - T(Z) Methodology) 3.2.1 Wolf Creek - Unit 1 3.2-2 Amendment No. 123, 244 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B.
FQW(Z) not within limits.
B.1.1 Implement a RAOC operating space specified in the COLR that restores FQW(Z) to within limits.
AND B.1.2 Perform SR 3.2.1.1 and SR 3.2.1.2 if control rod motion is required to comply with the new operating space.
OR B.2.1
NOTE------------
Required Action B.2.4 shall be completed whenever Required Action B.2.1 is performed prior to increasing THERMAL POWER above the limit of Required Action B.2.1.
Limit THERMAL POWER to less than RTP and reduce AFD limits as specified in the COLR.
AND B.2.2 Reduce Power Range Neutron Flux - High trip setpoints 1% for each 1% that THERMAL POWER is limited below RTP by Required Action B.2.1.
AND 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> 72 hours 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> after each FQW(Z) determination 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after each FQW(Z) determination (continued)
FQ(Z) (RAOC - T(Z) Methodology) 3.2.1 Wolf Creek - Unit 1 3.2-3 Amendment No. 123,188,227,244 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B.
(continued)
B.2.3 Reduce Overpower T trip setpoints 1% for each 1% that THERMAL POWER is limited below RTP by Required Action B.2.1.
AND B.2.4 Perform SR 3.2.1.1 and SR 3.2.1.2.
72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after each FQW(Z) determination Prior to increasing THERMAL POWER above the limit of Required Action B.2.1 C.
Required Action and associated Completion Time not met.
C.1 Be in MODE 2.
6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />
FQ(Z) (RAOC - T(Z) Methodology) 3.2.1 Wolf Creek - Unit 1 3.2-4 Amendment No. 123, 188, 244 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.2.1.1 Verify FQC(Z) is within limit.
Once after each refueling prior to THERMAL POWER exceeding 75% RTP AND Once within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after achieving equilibrium conditions after exceeding, by 10% RTP, the THERMAL POWER at which FQC(Z) was last verified AND In accordance with the Surveillance Frequency Control Program (continued)
FQ(Z) (RAOC - T(Z) Methodology) 3.2.1 Wolf Creek - Unit 1 3.2-5 Amendment No. 123, 227,244 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.2.1.2 Verify FQW(Z) is within limit.
Once after each refueling within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after THERMAL POWER exceeds 75% RTP AND Once within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after achieving equilibrium conditions after exceeding, by 10% RTP, the THERMAL POWER at which FQW(Z) was last verified AND In accordance with the Surveillance Frequency Control Program
Reporting Requirements 5.6 Wolf Creek - Unit 1 5.0-26 Amendment No. 123, 142, 144, 158, 164, 179, 209, 213, 216, 221, 5.6 Reporting Requirements 5.6.5 CORE OPERATING LIMITS REPORT (COLR) (continued) 4.
WCAP-16009-P-A, Realistic Large Break LOCA Evaluation Methodology Using the Automated Statistical Treatment of Uncertainty Method (ASTRUM).
5.
WCAP-16045-P-A, Qualification of the Two-Dimensional Transport Code PARAGON.
6.
WCAP-16045-P-A, Addendum 1-A, Qualification of the NEXUS Nuclear Data Methodology.
7.
WCAP 10965-P-A, ANC: A Westinghouse Advanced Nodal Computer Code.
8.
WCAP-12610-P-A, VANTAGE+ Fuel Assembly Reference Core Report.
9.
WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, Optimized ZIRLO TM.
10.
WCAP-8745-P-A, Design Bases for the Thermal Power T and Thermal Overtemperature T Trip Functions.
11.
WCAP-17661-P-A, Improved RAOC and CAOC FQ Surveillance Technical Specifications.
c.
The core operating limits shall be determined such that all applicable limits (e.g., fuel thermal mechanical limits, core thermal hydraulic limits, Emergency Core Cooling Systems (ECCS) limits, nuclear limits such as SDM, transient analysis limits, and accident analysis limits) of the safety analysis are met.
d.
The COLR, including any midcycle revisions or supplements, shall be provided upon issuance for each reload cycle to the NRC.
(continued) 244
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 244 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-42 WOLF CREEK NUCLEAR OPERATING CORPORATION WOLF CREEK GENERATING STATION, UNIT 1 DOCKET NO. 50-482 Application (i.e., initial and supplements)
Safety Evaluation Date July 31, 2024, Agencywide Documents Access and Management System (ADAMS) Accession No. ML24213A335.
June 12, 2025 Principal Contributors to Safety Evaluation Charley Peabody Summer Sun Tarico Sweat
1.0 PROPOSED CHANGE
S Wolf Creek Nuclear Operating Corporation (the licensee) has requested an amendment to Renewed Facility Operating License No. NPF-42 to revise the Technical Specifications (TSs) for the Wolf Creek Generating Station, Unit 1 (Wolf Creek). The proposed amendment would modify the Wolf Creek TS 3.2.1, Heat Flux Hot Channel Factor (FQ(Z)) (FQ Methodology), to implement the methodology in Pressurized Water Reactor Owners Group (PWROG) Topical Report WCAP-17661-P-A, Revision 1, Improved RAOC [(Relaxed Axial Offset Control)] and CAOC [(Constant Axial Offset Control)] FQ Surveillance Technical Specifications, dated February 2019 (Package ML19225C138).
Additionally, the proposed amendment would modify TS 5.6.5, CORE OPERATING LIMITS REPORT (COLR), to include WCAP-17661-P-A, Revision 1, in the list of the U.S. Nuclear Regulatory Commission (NRC, the Commission) approved methodologies used to develop the COLR.
1.1 Background Information and Reason for Proposed Changes Westinghouse Electric Company LLCs (Westinghouse) Nuclear Safety Advisory Letter (NSAL)--09-5, Revision 0, (dated August 4,2009), Relaxed Axial Offset Control FQ Technical Specification Actions, notified its customers of an issue associated with the Required Actions for Condition B of NUREG-1431, Standard Technical Specifications Westinghouse Plants, Revision 3, Volume 1, Specifications, dated March 31, 2004 (ML041830612), TS 3.2.1B, Heat Flux Hot Channel Factor (FQ(Z) (RAOC W(Z) Methodology), for plants that have implemented
the RAOC methodology. Specifically, Westinghouse identified that in certain situations where transient FQ, FQW(Z), is not within its limit, the existing Required Actions may be insufficient to restore FQW(Z) to within the limit. In NSAL-09-5, Revision 1, dated September 23, 2009 (ML17167A233, not publicly available in ADAMS), Westinghouse recommended that conservative interim actions be administratively implemented in accordance with NRC Administrative Letter 98-10 (dated December 29, 1998), in addition to those required for Condition B of TS 3.2.1B in NUREG-1431 for plants using the RAOC methodology as described in the Recommended Actions section of NSAL-09-5, Revision. 1. On August 7, 2009, the licensee implemented administrative controls associated with Condition B of TS 3.2.1 to address issues in NSAL-09-5.
Westinghouse also notified its customers in NSAL-15-1, dated February 3, 2015, Heat Flux Hot Channel Factor Technical Specification Surveillance, of an issue associated with TS Surveillance Requirement (SR) 3.2.1.2 for NUREG-1431, Revision 3, dated March 31, 2004 (ML041830612). Specifically, Westinghouse identified that one aspect of the SR may not be sufficient to assure that the peaking factor assumed in the licensing basis analysis remains valid under all conditions between the instances of performance of SR 3.2.1.2. On May 14, 2015, the licensee implemented administrative controls associated with SR 3.2.1.2 to address issues in NSAL-15-1.
On March 18, 2019, the PWROG submitted the approved proprietary and non-proprietary version of WCAP-17661, Revision 1, to the NRC with TS corrections and associated TS Bases (Package ML19225C138). The NRC staff confirmed that it previously reviewed and approved WCAP-17661-P-A, Revision 1 (ML19225C081), for use with limitations to address the issues associated with TS 3.2.1 discussed in Westinghouse NSAL-09-5 and NSAL-15-1.
In accordance with the licensees LAR section 2.4, the reason for the proposed changes to TS 3.2.1 is to address the issues associated with TS 3.2.1 discussed in Westinghouse NSAL-09-5 and NSAL-15-1. The proposed TS 3.2.1 would be changed to be consistent with the revised TS 3.2.1B provided in Appendix A of the NRC-approved WCAP-17661-P-A, Revision 1.
1.2 Technical Specification 3.2.1 Changes According to the licensees LAR section 2.5, the proposed changes to TS 3.2.1 correct the issues described above in section 1.1 of this safety evaluation (SE). The changes proposed below are consistent with the TS 3.2.1 changes reviewed and approved by the NRC staff in appendix A of WCAP-17661-P-A, Revision 1.
The title of TS 3.2.1 is being changed from Heat Flux Hot Channel Factor (FQ(Z)) (FQ Methodology) to Heat Flux Hot Channel Factor (FQ(Z)) (RAOC - T(Z) Methodology).
Similarly, the header for TS 3.2.1 would change from FQ(Z) (FQ Methodology) to FQ(Z)
(RAOC - T(Z) Methodology).
A new Note is added to Condition A, which states, Required Action A.4 shall be completed whenever this Condition is entered prior to increasing THERMAL POWER above the limit of Required Action A.1. SR 3.2.1.2 is not required to be performed if this Condition is entered prior to THERMAL POWER exceeding 75% RTP
[rated thermal power] after a refueling.
Required Action A.2 would be changed from Reduce Power Range Neutron Flux - High trip setpoints 1% for each 1% FQC(Z) exceeds limit to Reduce Power Range Neutron Flux - High trip setpoints 1% for each 1% that THERMAL POWER is limited below RTP by Required Action A.1.
Required Action A.3 would be changed from Reduce Overpower T trip setpoints 1%
for each 1% FQC(Z) exceeds limit to Reduce Overpower T trip setpoints 1% for each 1% that THERMAL POWER is limited below RTP by Required Action A.1.
Required Action A.4 would be changed from Perform SR 3.2.1.1 to Perform SR 3.2.1.1 and 3.2.1.2.
Existing Required Action B.1 would be deleted and new Required Action B.1.1, B.1.2, B.2.1, B.2.2, B.2.3, and B.2.4 would be added. B.1 and B.2 actions are connected by an OR statement, all actions within B.1 and B.2 sections are connected by AND statements.
Required Action B.1.1 is to Implement a RAOC operating space specified in the COLR that restores FQW(Z) to within its limits, with a completion time of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
Required Action B.1.2 is to Perform SR 3.2.1.1 and SR 3.2.1.2 if control rod motion is required to comply with the new operating space, with a completion time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
Required Action B.2.1 contains a Note, which states that Required Action B.2.4 shall be completed whenever the Required Action B.2.1 is performed prior to increasing THERMAL POWER above the limit of Required Action B.2.1.
Required Action B.2.1 is to Limit THERMAL POWER to less than RTP and reduce AFD
[axial flux difference] limits as specified in the COLR, with a completion time of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> after each FQW(Z) determination.
Required Action B.2.2 is to Reduce Power Range Neutron Flux - High trip setpoints 1% for each 1% that THERMAL POWER is limited below RTP by Required Action B.2.1, with a completion time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after each FQW(Z) determination.
Required Action B.2.3 is to Reduce Overpower T trip setpoints 1% for each 1% that THERMAL POWER is limited below RTP by Required Action B.2.1, with a completion time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after each FQW(Z) determination.
Required Action B.2.4 is to Perform SR 3.2.1.1 and SR 3.2.1.2, with a completion time of Prior to increasing THERMAL POWER above the limit of Required Action B.2.1.
The existing Note to the Surveillance Requirements of TS 3.2.1.1, which states, During power escalation following shutdown, THERMAL POWER may be increased until an equilibrium power level has been achieved, at which a power distribution measurement is obtained, is deleted in its entirety.
The Note to SR 3.2.1.2 regarding FQC(Z) measurements is also deleted in its entirety.
Surveillance Frequency 3.2.1.2 would be changed from Once after each refueling prior to THERMAL POWER exceeding 75% RTP to Once after each refueling within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after THERMAL POWER exceeds 75% RTP.
1.3 Technical Specification 5.6.5b changes A change that would add the NRC staff-approved core operating limits analytical method WCAP-17661-P-A, Improved RAOC and CAOC FQ Surveillance Technical Specifications.
2.0 REGULATORY EVALUATION
The NRC staff has considered the following regulatory requirements and guidance during its review of the proposed changes.
Regulatory Requirements Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36, Technical specifications, details the content and information that must be included in a plants TSs. In accordance with 10 CFR 50.36(c), TSs are required to include (1) safety limits, limiting safety system settings, and limiting control settings; (2) limiting conditions for operation; (3) surveillance requirements; (4) design features; and (5) administrative controls. The COLR is part of the administrative controls, which is included in the Wolf Creek TSs in accordance with 10 CFR 50.36. The proposed changes to the Wolf Creek TSs would ensure that the administrative controls relied upon in the COLR are properly described in the TSs.
Appendix A to 10 CFR Part 50, General Design Criteria for Nuclear Power Plants, General Design Criterion (GDC) 10, Reactor design, states:
The reactor core and associated coolant, control, and protection systems shall be designed with appropriate margin to assure that specified acceptable fuel design limits are not exceeded during any conditions of normal operation, including the effects of anticipated operational occurrences.
Appendix A to 10 CFR Part 50, GDC 20, Protection system functions, states:
The protection system shall be designed (1) to initiate automatically the operation of appropriate systems including the reactivity control systems, to assure that specified acceptable fuel design limits are not exceeded as a result of anticipated operational occurrences and (2) to sense accident conditions and to initiate the operation of systems and components important to safety.
Appendix A to 10 CFR Part 50 GDC 26, Reactivity control system redundancy and capability, states, Two independent reactivity control systems of different design principles shall be provided. One of the systems shall use control rods, preferably including a positive means for inserting the rods, and shall be capable of
reliably controlling reactivity changes to assure that under conditions of normal operation, including anticipated operational occurrences, and with appropriate margin for malfunctions such as stuck rods, specified acceptable fuel design limits are not exceeded. The second reactivity control system shall be capable of reliably controlling the rate of reactivity changes resulting from planned, normal power changes (including xenon burnout) to assure acceptable fuel design limits are not exceeded. One of the systems shall be capable of holding the reactor core subcritical under cold conditions.
Based on the review of the above information, the NRC staff concluded that GDCs 10, 20, and 26 will continue to be met through implementation of the proposed changes in section 3.0 of this SE because the proposed TS changes would ensure the validity of power peaking factors assumed in the licensing basis analysis, which met the requirements of GDCs 10, 20, and 26.
Regulatory Guidance NRC Generic Letter (GL) 88-16, Removal of Cycle-Specific Parameter Limits From Technical Specifications (ML031200485), dated October 4, 1988, established the NRC position that licensees could remove cycle-specific values of certain operating limits from the TSs and maintain them in a COLR, provided that the following requirements were met: (1) use NRC-approved methodology to determine the operating limits, (2) include a list, in the TS administrative controls section, of the references used to determine the operating limits, and (3) maintain the limits in a COLR, which must be submitted to the NRC for information.
3.0 TECHNICAL EVALUATION
Section 1.1 of this SE discussed the background information and reason for the proposed changes provided by the licensee, indicating that the licensees proposed changes to TS 3.2.1 are needed to address the issues associated with TS 3.2.1 discussed in Westinghouse NSAL-09-5 and NSAL-15-1. Since the proposed TS 3.2.1 would be changed to be consistent with the revised TS 3.2.1B provided in appendix A of the NRC-approved WCAP-17661-P-A, Revision 1, the NRC staff determined that the licensee provided an adequate description of the need to update the Heat Flux Hot Channel Factor methodology. The proposed changes to TS 3.2.1 address the issues described by reformulating the transient FQ surveillance and define newly required actions to ensure that adequate margin is maintained. FQ surveillance W(Z) factors are redefined to mitigate sensitivity to differences between the measured and predicted steady-state power shapes. The new factors, called T(Z) factors, primarily characterize the maximum transient P(Z), that is, the maximum expected values of the normalized core average axial power shape resulting from nonequilibrium operation. With the proposed changes, the radial FXY(Z) peaking factors would be measured and multiplied by the T(Z) factors to obtain the measured FQW(Z), which is the transient FQ(Z). Further, the NRC staff found that this proposed change will also improve the accuracy of part-power surveillances because the surveillance axial power shape is not used to determine the measured transient FQ(Z). Use of the surveillance axial power shape in the part power transient FQ(Z) measurement is a major source of the over-measurement that can lead to anomalous reductions in transient FQ margin for part-power surveillances.
As described in section 3.0 of the LAR, the proposed changes would permit multiple RAOC operating spaces to be defined in the COLR. The COLR will include T(Z) functions for each
RAOC operating space, which is defined as a unique combination of AFD limits and bank insertion limits. If there is a measured transient FQ violation, then a more restrictive RAOC operating space can be selected from the COLR that provides the required margin for future non-equilibrium operation. This retains the feature of using an AFD reduction to gain margin but in a manner that ensures that appropriate margin is recovered. If none of the RAOC operating spaces included in the COLR provides the required margin, then limits on thermal power and AFD must be implemented. These limits are specified in the COLR.
The NRC staff reviewed the licensees submittal as well as the referenced methodology, NRC-approved WCAP-17661-P-A, dated February 2019 (ML19225C079), and found that the proposed TS changes are consistent with the NRC-approved methodology with the deviations discussed in section 3.1 of this SE, and compliance with the limitations imposed in the SE for use of WCAP-17661-P-A discussed in section 3.2 of this SE.
3.1 Deviations from the Approved Technical Specification Markup The Completion Times for Required Actions B.2.1, B.2.2, and B.2.3 contain a deviation from those contained in appendix A of WCAP-17661-P-A. For example, the proposed Completion Times for the Required Actions include the phrase after each FQW(Z) determination, while appendix A does not have the phrase. As stated on page 8 of attachment 1 to the LAR, the licensee indicated that the added phrase is necessary to specify the appropriate timing of conducting Required Actions B.2.1, B.2.2, and B.2.3, because the THERMAL POWER initially determined by Required Action B 2.1 may be affected by the subsequent determination of FQW(Z) that is not within the limit when Required Action B 2.4 is performed and could require additional power reduction within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of subsequent FQW(Z) determination, if necessary to comply with the decreased THERAL POWER level. The licensee stated, and the NRC staff agreed, that the added phrase, after each FQW(Z) determination, to Completion Times for Required Actions B 2.1, B 2.2 and B 2.3 would ensure that these Required Actions apply after each subsequent determination of FQW(Z) during performance of Required Action B 2.4. The NRC staff also found that the added phrase is similar to the phrase after each FQC(Z) determination that is contained in Completion Times for Required Actions A.1, A.2, and A.3 associated with FQC(Z). Therefore, the NRC staff concluded that the deviations within Required Actions B.2.1, B.2.2, and B.2.3 improve clarity without any impact on the safety aspects of the methodology, therefore, are acceptable.
3.2 WCAP-17661-P-A Revision 1 Approval Limitations There are two limitations included in the NRC SE as conditions to approving the use of WCAP-17661-P-A.
First, the NRC staff places a limitation on the use of AXY and AQ when performing RAOC and COAC W(Z) surveillances. Specifically, the first limitation require that, (1) AXY or AQ calculations must be performed using NRC-approved methods, (2) depletion calculations must be similar to the original design calculation, and (3) AQ is only acceptable if the surveillance axial offset is within 1.5 percent of the target axial offset, and that the limiting FQW(Z) does not lie within a rodded elevation at the time of the surveillance.
The application addresses the first two criteria using guidance in the TS bases. The NRC staff found that this guidance is consistent with the sample TS bases markup provided in the SE for WCAP-17661-P-A. Specifically, the Best Estimate Analyzer for Core Operations - Nuclear (BEACON) and Advanced Nodal Code (ANC) methods in use at Wolf Creek meet the first and
second conditions. The NRC staff determined that the third condition is not applicable because the NRC staff found in section 1.3.2 of the SE approving WCAP-17661 (ML18298A321) that it only applies to CAOC methods, whereas the licensee is only seeking to implement the RAOC methodology.
Second, the NRC staff requires a 50 percent power level limitation because 50 percent final power level reduction in the event of failed FQ surveillance is not located in the TSs, but the Bases and the COLR, therefore a final power level of 50 percent must be implemented on a plant-specific basis in order to use the WCAP-17661-P-A methodology. The NRC staff identified during its review of the sample documents that the licensee included 50 percent final power level reduction appropriately.
Therefore, the NRC staff concluded that all limitations and conditions to implement the WCAP-17661-P-A, Revision 1, methodology are appropriately satisfied.
3.3 Technical Evaluation Conclusion
Based on the evaluation in sections 3.0, 3.1 and 3.2 of this SE mentioned above, the NRC staff concluded that the proposed TS changes are acceptable, because (1) the changes are consistent with the NRC-approved methodology in WCAP-17661-P-A, Revision 1, (2) the changes are consistent with the approved TS markups, TS bases markups, and COLR markups, and (3) the ANC and BEACON plant monitoring systems currently in use at Wolf Creek are fully capable of implementing the methodology as proposed and continue to meet the requirements of 10 CFR 50.36.
4.0 CONCLUSION
Based on the considerations discussed above, the NRC staff concludes 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.
NOTICES AND ENVIRONMENTAL FINDINGS RELATED TO AMENDMENT NO. 244 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-42 WOLF CREEK NUCLEAR OPERATING CORPORATION WOLF CREEK GENERATING STATION, UNIT 1 DOCKET NO. 50-482 Application (i.e., initial and supplements)
Safety Evaluation Date July 31, 2024, Agencywide Documents Access and Management System (ADAMS) Accession No. ML24213A335 June 12, 2025
1.0 INTRODUCTION
Wolf Creek Nuclear Operating Corporation (the licensee) has requested an amendment to Renewed Facility Operating License No. NPF-42 to revise the Technical Specifications (TS) for the Wolf Creek Generating Station, Unit 1 (Wolf Creek). The proposed amendment would modify the Wolf Creek TS 3.2.1, Heat Flux Hot Channel Factor (FQ(Z)) (FQ Methodology), to implement the methodology in Pressurized Water Reactor Owners Group Topical Report WCAP-17661-P-A, Revision 1, Improved RAOC [Relaxed Axial Offset Control] and CAOC
[Constant Axial Offset Control] FQ Surveillance Technical Specifications, dated February 2019.
(Agencywide Documents Access and Management System (ADAMS) Accession No.:
ML19225C079). Additionally, the proposed amendment modifies TS 5.6.5, CORE OPERATING LIMITS REPORT (COLR), to include WCAP-17661-P-A, Revision 1, in the list of the U.S.
Nuclear Regulatory Commission (NRC, the Commission) approved methodologies used to develop the COLR.
2.0 STATE CONSULTATION
In accordance with the NRCs regulations, the Kansas State official was notified of the proposed issuance of the amendment on February 20, 2025 (ML25143A018). The State official had no comments on May 22, 2025 (ML25143A017).
3.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 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 that the amendment involves no significant hazards consideration, and there has been no public comment on such finding published in the Federal Register on October 1, 2024 (89 FR 79971).
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.
- via memo dated OFFICE NRR/DORL/LPL4/PM NRR/DORL/LPL4/LA NRR/DSS/STSB/BC*
NRR/DSS/SNSB/BC*
NAME SLee PBlechman SMehta DMurdock DATE 04/10/2025 04/23/2025 03/27/2025 02/20/2025 OFFICE OGC - NLO NRR/DORL/LPL4/BC NRR/DORL/LPL4/PM NAME KWilson TNakanishi SLee DATE 06/03/2025 06/12/2025 06/12/2025