ML25119A284
| ML25119A284 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 04/27/2025 |
| From: | Natreon Jordan NRC/NRR/DORL/LPL2-2 |
| To: | Falkiewicz T, Mack J Florida Power & Light Co |
| Shared Package | |
| ML25119A283 | List: |
| References | |
| Download: ML25119A284 (1) | |
Text
OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 1
From:
Natreon Jordan To:
Mack, Jarrett; Falkiewicz, Timothy
Subject:
St. Lucie Unit 2 - Fuel Methodology LAR - FINAL RAIs Date:
Sunday, April 27, 2025 10:28:00 PM Attachments:
Final RAIs.docx Good Morning, On April 17, 2025, the U.S. Nuclear Regulatory Commission (NRC) staff issued draft Requests for Additional Information (RAIs) to Florida Power & Light Company (FPL, the licensee). The RAIs are related to the licensees submittal, dated September 11, 2024 (ML24255A118) Non-Proprietary and (ML24255A120) Proprietary, regarding proposed changes to the Technical Specifications (TS), for St. Lucie Nuclear Plant, Unit 2. The proposed license amendment would revise St. Lucie Unit 2 Technical Specification (TS) 5.6.3, Core Operating Limits Report, by updating the listing of NRC approved analytical methods used to determine the core operating limits.
Specifically, changes to the fuel thermal-mechanics, core thermal-hydraulics, emergency core cooling, nuclear design, and select design basis event analyses are proposed using NRC approved advanced codes and methods in support of a St.
Lucie Unit 2 transition to 24 month fuel cycles.
The licensee notified NRC staff that no clarification call, regarding the RAIs, was necessary and that the information requested was clearly understood. A publicly available version of the FINAL RAIs (attached) will be placed in the NRCs Agencywide Documents Access and Management System (ADAMS). The NRC staff request your response to the RAIs within 30 days of the date of this email. If you do not believe that you can meet the response date, please provide an acceptable alternate date and justification for extending the response date.
If you have any questions, please contact me at 301-415-7410 or at Natreon.Jordan@nrc.gov.
- Thanks,
-Nate
1 OFFICIAL USE ONLY - PROPRIETARY INFORMATION REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION ST. LUCIE UNIT 2 - FUEL METHODOLOGY CHANGES IN SUPPORT OF TRANSITION TO 24-MONTH FUEL CYCLES FLORIDA POWER & LIGHT COMPANY SAINT LUCIE, UNIT 2 DOCKET NO. 05000389 ISSUE DATE: N/A
Background
By letter dated September 11, 2024 (ML24255A118), Florida Power & Light Company (FPL, the licensee) submitted a license amendment request (LAR) to the U.S. Nuclear Regulatory Commission (NRC) for changes to the Technical Specifications (TS), for St. Lucie Nuclear Plant, Unit 2. The proposed license amendment would revise St. Lucie Unit 2 Technical Specification (TS) 5.6.3, Core Operating Limits Report, by updating the listing of NRC-approved analytical methods used to determine the core operating limits. Specifically, changes to the fuel thermal-mechanics, core thermal-hydraulics, emergency core cooling, nuclear design, and select design basis event analyses are proposed using NRC-approved advanced codes and methods in support of a St. Lucie Unit 2 transition to 24-month fuel cycles.
Regulatory Basis The regulation at 10 CFR 50.36(c)(5) requires that TSs include Administrative Controls. Per 10 CFR 50.36(c)(5), Administrative controls are in part the provisions relating to organization and management, procedures, recordkeeping, review and audit, and reporting necessary to assure operation of the facility in a safe manner. St. Lucie, Unit 2, TS 5.6.3 (core operating limits report) supports compliance with the reporting aspect of this regulatory requirement.
Request for Additional Information (RAI) 1 In the LAR dated September 11, 2024, the licensee identified proposed changes to TS 5.6.3 in to Enclosure 1 (St. Lucie Unit 2 TS Page Markups). Insert B to Attachment 1, added References 65 through 74. These references provide analytical methods used to determine the core operating limits. However, the NRC staff identified that Reference 71 (EMF-2310, Revision 1, Supplement 2P-A) was not described in the LAR technical evaluation section where all the other proposed changes to TS 5.6.3 were identified and addressed. As such, it is not clear if Reference 71 should remain in the list of analytical methods referenced in the proposed changes to TS 5.6.3. Therefore, the NRC staff requests the licensee review all proposed changes to TS 5.6.3 (including Reference 71) to ensure that all proposed changes are identified and addressed in the LAR technical evaluation section and vice versa.
RAI 2
In the LAR dated September 11, 2024, the licensee identified proposed changes to TS 5.6.3 in to Enclosure 1 (St. Lucie Unit 2 TS Page Markups). The NRC staff identified several editorial issues (e.g., inconsistent punctuation and spacing when compared to existing St. Lucie TS 5.6.3 references to NRC-approved analytical methods) with the markups OFFICIAL USE ONLY - PROPRIETARY INFORMATION
OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION 2
(examples listed below; not all inclusive) and requests the licensee to review the markups and make changes, as appropriate:
Titles for Insert A and Insert B refers to LIMIS (likely a misspelling of LIMITS)
Insert A:
Ref. 49 uses a single versus a double quotation mark Ref. 49 contains extra spacing Refs. 49, 50, and 51, have missing and misplaced commas Insert B:
Refs. 67, 68, 69, 70, and 71, are missing quotation marks Refs. 65, 66, 72, 73, and 74, are missing commas Refs. (multiple) contain extra spacing
RAI 3
Regulatory Basis Appendix A to Title 10 of the Code of Federal Regulations, Part 50 (10 CFR 50), General Design Criterion (GDC) 10, Reactor Design. 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 condition of normal operation, including the effects of anticipated operational occurrences.
RAI 3
The fuel rod bowing methodology applied in the Rod Ejection Accident (XN-75-32(P)(A) and Supplements 1, 2, 3, & 4, Computational Procedure for Evaluating Fuel Rod Bowing, February 1983) has the following Limitation and Condition (L&C):
If the residual DNBR penalties due to fuel rod bowing are partially or totally offset by using generic or plant-specific DNBR margin, the margin used to offset these penalties must be documented in the bases to the technical specifications and any remnant penalties must be accommodated into the technical specifications.
To address this L&C, the LAR states (in Enclosure 6 and Enclosure 3) :
Residual Departure from Nucleate Boiling Ratio (DNBR) penalties are not used to offset generic or plant-specific margins. Therefore, this L&C is met.
The resolution of the L&C does not address the concern that plant-specific or generic penalties are used to offset residual DNBR penalties due to fuel rod bowing. Instead, the resolution states plant-specific or generic margins are used without documenting their effects on the residual DNBR penalties. This L&C must be met so this fuel rod bowing methodology can be applied for the Rod Ejection Accident.
OFFICIAL USE ONLY-PROPRIETARY INFORMATION Request:
Clarify how the statement in the LAR addresses the limitation and condition related to generic or plant-specific DNBR margins offsetting residual DNBR penalties.
RAls 4-10 Regulatory Basis 1 0 CFR Part 50, Appendix A, "General Design Criteria," General Design Criterion 10, "Reactor Design," requires that the reactor core and associated coolant, control, and protection systems shall be designed with appropriate margin to ensure that Specified Acceptable Fuel Design Limits (SAFDLs) are not exceeded during any condition of normal operation, including the effects of anticipated operational occurrences. The NRC reviews and approves analysis methods to ensure that they provide a realistic or conservative result, such as determining margin to SAFDLs, and that they adhere to applicable regulatory requirements. These methods frequently contain Limitations and Conditions that an applicant must demonstrate adherence to in order to have assurance that realistic or conservative results are obtained.
RAl4 In audit meetings that took place from 2/24/2025 to 3/21/2025, the NRC staff discussed, with the applicant, several points regarding the method of adherence to ARITA Limitation and Condition 6, which re uires, in the absence of ertinent lant-s ecific data or information that licensees For the St. Lucie 24-month fuel c cle license amendment re RAIS OFFICIAL USE ONLY-PROPRIETARY INFORMATION 3
OFFICIAL USE ONLY-PROPRIETARY INFORMATION For the St. Lucie 24-month c cle LAR, that ((
RAIG The justification provided in AN P-4105P, Revision 2 re and Condition 9 discusses how RAl7 The justifications provided in AN P-4105P, Revision 2 regard in and Conditions 12 and 13 discuss the establishment of RAIS ill The explanation provided in ANP-4105P, Revision 2 regarding adherence to ARITA Limitation and Condition 15 discusses how *ustification will be established for the ((---
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ease in Ica e e evens a
ave been identified for the St. Lucie Unit 2 24-Month Cycle LAR to exhibit a prompt critical response and provide a brief discussion of the analysis approach that was erformed for these events. In this discussion, lease include the magnitudes of ((
OFFICIAL USE ONLY-PROPRIETARY INFORMATION 4
OFFICIAL USE ONLY-PROPRIETARY INFORMATION RAl9 In audit meetings conducted from 2/24/2025 to 3/21/2025, the NRC staff noted several items regarding the basis for Item 1 a under Section 2.1.3, "Methodology Clarifications" of ANP-4105P, Revision 2. Methodology Clarification Item 1a discusses the modeling of ((-
11 Please confirm the following items regarding the unceBor o o ogy arification Item 1 a:
. ((
. ((
RAI 10
The justification provided in ANP-4087, Revision 1 re ardin Condition 11 discusses ANP-10339P-Ad ich is conse
] and the assurance tha edicted in uture ses for OFFICIAL USE ONLY-PROPRIETARY INFORMATION 5