ML23318A095

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Request for Additional Information (E-mail Dated 11/14/2023) LAR to Revise TSs Related to Framatome Gaia Fuel
ML23318A095
Person / Time
Site: Millstone Dominion icon.png
Issue date: 11/14/2023
From: Richard Guzman
NRC/NRR/DORL/LPL1
To: Sinha S
Dominion Energy Nuclear Connecticut
References
EPID L-2023-LLA-0074
Download: ML23318A095 (5)
v • d • e


Text

From: Richard Guzman To: Shayan.Sinha@dominionenergy.com Bcc: Richard Guzman

Subject:

Millstone Power Station, Unit 3 - REQUEST FOR ADDITIONAL INFORMATION Re: LAR to Revise TSs for Reactor Core Safety Limits, Fuel Assemblies and COLR related to Framatome GAIA Fuel (EPID: L-2023-LLA-0074)

Date: Tuesday, November 14, 2023 8:42:00 AM Attachments: Millstone TS Fuel Transition FINAL RAIs (PUBLIC) 11-14-2023_Redacted.pdf

Shayan,

On October 20, 2023, the U.S. Nuclear Regulatory Commission (NRC) staff sent Dominion Energy Nuclear Connecticut, Inc. (DENC, the licensee) the subject Request for Additional Information (RAI) as a draft e-mail. This RAI is regarding the licensees May 23, 2023 (ML23145A195), license amendment request to revise the technical specifications (TSs) for Millstone Power Station, Unit No. 3 (Millstone 3). The LAR proposes to revise the Millstone 3 TSs to support the use of Framatome GAIA fuel with M5' fuel cladding material, which is currently scheduled for insertion into the Millstone 3 reactor during the spring 2025 refueling outage. The proposed TS changes include updating the reactor core safety limits (TS 2.1.1.2), fuel assemblies design features (TS 5.3.1), and list of approved methodologies for the Core Operating Limits Report (TS 6.9.1.6.b).

The NRC staff and DENC held a conference call on November 6, 2023, to discuss clarifications on the draft RAI. As discussed on the call, please provide a response to these questions within 45 days of this e-mail communication or no later than December 29, 2023.

Updated in the attached file is the official (final) RAI. The RAI contains proprietary information pursuant to Title 10 of the Code of Federal Regulations Section 2.390, Public inspections, exemptions, request for withholding. The proprietary information is indicated by bold text enclosed with ((double brackets)). The attached nonproprietary, redacted version of the RAI will be placed in ADAMS as a publicly available official agency record.

The proprietary version of the file will be transmitted via the NRC BOX Enterprise File Sync and Share (EFSS) application.

Please contact me if you have any questions concerning this request.

Richard V. Guzman Senior Project Manager Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Office: O-9C7 l Phone: (301) 415-1030 Richard.Guzman@nrc.gov

OFFICIAL USE ONLY - PROPRIETARY INFORMATION

REQUEST FOR ADDITIONAL INFORMATION REGARDING

LICENSE AMENDMENT REQUEST

TO REVISE TECHNICAL SPECIFICATIONS FOR REACTOR CORE SAFETY LIMITS,

FUEL ASSEMBLIES, AND CORE OPERATING LIMITS REPORT

RELATED TO FRAMATOME GAIA FUEL

MILLSTONE POWER STATION, UNIT NO. 3

DOCKET NO. 50-423

EPID L-2023-LLA -0074

By letter dated May 23, 2023 (ADAMS Accession No. ML23145A195), Dominion Energy Nuclear Connecticut, Inc. (the licensee) submitted a license amendment request (LAR) to revise the technical specifications (TSs) for Millstone Power Station, Unit No. 3 (MPS3). The LAR proposes to revise the MPS3 TSs to support the use of Framatome GAIA fuel with M5' fuel cladding material, which is currently scheduled for insertion into the MPS3 reactor during the spring 2025 refueling outage. The proposed TS changes include updating the reactor core safety limits (TS 2.1.1.2), fuel assemblies design features (TS 5.3.1), and list of approved methodologies for the Core Operating Limits Report (TS 6.9.1.6.b). The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information provided in the submittal and has determined that additional information as requested in the below is needed to complete its review.

The proprietary information in this document is marked in bold font with double brackets such as

((Example)).

Regulatory Basis

The regulatory requirements and/or guidance documents associated with this LAR include the following:

(1) safety limits, limiting safety systems settings, and limiting control settings; (2) limiti ng conditions for operation, (3) surveillance requirements; (4) design features; and (5) administrative controls. This LAR, including supporting evaluations in Attachm ent 3 and 4 thereto, describes the manner in which the licensee would seek to ensure that 10 CFR 50.36 requirements continue to be met through the specification of appropriate safety limits, limiting conditions for operation, design feature descriptions, and establishme nt of administrative controls.

  • NRC Generic Letter (GL) 88-16 Generic Letter 88-16 states that it is acceptable for licensees to control core operatin g limits by specifying an NRC-approved calculation methodology. These parameter limits may be removed from the TS and placed in a core operating limits report (COLR), w hich is required to be submitted to the NRC every operating cycle or each time it is revis ed.

TS 6.9.1.6.b identifies the NRC-approved analytical methodologies that are us ed to determine the core operating limits for MPS3.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION

SRP Section 4.2 (Fuel System Design) describes acceptance criteria for preventing or limiting fuel damage. SRP Section 4.3 (Nuclear Design) establishes criteria for core power distributions, reactivity coefficients, and reactivity control requirements. SRP Section 4.4 (Thermal and Hydraulic Design) provides thermal -hydraulic criteria for th e core and reactor coolant system.

SRP Section 4.2 requires a fuel system safety review to provide assurance that (1) the fuel system is not damaged as a result of normal operation and antici pated operational occurrences (AOOs), (2) fuel system damage is never so severe as to prevent control rod insertion when it is required, (3) the number of fuel rod failures is not underestimated for postulated accidents, and (4) coolability is always maintained.

GDC 10 establishes specified acceptable fuel design limits (SAFDLs) that should not be exceeded during any condition of normal operation, including the effects of AOOs.

SAFDLs are established to ensure fuel is not damaged (i.e., fuel rods do not fail, fuel system dimensions remain within operational tolerances, and functional capabilities are not reduced below those assumed in the safety analysis) for these operating conditions.

Therefore, compliance with GDC 10 provides assurance that the integrity of the fuel and cladding will be maintained, thus preventing the potential for release of fission products during normal operation or AOOs.

Request for Additional Information

RAI-1

In Attachment 3, ANP-4040P, Revision 0, Millstone Unit 3 Mechanical Design Report for GAIA Fuel Transition, Licensing Report (Proprietary), Page 4-4, Table 4-1, Fuel Assembly Drop Accident, and Page 5-21, Section 5.1.7.3, Fuel Assembly Drop Accident Results, the licensee describes methods and results for fuel assembly drop accidents in containment and in the spent fuel pool.

a. Table 4-1 of ANP -4040P does not provide a reference for the methodology used for analyzing a fuel handling accident. Please describe any changes in the analytical approach for this event, relative to the information provided in Section 15.7.4 and Tabl e 15.7-8 of Revision 30 of the MPS3 Updated Final Safety Analysis Report (UFSAR),

which the NRC staff consulted during its review. Please further provide technical justification for any changes to the existing licensing-basis methodology.

b. Section 5.1.7.3 of ANP-4040P identifies that the number of fuel rod failures predicted for a fuel handling accident in containment [

)). This result differs significantly from the identical results described for these two fuel handling accident scenarios in Section 15.7.4 and Table 15.7-8 of Revision 30 of the MPS3 UFSAR. Please explain the reason for the significant change in the calculated results for the fuel handling accident in containment and provide adequate technical basis.

OFFICIAL USE ONLY - PROPRIETARY INFORMATION OFFICIAL USE ONLY - PROPRIETARY INFORMATION

RAI-2

, ANP-4040P, Revision 0, Millstone Unit 3 Mechanical Design Report for GAIA Fuel Transition, Licensing Report (Proprietary), Table 4-11, Limitation and Condition (L&C) 2 states, If there are changes involving the power peaking maps or other input parameters for the response surface applications, the core protection analysis should be submitted for review.

Please clarify the manner in which the licensee envisions complying with this limitation and condition for the first operating cycle with GAIA fuel. Are there any events for which DNB is predicted for which the BAW-10183 methodology would be applied, and if so, are the envisioned MPS3 core designs bounded by the power peaking maps and other input parameters discussed in the NRC staff's accompanying safety evaluation?

RAI-3

Regarding Attachment 3, ANP-4040P, Revision 0, Millstone Unit 3 Mechanical Design Report for GAIA Fuel Transition, Licensing Report (Proprietary), Page 4-22, Table 4-14, please explain the basis for the conclusion that L&C 1 is satisfied. In particular, unlike L&C 2 in the same table, there is no explicit exclusion stated in L&C 1 for components for which buckling establishes the load limit. Furthermore, considering that ((

], it is not clear to the staff that an exclusion for all buckling-limited components was intended. Please provide an acceptable technical basis that L&C 1, parts b. and c. are satisfied or not applicable.

RAI-4

Regarding the (( )) in Section 5.1.6.3.2.1 of ANP-4040, please provide additional information concerning the acceptability of this outcome, particularly:

a. Clarification [

)) (e.g.,

as compared to the uniform plastic deformation limits established in the ANP -10337 methodology for peripheral fuel assemblies).

b. A more detailed basis for ((

)).

c. Discussion concerning whether any ((

)).

d. Please clarify whether the proposed LAR is [

)).

OFFICIAL USE ONLY - PROPRIETARY INFORMATION From: Richard Guzman < Richard.Guzman@nrc.gov>

Sent: October 20, 2023 11:01:06 AM To: Shayan Sinha (Services - 6) < Shayan.Sinha@dominionenergy.com>

Subject:

Millstone Unit 3 - DRAFT Request for Additional Information Re: LAR to Revise TSs for Reactor Core Safety Limits, Fuel Assemblies and COLR related to Framatome GAIA Fuel (EPID: L-2023-LLA-0074)

Shayan,

By letter dated May 23, 2023 (ADAMS Accession No. ML23145A195), Dominion Energy Nuclear Connecticut, Inc. (the licensee) submitted a license amendment request (LAR) to revise the technical specifications (TSs) for Millstone Power Station, Unit No. 3 (Millstone 3). The LAR proposes to revise the Millstone 3 TSs to support the use of Framatome GAIA fuel with M5' fuel cladding material, which is currently scheduled for insertion into the Millstone 3 reactor during the spring 2025 refueling outage. The proposed TS changes include updating the reactor core safety limits (TS 2.1.1.2), fuel assemblies design features (TS 5.3.1), and list of approved methodologies for the Core Operating Limits Report (TS 6.9.1.6.b).

The NRC staff has determined that additional information is needed to complete its review, as described in the request for additional information (RAI) shown in the attached file. The RAI contains proprietary information pursuant to Title 10 of the Code of Federal Regulations Section 2.390, Public inspections, exemptions, request for withholding. The proprietary information is indicated by bold text enclosed with ((double brackets)). A nonproprietary, redacted version of the RAI will be placed in ADAMS as a publicly available official agency record.

The RAI is identified as DRAFT at this time to confirm your understanding of the information needed by the NRC staff to complete its evaluation. If youd like to have a clarification call, please let me know and I will coordinate availabilities w/the NRC technical staff. I intend to issue the formal questions as official by November 1st.

Thank you,

~~~~~~~~~~~~

Rich Guzman Sr. PM, Division Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Office: O-9C7 l Phone: (301) 415-1030 Richard.Guzman@nrc.gov

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