ML24023A604

Comment (011) from Jennifer Uhle on Behalf of the Nuclear Energy Institute on PR-50, 51, and 71 - Increased Enrichment of Conventional and Accident Tolerant Fuel Designs for Light-Water Reactors

ML24023A604
Person / Time
Site:	Nuclear Energy Institute
Issue date:	01/22/2024
From:	Uhle J Nuclear Energy Institute
To:	NRC/SECY/RAS
References
NRC-2020-0034, 88FR61986 00011, 88FR76143 00011
Download: ML24023A604 (1)

Text

1/23/24, 2:37 PM blob:https://www.fdms.gov/c78dca98-22d2-49d4-9626-795de3b496da As of: 1/23/24, 2:37 PM Received: January 22, 2024 PUBLIC SUBMISSION Status: Pending_Post Tracking No. lrp-l93o-3afz Comments Due: January 22, 2024 Submission Type: Web Docket: NRC-2020-0034 Increased Enrichment of Conventional and Accident Tolerant Fuel Designs for Light-Water Reactors Comment On: NRC-2020-0034-0005 Increased Enrichment of Conventional and Accident Tolerant Fuel Designs for Light-Water Reactors Document: NRC-2020-0034-DRAFT-0019 Comment on FR Doc # 2023-19452 Submitter Information Email: atb@nei.org Organization: Nuclear Energy Institute General Comment See attached file(s)

Attachments 01-22-24_NRC_Industry Comments IE Rulemaking blob:https://www.fdms.gov/c78dca98-22d2-49d4-9626-795de3b496da 1/1

Dr. Jennifer Uhle Phone: 202.247.5717 Vice President Email: jlu@nei.org January 22, 2024 Secretary, U.S. Nuclear Regulatory Commission ATTN: Rulemakings and Adjudications Staff Washington, D.C. 20555-0001

Subject:

Consolidated Industry Comments on the Nuclear Regulatory Commissions (NRC) Regulatory Basis for the Rulemaking to Amend NRCs Regulations Related to the Use of Conventional and Accident Tolerant Light-Water Reactor Fuel Designs with Greater than 5.0 and Less than 20.0 Weight Percent Uranium-235 (Docket ID: NRC-2020-0034)

Submitted via Regulations.gov Project Number: 689 The Nuclear Energy Institute (NEI) 1, on behalf of its members, appreciates the opportunity to provide the information requested by the agency related to the NRCs subject regulatory basis. The Increased Enrichment (IE) rulemaking is of high importance to the industry as utilities seek approval of higher fuel burnups and increased enrichment to extend refueling cycles. The industry applauds the NRCs initiative to address the entirety of the regulatory changes that would be needed to enable increased enrichment beyond the current 5 weight percent U-235 enrichment limit but less than 20 weight percent U-235 and higher burnup. The published IE regulatory basis is well thought out and considers the impact to 10 CFR Parts 50, 51 and 71. We believe all current regulations that would need to be modified to enable the industry to meet its strategic goals have been identified. Specific regulations to address are 10 CFR 50.67 (accident source term), 50.68 (criticality accident requirements), 51.51(b) (uranium fuel cycle environmental dataTable S-3), 51.52 (Environmental effects of transportation of fuel and wasteTable S-4), and 71.55 (general requirements for fissile material packages). To support these changes, NRC recently published Draft NUREG-2266, Environmental Evaluation of Accident Tolerant Fuels with Increased Enrichment and Higher Burnup Levels, which demonstrated the minimal environmental impact for the existing light-water reactor fleet to move beyond the current regulatory limit up to 8 weight percent U-235 enrichments and 80 GWd/MTU burnups.

1 The Nuclear Energy Institute (NEI) is responsible for establishing unified policy on behalf of its members relating to matters affecting the nuclear energy industry, including the regulatory aspects of generic operational and technical issues. NEIs members include entities licensed to operate commercial nuclear power plants in the United States, nuclear plant designers, major architect and engineering firms, fuel cycle facilities, nuclear materials licensees, and other organizations involved in the nuclear energy industry.

Rulemakings and Adjudications Staff Nuclear Energy Institute January 22, 2024 Page 2 To support the development of a clear, efficient, and durable rule, the industry responses to the NRCs general and specific questions to this IE rulemaking regulatory basis provides the industrys perspectives on the potential pathways to address source term, FFRD, and transportation packaging. The industry comments promote the completion of the IE rulemaking by 2026 to meet the goals strategic aspirationsl strategic aspirationsa strategic aspirationso strategic aspirationsof the existing light-water-reactor fleet.

Specifically, the industry goals are to safely and economically enable 24-month cycle operation for the entire fleet of existing light-water reactors by achieving the regulatory infrastructure to support burnup and enrichment extensions beyond legacy limits by 2027.

When considering these tangible benefits, the industry urges the NRC to adopt a modified Alternative 5 as the basis for the IE rulemaking, concurrent with a modified Alternative 4, if feasible. Modified Alternative 5 is the conceptually mature and preferred industry option for pressurized water reactors (PWR) to address FFRD by the 2026 completion schedule of the IE rulemaking. Industrys proposed modified Alternative 5 follows the Electric Power Research Institute (EPRI) developed Alternative Licensing Strategy (ALS) which is discussed in detail in the attachment. If the NRC determines that the EPRI ALS topical report approach from the modified Alternative 5 is applicable to only plants approved for leak-before-break, then we recommend adopting modified Alternative 4 so long as the rulemaking completion schedule is not extended significantly.

As stated in the NEI letter to Andrea Veil 2, dated March 31, 2023, NEI recommended Alternative 2 combined with a revised 10 CFR 50.46c rule to yield a modernized and risk-informed Emergency Core Coolant System (ECCS) rule while also addressing performance-based cladding behavior. The combined rule would enable more realistic operational margins and additional power uprates as incentivized in the Inflation Reduction Act. NRC staff indicated the schedule impact for Alternative 2 to be more significant than Alternatives 4 and 5. To ensure the most effective use of our collective resources, the industry recommends Alternative 2 combined with a revised 10 CFR 50.46c rule be considered in an independent rulemaking, separate and apart from this IE rulemaking. The industry remains interested in a modernized version of the draft final rule that the NRC staff submitted to the Commission in SECY-10-0161, Risk-informed Changes to Loss-of-Coolant Accident (LOCA) Technical Requirements, the so-called 10 CFR 50.46a rulemaking. Updating the previously developed rule is considered more complex than this IE rulemaking so it would delay the IE rulemaking and jeopardize the timely transition to accident tolerant fuel concepts with increased enrichment which together would enable higher burnup and improved fuel utilization. Additionally, modernizing the previously developed 10 CFR 50.46a rule would benefit from insights gained during the IE rulemaking activities. Industry affirms its interest in the large-break LOCA modernization program described in the NEI letter dated March 31, 2023; but strongly believes it should remain uncoupled from the IE regulatory improvements.

The detailed industry comments associated with the rulemaking are attached and were developed in collaboration with the PWR Owners Group, BWR Owners Group, Westinghouse, Framatome, Global 2 ML23107A230

Rulemakings and Adjudications Staff Nuclear Energy Institute January 22, 2024 Page 3 Nuclear Fuels - Americas, Orano, Urenco, World Nuclear Transport Institute, and other industry organizations. Specific responses from these organizations provide complementary technical details that expand upon industrys consensus positions provided herein.

If you have any questions, please contact me or Dr. Aladar Csontos at aac@nei.org or (202) 557-9727.

Sincerely, Jennifer Uhle Vice President Attachment cc: Andrea Veil, Director, NRR, NRC Joe Donoghue, NRR, NRC Michael Franovich, NRR, NRC Andrea Kock, NRR, NRC Bo Pham, NRR, NRC Shana Helton, NMSS, NRC

Attachment:

Industry Comments General Questions:

The NRC is requesting comments on the regulatory basis. As you prepare your comments, consider the following general questions:

1. Is the NRC considering appropriate options for each regulatory area described in the regulatory basis? Please provide a basis for your response.

Industry Response:

NRC has considered a wide array of options for each of the regulatory areas in the regulatory basis. It is commendable that NRC considered some innovative approaches that could substantially reduce the regulatory burden associated with FFRD through the use of risk insights. These approaches should be evaluated more thoroughly to determine their viability to meeting the current 2026 completion schedule for the IE Rulemaking.

2. Are there additional factors that the NRC should consider in each regulatory area? What are these factors? Please provide a basis for your response.

See the Industry Responses to the Specific Questions

3. Are there any additional options that the NRC should consider during development of the proposed rule? Please provide a basis for your response.

See the Industry Responses to the Specific Questions

4. Is there additional information concerning regulatory impacts that the NRC should include in its regulatory analysis for this rulemaking? Please provide a basis for your response.

See the Industry Responses to the Specific Questions

5. Discuss whether the proposed rule would present hardships to regulated small entities. How could rule provisions be modified to lessen these impacts? Please provide a basis for your response.

The proposed alternatives in the IE rulemaking regulatory basis are numerous with varied potential impacts. At this stage, the uncertainty is too large to determine the future hardships on regulated small entities.

6. What opportunities are there to increase the beneficial impacts of the rule on small entities?

Please provide a basis for your response.

The proposed alternatives in the IE rulemaking regulatory basis are numerous with varied potential impacts. At this stage, the uncertainty is too large to determine the opportunities to increase the benefits of the rule for small entities.

1

Attachment Page 2 Specific Regulatory Issues In addition to the general questions, the NRC is requesting specific feedback from the public and has prepared specific questions related to control room design criteria; transportation of uranium hexafluoride and FFRD.

Control Room Design Criteria The NRC is seeking comment on the alternatives proposed in Appendix A of the regulatory basis on control room design criteria.

1. Would the numerical selection of the control room design criteria be better aligned with regulations designed to limit occupational exposures during emergency conditions (e.g.,

§§ 20.1206, Planned special exposures, and 50.54(x)) or regulations designed to limit annual occupational radiation exposures during normal operations (e.g., § 20.1201, Occupational dose limits for adults, specifically the requirements in § 20.1201 (a)(1)(i))? Please provide a basis for your response.

Industry Response:

The intent of maintaining a habitable control room is to ensure that operators can respond in the unlikely event of an accident. Considering the importance of control room habitability, the selection of updated values for control room design criterion should be more aligned with the various U.S. and international organizations recommendations for emergency dose limitations up to 25 rem total equivalent dose equivalent (TEDE). As described in the regulatory basis document, the control room design criteria are not intended to be operational limits and should not be used to imply what is an acceptable exposure during emergency conditions. However, they are used to demonstrate that a plant design is adequate to maintain a habitable control room during highly unlikely, hypothetical events up to and including the maximum hypothetical accident (MHA). The MHA is an event which results in substantial meltdown of the reactor core with subsequent released of appreciable quantities of fission products.

Compliance with the control room design criterion is currently shown through deterministic radiological consequence analyses with a set of inputs and assumptions that bound what might be seen in an actual event (occupancy factors, breathing rates, filter efficiencies, flow rates, atmospheric dispersion, no potassium iodine (KI) or respiratory protection, etc.). Considering the low probability of occurrence of an accident and the conservative assumptions made as part of these analyses, a graded, risk-informed method for compliance with control room design criteria up to 25 rem TEDE is appropriate and would provide the necessary flexibility for current and future technologies.

Additional information to support the basis for a control room design criteria up to 25 rem TEDE is provided in response to question #2.

2. Would a graded, risk-informed method, to demonstrate compliance with a range of acceptable control room design criterion values instead of a single selected value such as the current 5 rem (50 millisievert(mSv)) total effective dose equivalent (TEDE) provide the necessary flexibilities for current and future nuclear technologies up to but less than 20.0 weight percent U-235 enrichment? Please provide a basis for your response.

Industry Response:

Attachment Page 3 A graded, risk-informed approach within a range of acceptable control room design criterion values would provide the necessary flexibility for current and future technologies. A range of 10 to 25 rem TEDE would provide an acceptable level of control room habitability necessary to provide reasonable assurance that the control room would continue to be effectively staffed and operated to mitigate the effects of the accident and protect public health and safety. The upper limit of 25 rem TEDE should be included in GDC 19 in Appendix A to 10 CFR Part 50 and 10 CFR 50.67, with potential to reduce criterion values down to 10 rem TEDE for certain accident scenarios based on the accident likelihood. Criteria for these potentially reduced criterion values could be specified in regulatory guidance.

Basis for Response:

A risk-informed range for control room design criterion is consistent with the current practice for offsite dose and the approach proposed for advanced reactors in NEI 18-04, Revision 1, Risk-Informed Performance-Based Technology Inclusive Guidance for Non-Light Water Reactor Licensing Basis Development. This approach would not unnecessarily penalize licensees for seeking increased enrichments that may then result in margin reductions and thereby require licensees to perform potentially dose-intensive plant modifications or maintenance, or perform extensive radiological safety analyses, to demonstrate compliance without a commensurate increase in safety.

The value of 10 rem TEDE represents a lower bound and is based on substantial scientific data that shows the observed radiation effects in individuals are not statistically different from zero, as noted in Health Physics Society Position Statement PS010-4, Radiation Risk in Perspective. 1 In addition, currently, under 10 CFR Part 20, workers can receive up to 10 rem (100 mSv) TEDE occupationally during a 12-month period or, under a special circumstance, within a calendar year.

The value of 25 rem TEDE represents the upper bound and is based on various U.S. and international organizations recommendations (e.g., EPA PAG Manual) for emergency dose limitations up to 25 rem TEDE and the recognition that the GDC 19 and dose-based criteria specified in 10 CFR 50.67(b)(2) are design criteria, not operational limits. While the design criteria are computed in terms of dose, they are figures of merit used to characterize the minimum necessary design, fabrication, construction, testing, and performance of the requirements for systems, structures, and components (SSCs) that are important to safety. The design basis accident (DBA) conditions assumed in these analyses, although credible, generally do not represent actual accident sequences but are specified as conservative surrogates to create bounding conditions for assessing the acceptability of engineered safety features. The design criteria do not represent actual or expected occupational exposures received during normal and emergency conditions. Under this proposal, this upper limit of 25 rem TEDE should be contained in GDC 19 in Appendix A to 10 CFR Part 50 and 10 CFR 50.67 and provide a criterion that is also consistent with the current offsite limit of 25 rem TEDE in 10 CFR 50.67. As stated in 61 FR 65157 regarding reactor siting criteria, this offsite limit corresponds numerically to the once in a lifetime accidental or emergency dose to radiation workers which could be disregarded in the determination of their radiation exposure status. In addition, control room operators are generally composed of individuals expected to be less sensitive to any adverse effects of radiation relative to members of the public.

1 https://hps.org/documents/radiationrisk.pdf

Attachment Page 4 The specific control room design criterion value for each accident should be based on a risk-informed approach as currently applied for the offsite dose design criteria. The upper bound of 25 rem TEDE for the control room design criteria should apply to accidents whose sequence frequency would classify them as beyond-design-basis or severe accidents. These events include the Maximum Hypothetical Accident, which involves multiple failures of redundant trains of safety systems and results in potential hazards not exceeded by those from any accident considered credible with substantial meltdown of the core with subsequent release of appreciable quantities of fission products. For events with higher sequence frequencies, the lower limit of 10 rem TEDE for the control room design criterion should apply to ensure the risk to the operators is not increased. -

Example for a generic graph for the control room design criteria:

Conditions for the use of these values may be specified in regulatory guidance. Near-term guidance updates should also incorporate modeling improvements to allow the use of best-estimate solutions and credit removal phenomena such as suppression pool scrubbing and condenser plate-out. These modeling improvements would apply to deterministic, best-estimate methods which incorporate statistical selections of inputs and assumptions. Deterministic best estimate applications combined with accurate uncertainty quantification result in more accurate margin determination but would still include conservatism.

Attachment Page 5 Transportation of Uranium Hexafluoride The NRC is seeking comment on the alternatives proposed in Appendix E of the regulatory basis on fissile material package requirements. To date, industry plans communicated to the NRC have not indicated that there will be enough requests for package approvals for transporting UF6 enriched up to but less than 20.0 weight percent U-235 to conclude that rulemaking would be the most efficient or effective process to support package approvals. Further, all alternatives to rulemaking that the NRC considered are nearly cost neutral in terms of implementation; however, rulemaking shifts the cost burdens to the NRC disproportionally when compared to taking no rulemaking action.

1. Is there additional information that can be shared to augment comments made by the public in June 2022 regarding the need for rulemaking to support licensing new or existing UF6 transportation package designs?

Industry Response:

NRC has proposed three alternatives for consideration and analysis regarding the need for rulemaking to support licensing new or existing UF6 transportation package designs. The alternatives include retaining the original basis for regulation, rulemaking to allow an increased enrichment limit up to, but less than 20.0 weight percent U-235 and rulemaking to remove the enrichment of 5.0 weight percent U-235. The second and third alternatives also suggest that updates to the guidance in NUREG-2216 may be necessary.

As noted in Appendix E, NRC staff recommends no regulatory action. The staff recommendation is based on a staff assessment of the industry plans communicated to the NRC in June 2022. Industry holds that any uncertainty or lack of specific knowledge regarding the number of future package approval requests does not suggest there will be an insufficient number of requests for package approvals for transporting UF6 enriched up to but less than 20.0 weight percent U-235 to justify not undertaking rulemaking and recommending the no action alternative.

The recommendation of Alternative 1 based on current uncertainty does not position industry or NRC to efficiently prepare or review transportation package designs. While Alternative 1 is the least resource-intensive option at present, it establishes a regulatory framework for rulemaking by exemption which is inconsistent with NRCs Principles of Good Regulation. Selection of the no action alternative does not support long-term regulatory efficiency, nor does it enable an efficient market for utilizing and transporting highly enriched fuel products, including highly enriched uranium (HEU), uranium hexafluoride (UF6) as well as enriched material up to but less than 20% (LEU+, HALEU.)

The lack of incremental impacts to NRC and stakeholders under Alternative 1 is valid only in the near-term, consistent with near-term understanding of transportation needs. The impacts of regulation by exemption would far outweigh near-term savings as the need for and volume of transportation of highly enriched products increases over time, thus undermining the basis for the NRC staffs recommending no action now and imposing unnecessary added future burdens for eventual rulemaking and concurrent exemption activities.

Industry urges NRC to increase the 5.0% by weight enrichment limit in its regulatory framework and recommends pursuing Alternative 2, thus allowing for use of Part 71 for highly enriched products including highly enriched uranium (HEU), UF6 as well as enriched material up to 20%

Attachment Page 6 (LEU+, HALEU.). We recognize that any regulation has the potential for conflict with the Department of Transportation (DOT) and International Atomic Energy Agency (IAEA) regulations (SSR-6). There is no prohibition for NRC to approve package designs outside of DOT and/or IAEA regulations as demonstrated by existing NRC approvals:

• Westinghouse Traveller 71-9380 package to transport fresh uranium or slightly contaminated uranium fuel assemblies with enrichments up to 6.0 weight percent U-235 or rods with enrichment up to 7.0 weight percent U-235 (ML23024A176)

• Westinghouse Traveller 71-9297 package to transport fresh uranium fuel assemblies with enrichment up to 5.0 weight percent or rods with enrichments up to 7.0 weight percent U-235 (ML20269A339)

• Global Nuclear Fuel - Americas RAJ-II package to transport fresh uranium fuel assemblies up to 8.0 weight percent U-235 enrichments (ML23199A313)

• Framatome MAP-12 and MAP-13 packages to transport fresh uranium fuel assemblies with enrichments up to 8.0 weight percent U-235 (ML21343A230)

• Orano NCS DN30-X transportation package to transport UF6 with enrichments up to 20.0 weight percent U-235 (ML23083B978)

• NAC certificate of compliance No. 9390 Rev. 2 package enabling transport of greater than 5 weight percent U-235 of TRISO HALEU in quantities greater than 500 lbs.

Any additional permitting needed should not preclude the benefits of a durable regulatory framework for Part 71 transportation packages.

Fuel Fragmentation, Relocation, and Dispersal The NRC staff has identified that additional feedback from stakeholders would be beneficial before making a final recommendation on rulemaking on FFRD. The NRC is seeking comment on the alternatives proposed in Appendix F of the regulatory basis on FFRD.

1. Are there any other alternatives not described in Appendix F of the regulatory basis on FFRD that the NRC should consider? Are there elements of the alternatives presented or other alternatives that the NRC should consider? Please provide a basis for your response.

Overarching Industry Response:

The industry urges the NRC to adopt a modified Alternative 5 concurrent with a modified Alternative 4 as the bases for the IE rulemaking, if feasible. Modified Alternative 5 is the highly mature and preferred industry option for PWRs to address FFRD by the 2026 completion schedule of the IE Rulemaking.

This would support the industrys strategic goals to enable 24-month cycle operation safely and economically for the entire fleet of existing light-water reactors by achieving the regulatory infrastructure to support burnup and enrichment extensions beyond legacy limits by 2027.If the NRC determines that the EPRI ALS topical report approach from the modified Alternative 5 is applicable to only plants approved for leak-before-break, then we recommend adopting modified Alternative 4 so long as the rulemaking completion schedule is not extended significantly.

Attachment Page 7 Additionally, the rulemaking discussed in appendix F, noted the need to clarify, by policy or other regulatory pathways, the applicability of 10 CFR 50.46 coolability requirements to dispersal - regardless of the Alternative selected. The discussion implied that, contrary to previous NRC regulatory evaluations, any fuel dispersal may be prohibited by existing regulations. This perspective is not proportional to the potential safety consequences. While the industry agrees that clarity is an important attribute to regulation, regulations should also reflect the risk significance of the underlying phenomena.

As stated in the NEI Letter to Andrea Veil dated March 31, 2023 2, NEI recommended Alternative 2 combined with a revised 50.46c rule to yield a modernized and risk-informed ECCS rule that would also improve operational margins and permit additional power uprates as incentivized in the Inflation Reduction Act. NRC indicated the potential schedule impact to be more significant than Modified Alternatives 5 and 4. To ensure the most effective use of our collective resources, industry recommends Alternative 2 combined with a revised 50.46c rule be considered in a follow-on independent rulemaking subsequent and apart from these IE rulemaking activities.

The industry remains interested in a modernized version of the draft final rule that the NRC staff submitted to the Commission in SECY-10-0161, Risk-informed Changes to Loss-of-Coolant Accident (LOCA) Technical Requirements, - the so-called 10 CFR 50.46a rulemaking. Updating the previously developed rule is considered more complex than this IE rulemaking. Industry believes such an approach would delay the IE rulemaking and jeopardize the timely transition to accident tolerant fuel concepts with increased enrichment enabling higher burnup and fuel utilization. Additionally, modernizing the previously developed 10 CFR 50.46a rule would benefit from insights gained during the IE rulemaking activities. The industry affirms its interest in the large-break LOCA (LBLOCA) modernization program described in the NEI letter dated March 31, 2023; but strongly believes it should remain uncoupled from the IE regulatory improvements.

Specific Responses to Modified Alternative 5:

NRC postulated several alternative options in the IE rulemaking regulatory basis. NRCs Alternative 5 is a variation on the Electric Power Research Institute (EPRI) developed Alternative Licensing Strategy (ALS), previously discussed with the NRC at two pre-submittal meetings 34. The primary difference between ALS and the NRC proposed Alternative 5 is the regulatory treatment of LBLOCA. ALS applies leak-before-break (LBB) concepts and risk insights developed from probabilistic piping fracture mechanics to LBLOCA-induced FFRD but not to other LOCA phenomena. Alternative 5 goes a step further by allowing the use of these LBB results to reclassify LBLOCA as a non-credible event and eliminate the need to address all LBLOCA phenomena. As proposed by NRC, Alternative 5 would have a negative impact on the IE rulemaking schedule and cost.

Therefore, the industry proposes a modified Alternative 5 that limits the scope to allow LBB, with supporting probabilistic fracture mechanics results, to only address LOCA induced FFRD. By doing so, the schedule and costs associated with this modified Alternative 5 would not negatively impact the current schedule of the IE rulemaking.

As described in the assessment of Alternative 5, the NRC proposed various regulatory pathways to incorporate the use of LBB into ECCS evaluations. Options discussed include revising the existing LBB policy to clarify its applicability to fuel dispersal, revisions to GDC 4, revision to 10 CFR 50.46 or a combination of the above. The industry encourages the 2

ML23107A230 3

NRC/EPRI Public Meeting on 8/30/22 (ML22236A560, ML22236A562, ML23312A005) 4 NRC/EPRI Public Meeting on 11/8/23 (ML232299A247)

Attachment Page 8 NRC to select the most expeditious path while meeting the goals of regulatory clarity, predictability and durability.

The NRC proposes that exemption requests could be used to implement Alternative 5 while rulemaking is progressing. This approach does not provide the regulatory clarity needed for efficient NRC and industry engagements. A commitment to a firm rulemaking schedule, including dispersal effects, that supports the industry implementation schedule, is preferred by the industry and is more effective.

The proposed IE rulemaking with FFRD considerations assumes that all alternatives would support a transition to increased enrichment and a corresponding adoption of higher burnup over an 8-year period. This is a reasonable assumption for modified Alternatives 4 and 5 but less reasonable for the other alternatives. Additional research, development and regulatory interactions are required for all other alternatives, to a varying degree. This would delay the implementation of increased enrichments and higher burnup resulting in a net reduction in the safety, operational, and economic benefits derived thereof. The extent of the delay is estimated to range between 3 and 10 years depending on the alternative. Based on results published in NEI White Paper, The Economic Benefits and Challenges with Utilizing Increased Enrichment and Fuel Burnup for Light-Water Reactors, 5 (Table 8 line 6 - line 5),

a delay in achieving high burnup of 5 years would reduce the fuel cost benefits by $687M.

Higher burnup will reduce the number of discharged fuel assemblies (~4000 assemblies) and therefore reduce the production of high-level waste (HLW). While results would be expected to vary on by site, these results provide a relative figure of merit. Alternative 4 is expected to result in a smaller impact while Alternatives 2 or 3 would have larger impact.

This delay would also impact the transition to 24-month fuel cycles (MFC) for many PWR reactors and result in the following safety impacts:

A) Reduced occupational dose due to fewer refueling outages (18MFC vs. 24MFC) and dry cask campaigns.

B) Reduced radiological impact on the public due to lower site boundary dose levels, resulting from fewer dry casks and the eventual transportation of HLW to a repository.

C) Reduced risk of fuel transportation related events for both the front end and back end of the fuel cycle.

D) Increased fuel design efficiency reduces the environmental impact of mining, milling and fuel fabrication.

E) Reduced industry and NRC resources needed to develop and apply dispersal models, allowing application of scarce resources to more safety significant tasks.

F) Improved economic performance for plants, reducing the risks of early plant shutdowns, supporting US and international environmental goals for reduced greenhouse emissions.

The following additional specific comments to the proposed Alternative 5 are provided:

5 NEI White Paper, The Economic Benefits and Challenges with Utilizing Increased Enrichment and Fuel Burnup for Light-Water Reactors, February 2019. https://www.nei.org/resources/reports-briefs/economic-benefits-and-challenges-increased-enrich

Attachment Page 9

• As described, the proposed rulemaking notes that plant specific analysis will be needed to demonstrate that the time available to detect leakage that predates LBLOCA and shut down the reactor is sufficient to prevent pipe rupture. All plants that adopt ALS would already have LBB approval for the relevant piping systems.

The xLPR probabilistic fracture mechanics analyses used to support the time available to shutdown the plant is broadly applicable to the PWR fleet, and a site-specific analysis is not anticipated to be necessary. A site-specific confirmation that the xLPR analysis applies to the site specific design features is considered sufficient.

Likewise, the overall ALS conclusions are applicable to plants that meet specific ECCS and other design assumptions. Plant specific validation of the applicability of these assumptions is considered sufficient to confirm the applicability of the ALS conclusions. Plants that fall outside of these design assumptions could optionally perform a plant specific analysis.

• The NRC proposed alternatives are assumed to require 8 years to complete the licensing and fuel transition starting as early as 2022 to completion by 2030.

Alternative 5 potentially supports that 8-year timeframe but the NRC has not published the rulemaking schedule accounting for dispersal activities. The industry believes there are significant schedule impacts due to the implementation and/or potential research requirements of the NRC proposed alternatives. As discussed above, this results in significant cost impacts that are not included in the NRC economic evaluation. Prompt rulemaking, including dispersal effects for Alternative 5, avoids these impacts on the industry and supports the safety benefits described above.

• Alternative 5 takes the EPRI ALS logic one step further by applying the piping fracture mechanics risk insights to categorize LBLOCA as an incredible event and obviate the need to analyze LBLOCA events. The proposed ALS approach would limit the application of the fracture mechanics risk insights to FFRD effects and retain the existing regulatory framework to address other 50.46 acceptance criteria. The extension is expected to add complexity to the rulemaking which is likely to have a negative impact on both cost and schedule. The industry proposes that the LBLOCA rulemaking scope be limited to FFRD effects and Alternative 5 be revised accordingly.

Specific Responses to Modified Alternative 4:

Alternative 4 would update the current regulatory framework for ECCS performance to consider fuel dispersal and allow for risk insights to be used to disposition downstream effects of fuel dispersal. NRC would need to revise 10 CFR 50.46 to treat fuel dispersal during a LOCA as a beyond-design-basis phenomenon.

As described in the IE regulatory basis, Alternative 4 would consider the downstream effects of fuel dispersal, such as criticality, coolability, and long-term cooling, as beyond-design-basis consequences that can be reasonably addressed with insights from operating experience and other regulatory requirements, programs, and industry initiatives. Under this alternative, radiological consequences of a LOCA with fuel dispersal would be addressed by showing that dose-based acceptance criteria can be met (the actual dose-based acceptance criteria would need to be developed during the rulemaking process). The staff would develop new regulatory guidance to specify applicable acceptance criteria and acceptable methods for analyzing the DBA LOCA to quantify the amount of predicted fuel dispersal.

Attachment Page 10 This new guidance would include direction on the use of a fraction of the bounding maximum hypothetical accident LOCA source term in lieu of quantifying the source term from dispersed fuel.

This alternative only requires an assessment of the dose consequences of FFRD, limiting the impact on existing LOCA methods. The desired means to assess the number of rods which disperse fuel is to use details from the core design and bounding assumptions (e.g.,

all high burnup (HBU) rods burst). Should this approach not be successful, updates to LOCA methods would be needed, however they would be limited to updates required to predict the amount of rupture and/or dispersal. The key objective of this alternative is demonstration of public health and safety. This objective is achieved via demonstrating allowable dose limits are not exceeded. After the demonstration of the main objective, this alternative considers all downstream effects of FFRD in the beyond-design-basis category, via use of risk insights. This allows stations to utilize risk insights for beyond-design-basis considerations, yet deterministically address the dose consequences.

Industrys understanding of this approach is summarized below.

1. The effects of fuel dispersal on radiological source term would be treated as part of the plants design basis. Radionuclides released from the fuel rods due to fuel dispersal, beyond those already considered as part of the gap release, would need to be accounted for in radiological consequence assessments.

2. The downstream effects of fuel dispersal, such as criticality, coolability, and long-term cooling, would be treated as part of the plants mitigating strategies for beyond-design-basis events. Based on industry improvements in the area of event mitigation through the EOP, B5B, FLEX and SAMG procedures along with the E-Plan, plants may be able to demonstrate that downstream effects of fuel dispersal do not require any further action.

a. The use of risk insights for addressing downstream effects is key for this alternative. Otherwise, this alternative turns into Alternative 3, with multi-year effort/research.

3. Since downstream effects of fuel dispersal are considered beyond-design-basis, ECCS performance would not be judged based on these downstream consequences. ECCS performance would be judged based on predictions of peak cladding temperature (10 CFR 50.46 (b)(1)), maximum cladding oxidation ((b)(2)),

maximum hydrogen generation ((b)(3)), and long-term cooling ((b)(5)), independent of any impacts on these predictions due to downstream effects of fuel dispersal.

Furthermore, coolable geometry ((b)(4)) would not be interpreted as requiring the consideration of dispersed fuel.

4. A new requirement would be added to demonstrate that impacts of fuel dispersal on radiological source term are considered in the DBA-LOCA radiological consequence assessment. Any impacts due to fuel dispersal on radiological source term are limited to HBU fuel rods susceptible to fine fragmentation. In other words, fuel dispersal is not considered for fuel rods below the burnup threshold for fine fragmentation, consistent with regulations currently in place.

5. This alternative eliminates the need to develop and implement significant additional restrictions on fuel design and core management strategies to prevent fuel dispersal beyond those needed to demonstrate that radiological consequences are satisfied.

Design basis radiological dose consequences analyses will demonstrate compliance

Attachment Page 11 with the acceptable dose limits to ensure public health and safety. The fuel design and core management strategies will need restrictions if compliance to dose consequences cannot be demonstrated.

6. Alternative 4 is applicable to all LOCA scenarios, irrespective of break size. Risk insights are incorporated via the definition of allowable radiological consequences. In other words, piping breaks of higher frequency of occurrence would be limited to a lower allowable radiological consequence, relative to less frequent breaks.

7. Alternative 4 would be combined with the ongoing initiative to revise the control room design radiological consequence criteria.

Based upon the above understanding, the industry has compiled the following comments to improve the efficiency and effectiveness of Alternative 4. With these improvements, the industry is referring to the proposal as the modified Alternative 4.

• Industry agrees that allowable radiological consequences and acceptable analytical methods should reside in regulatory guidance (e.g., RG 1.183), as opposed to a modified rule. However, this guidance needs to be completed in time to support the existing IE rulemaking schedule.

• Industry agrees that regulatory guidance is needed to incorporate crediting currently available mitigation strategies/systems, such as SAMGs, B5B, FLEX, etc., for beyond design basis downstream consequences of fuel dispersal.

o Downstream effects of fuel dispersal do not require any further action, based on industry improvements in the area of event mitigation through the EOP, B5B, FLEX and SAMG procedures along with the E-Plan.

o The use of risk insights for addressing downstream effects is key for this alternative. Otherwise, this alternative turns into Alternative 3, with multi-year effort/research.

• The allowable EAB/LPZ radiological consequences for extremely low frequency, large diameter piping breaks (i.e., LBLOCA) should be 25 rem TEDE. This allowable limit is consistent with RG 1.183, Revision 1, Table 7 accident dose criteria for DBAs with similar anticipated frequencies of occurrence (e.g, BWR MSLB, PWR MSLB, PWR SGTR).

• For events of higher frequency, the allowable EAB/LPZ radiological consequences should be based on a graduated approach consistent with RG 1.183, Revision 1, Table 7 accident dose criteria (e.g., BWR CRD, PWR CRE, FHA).

• NRC guidance should allow licensees to predict core-wide fuel dispersal using (1) simplified and conservative analytical methods or (2) detailed core-wide predictions of HBU fuel rod rupture and fuel dispersal. An example simplified solution to predict the quantity of fuel dispersal would be to assume 1 grid span of fuel is dispersed from all in-board, HBU fuel rods. HBU fuel rods along the periphery are unlikely to rupture due to significantly lower power levels in these locations. This simplified approach would not require the development of detailed, core-wide fuel rod burst models.

Attachment Page 12

• NRC guidance should allow licensees to predict the impact of dispersed fuel on the radiological source term using (1) simplified and conservative analytical methods or (2) detailed radionuclide evaluations. An example simplified solution would be to combine the core-average gap release fraction with an additional source term corresponding to fraction of core-wide HBU dispersal divided by fraction of core-wide melt from MHA-LOCA early in-vessel release.

2. Stakeholders previously expressed concerns on the proposed § 50.46a rule when it was initially proposed in 2010. What concerns about § 50.46a (i.e., Alternative 2) exist in todays landscape?

Please provide a basis for your response.

Industry Response:

The primary concern with Alternative #2 (§ 50.46a) for this IE rulemaking is schedule, as indicated in the NRC regulatory basis document. Modified Alternatives #5 and #4 provide options to address FFRD in a risk-informed manner more expeditiously for fuels licensing.

Nevertheless, a revitalized § 50.46a rule could also provide additional margins for power uprates through improved realism for LBLOCA which would aid LBLOCA limited plants.

Much time has passed since the NRC staff began developing a risk-informed approach to ECCS requirements over fifteen years ago. Since 2010, considerable advancements in Probabilistic Risk Assessment (PRA) and Probabilistic Fracture Mechanics (PFM) technologies have been made along with widespread industry adoption of risk-informed programs and peer review of PRAs using RG 1.200 PRA methods. In particular, the requirements associated with analyzing break sizes greater than the transition break size in the draft final rule were much more stringent when compared to the requirements for analysis of other beyond design basis accidents, especially considering the extremely low probability of the initiating event. The following are specific topics to address:

• The final draft rule does not align with the intent of the risk-informed rulemaking. The level of reasonable assurance should be commensurate with risk, as initially envisioned for this risk-informed rule. And a 95/95 probability/assurance level (which has been imposed on the industry) is beyond reasonable assurance for these extremely low frequency of occurrence events. The industry recommends that the evaluation model and compliance metric be established with a level of probability commensurate with risk.

In the early stages of the 50.46a risk-informed rulemaking 6, a lower level of assurance commensurate with the likelihood of occurrence was proposed for piping breaks beyond the transition break size (TBS). Hence, lower probability, larger piping breaks beyond the TBS would be allowed to demonstrate compliance in a more realistic manner. By the final draft rule (2010), the level of assurance reverted back to a high level of probability for both the more probable smaller piping breaks and breaks beyond the TBS. The final draft rule does not align with the intent of the risk-informed rulemaking.

• Industry recommends removing the requirement for the unnecessary Low Power and Shutdown Modes PRA in light of the industry advances in shutdown risk management (e.g., continuing improvements to NUMARC 91-06 defense-in-depth practices) and the 6

Risk-Informed Changes to Loss-of-Coolant Accident Technical Requirements, FRN 70 FR 67597, November 7, 2005.

Attachment Page 13 negligible risk impact of 10 CFR 50.46a implementation during these modes of operation. The industry agrees that PRA quality must be adequate to calculate the risk impact from adoption of the rule. However, the risk impact of LOCAs greater than the TBS in low power shutdown modes is negligible and therefore this requirement is unnecessary.

• Given more recent experience and knowledge, industry recommends removing the requirement for plant specific seismic analyses to demonstrate applicability of the TBS in the draft final rule, and to instead focus industry and NRC resources on demonstration of validity of PRA success criteria. NUREG-1903, Seismic Considerations for Transition Break Size, provided a technical analysis that dispositioned the need to consider the impact of seismic events on the TBS given the very small contribution to potential failure modes. The rule, however, still calls for plant-specific seismic analysis to support application of the TBS. Per NEIs March 6, 2006, letter on the topic (Attachment 4 of ML060660036), The change in risk (delta risk) relative to seismic events is estimated to be negligible based on the fact that the TBS threshold does not directly impact either the seismic hazard (the seismic hazard is the same whether the SECY-10-0161 draft final rule was established or not) or the plant SSC seismic fragilities (the fragilities are a function of the structures/equipment construction, their design, their load path, their anchorage, etc. Establishing a TBS does not alter these from a seismic fragility perspective). More recent experience, analyses, and knowledge allow for more efficient ways of confirming that the conclusions of NUREG-1903 remain valid, with an emphasis on confirmation that the existing PRA success criteria remain valid following implementation.

• Deterministic fracture mechanics and PFM technologies have advanced substantially since this policy statement was issued, and LBB applications were approved for specific piping systems. LBB has been evaluated for a number of conditions and degradation mechanisms that could lead to pipe rupture. Some of these degradation mechanisms are not applicable to piping systems above the proposed TBS. Piping systems that have been evaluated using the NRCs fracture mechanics analysis procedures support a determination that detectable leaks will occur before pipe rupture and support a determination that the probability of piping rupture is extremely low.

3. Under Alternative 2, as currently proposed in the regulatory basis, the staff would apply the regulatory precedent under which fuel dispersal that would challenge current regulatory requirements would not be permitted under loss-of-coolant accident (LOCA) conditions. Would the increased flexibilities gained from best-estimate assumptions and methods employed during large-break LOCA analyses make this alternative reasonable? Please provide a basis for your response.

Industry Response:

It was discussed in response to the prior question that the level of reasonable assurance should be commensurate with risk, and a 95/95 probability/assurance level (which has been imposed on the industry) is beyond reasonable assurance for events with low frequency of occurrence such as breaks larger than the TBS. The increased flexibilities gained from the draft final rule language included in the 10 CFR 50.46a rulemaking as written in 2010 would NOT make this

Attachment Page 14 alternative reasonable, as the benefits from those flexibilities are insignificant compared to the inherent conservatism present in licensing basis LOCA evaluation models combined with the requirement to demonstrate compliance with the regulatory criteria at 95% probability with 95%

confidence. If the rule language was updated to allow for true best-estimate analysis for breaks larger than the TBS (as opposed to a 95/95 calculation), this could be a reasonable alternative when combined with anticipated benefits that will be gained from accident tolerant fuel (ATF) products.

Ultimately, the reasonableness of this alternative for the industry cannot be assessed without more specific information regarding the nature of the intended regulatory requirements. Given the anticipated schedule impact of Alternative 2, this alternative may best be considered in combination with other (modified) alternatives, or in combination with a revised 10 CFR 50.46c via a follow-on rulemaking separate and apart from this IE rulemaking activity.

4. What changes to plant operations, fuel designs, or safety analysis tools and methods would be necessary under each proposed alternative? Please provide a basis for your response.

Industry Response:

All options require the qualification of reactor physics methods and fuel mechanical analysis methods to support the LOCA input generation at higher burnup and enrichments. Some modifications to existing fuel assembly designs may be required to demonstrate acceptable rod internal pressure, corrosion performance, rod growth and other fuel design criteria.

Alternative 3 will require the development of particle transport methods that predict the distribution of fuel particles throughout the reactor coolant system and containment. This transport modeling would consider particle mobility as a function of particle size, steam velocity and fuel grid interference. The radiological and potential fuel criticality of the determined particle distribution would need to be performed. The qualification of these methods would be expected to involve additional research similar to activities currently being performed under the CRAFT framework.

Alternative 4 would require an acceptable method to determine the particle dispersal mass. A simplified conservative approach based on fuel burnup and dispersed column height may be sufficient to demonstrate the radiological effects are bounded by the accident source term.

These responses are based in part on the NRC ATF project plan, CRAFT program scope and representative LOCA analysis input requirements. These responses address LOCA-induced FFRD and do not address other plant design issues that are outside the scope of this rulemaking.

5. Provide any information that would be relevant to more accurately estimate costs associated with each proposed alternative. Please provide a basis for your response.

Industry Response:

In addition to the NRC estimated net benefits from Alternative 5 ($17.6M), the scheduled timeline implementation of advanced fuels with higher burnup and increased enrichments from modified Alternative 5 would result in the industry saving of ~$190M in fuel costs and $78M in dry cask storage costs for a total of ~$285M (undiscounted) based on a 60-year operating life.

The other proposed alternatives in the IE Rulemaking Regulatory Basis have uncertainties with

Attachment Page 15 potential research, development, and implementation costs. These uncertainties are too large at this point to determine the financial impacts to the industry at this time. The industry will provide the more accurate cost estimates once clarity on the specifics for each alternative is fully developed.

6. What are the pros and cons of each alternative, including the degree to which each alternative is consistent with the principles of good regulation?

Industry Responses:

Alternative #1:

Pros:

• None Cons

• Does not provide additional clarity or efficiencies from the current state which is not useful and continues the regulatory uncertainties without resolution.

Alignment with Principles of Good Regulation

• Alternate #1 is incompatible with the principles of good regulation as it does not provide clarity or efficiencies for the current state.

Alternative #2:

The SECY-10-0161 draft final rule (§ 50.46a) focused on risk-informed changes to align the assumptions for LOCA analysis to the initiating event. It created different standards for break ranges below and above a transition break size (TBS), based upon the lower event probability of occurrence and risk above the TBS. That regulatory effort is consistent with the Commissions continued direction and drive towards more modern and risk-informed regulation.

Pros:

• Provides a modern, risk-informed regulation.

• Potential to improve margins to allow for power uprates.

• Reduces regulatory burden for an extremely low probability event, while being able to maintain reasonable assurance of adequate protection.

• Leverages prior rulemaking which was nearly completed.

• Maintaining the high probability requirements for breaks below the defined TBS, consistent with the current regulation for the more probable break sizes, does not affect defense in depth.

Cons:

Attachment Page 16

• May not provide improved margins for the entire fleet.

• May not be a success path for the entire fleet without some additional evaluations to address some amount of dispersal.

• There is a large burden associated with elements of the prior rule language such as the demonstration of applicability of the plant-specific transition break size, and the requirements relative to low power or shutdown PRA, which are not justified.

• Significant updates are needed from the prior rule language to address these overly burdensome requirements.

• Schedule impacts meeting the strategic aspirations of the industry for extended fuel cycles.

Alignment with Principles of Good Regulation

• This alternative would provide additional clarity, reliability, and efficiencies regarding analytical requirements that reduces uncertainties and permits use of increased enrichments, higher burnups, and improved margins for additional power uprates.

Alternative #3 Summary: Performance-based acceptance criteria for the extent and consequences of dispersed fuel would be added to the existing post quench ductility requirements. Guidance would be developed for NRC-acceptable methods.

Pros:

• Could be significantly less limiting for core designs than a no HBU rupture criterion (depending on implementation).

• Actual technical resolution to conclusively define an acceptable level of fuel dispersal (current regulation doesnt explicitly preclude but assumes insignificant, this would remove that gray area).

• Uniformity across industry in resolution.

• The methods could be reasonable if combined with less conservatism-best estimate approaches (Alternative #2)

Cons:

• Requires new research. Testing has focused largely on fragmentation, rather than consequences of dispersal.

• Vendors: New methods and codes.

• Licensees: New analysis and submittals.

Attachment Page 17

• Fleet wide criterion is challenging due to differences in plant design (e.g., core, assemblies, RVs, ECCS) and transient response.

• NRC guidance would take many years to develop and the outcome is unknown.

Guidance would also be susceptible to new research findings (e.g., planned TREAT in-pile testing).

• Typical NRC-developed regulations and regulatory guidance are onerous and too conversative.

• NRCs confirmatory tools, which may be deemed necessary to complete approvals to implement new requirements, would take years to develop and validate. Code-to-code differences in predictions always take time to resolve.

• Large amount NRC unknowns: PIRT, research, ISG, criterion, methods, etc.

• No rupture may still be required for certain LBLOCA scenarios, plant types, and SBLOCA.

• Does not address impact of dispersal beyond ECCS performance, e.g., other safety-related SSCs.

Alignment with Principles of Good Regulation

• This alternative would provide additional clarity, reliability, and efficiencies regarding analytical requirements that reduces uncertainties and permits use of increased enrichments and higher burnups.

Modified Alternative #4:

Alternative #4 with recommended modifications provides many benefits with respect to supporting industry initiatives, enhancing regulatory stability and predictability, and improving overall nuclear safety.

Pros:

• Applicable to both BWRs and PWRs.

• Regulatory framework utilizing risk insights.

• Performance-based regulatory framework (e.g., Safety-related SSCs performance judged against risk-informed, dose limits).

• Technology-neutral regulatory framework (i.e., applicable to wide array of fuel designs including ATF).

• Allows credit for state-of-knowledge and industry improvements in the area of beyond design basis mitigating strategies through the EOP, BDB, FLEX and SAMG procedures along with the E-Plan.

Attachment Page 18

• Depending on the rigor of fuel dispersal predictions necessary to demonstrate compliance to radiological consequence limits, quantifying core-wide fuel dispersion:

o may not require significant changes to existing LOCA EMs (to predict core-wide distribution of burst rods and fuel dispersal),

o may not require any additional research to fill data gaps in fuel fragmentation and dispersal empirical database, and o may be readily, continuously verified based on core reload depletions and core follow.

• Captures and assesses potential impacts of new fuel designs (e.g., increased enrichment) and/or changes in plant operations (e.g., power uprates) on public health and safety (i.e., radiological consequences).

• Relatively low cost (compared with Alt. #2, #3) for NRC staff to promulgate rule changes and develop regulatory infrastructure and for industry to prepare implementation infrastructure. Similar costs to Alt. #5.

• Relatively fast schedule (compared with Alt. #2, #3) for NRC staff to promulgate rule changes and develop regulatory infrastructure and for industry to prepare implementation infrastructure. Similar schedule to Alt. #5.

• Minimizes fuel management restrictions and fuel design changes necessary to implement. This promotes improved fuel cycle economics.

• Supports 24-month core reload cycles for PWRs.

• Supports fuel batch size reduction and spent fuel storage requirement reduction for BWRs.

Cons

• New DBA-LOCA radiological requirement may be more restrictive than current plants licensing bases (i.e., MHA-LOCA bounds DBA-LOCA).

• The use of risk insights for addressing downstream effects is key for this alternative.

Otherwise, this alternative turns into alternative 3, with multi-year effort/research.

• This alternative requires rulemaking and this regulatory process has been historically unpredictable and lengthy.

• This alternative requires regulatory guidance document development and issuance.

This process has been historically unpredictable and lengthy.

Alignment with Principles of Good Regulation

• This alternative would provide a simple, easy to implement solution for the entire nuclear industry (BWRs, PWRs, SMRs, and other advanced new technologies). It

Attachment Page 19 enhances regulatory predictability by eliminating uncertainties in addressing FFRD. It enables use of increased enrichments, higher burnups, and provides reactivity flexibility without imposing fuel management restrictions to support additional power uprates. It supports spent fuel storage reduction.

Alternative #5 with proposed industry modifications:

Alternative #5 with recommended modifications provides many benefits with respect to supporting industry initiatives, enhancing regulatory stability and predictability, and improving overall nuclear safety.

Pros:

• Addresses FFRD in a timely and cost-effective manner.

• Does not require additional FFRD testing or research.

• Based largely on an existing regulatory framework (LBB) that must be extended to address policy restrictions on its application to a new analysis area.

• Reduces high level waste by implementing high burnup fuel in a timelier manner.

This reduces occupational dose by reducing the number of dry cask loading campaigns and site boundary dose by reducing the number of dry cask.

• Quicker implementation of more efficient core designs reduces the radiological hazards and transportation risk of the entire fuel cycle.

• Support early application of 24-MFC for all PWR, reducing occupational dose by reducing refueling outages by 25%.

• Minimizes the burden on scarce NRC and Industry fuel experts by limiting the need for additional research. These resources can be employed in other more critical areas, benefiting the public.

• Support the continued economic viability of the existing LWR fleet and therefore the US and international environmental objectives or reduced greenhouse gases.

Cons:

• Does not apply to BWRs.

Alignment with Principles of Good Regulation

• This alternative would provide additional clarity, reliability, and efficiencies regarding analytical requirements that reduces uncertainties and permits use of increased enrichments, higher burnups, and provides reactivity flexibility without imposing fuel management restrictions to support additional power uprates.

Cumulative Effects of Regulation

Attachment Page 20 The cumulative effects of regulation (CER) describe the challenges that licensees or other impacted entities (such as Agreement State agency partners) may face while implementing new regulatory positions, programs, and requirements (e.g., rules, generic letters, backfits, inspections). The CER is an organizational effectiveness challenge that results from a licensee or impacted entity implementing a number of complex positions, programs, or requirements within a limited implementation period and with available resources (which may include limited available expertise to address a specific issue). The NRC has implemented CER enhancements to the rulemaking process to facilitate public involvement throughout the rulemaking process. Therefore, the NRC is specifically requesting comment on the cumulative effects that may result from this proposed rulemaking. In developing comments on the regulatory basis, consider the following questions:

1. In light of any current or projected CER challenges, how should the NRC provide sufficient time to implement the new proposed requirements, including changes to programs and procedures?

Industry Response:

The proposed alternatives in the IE Rulemaking Regulatory Basis are numerous with varied potential impacts. The uncertainty is too large at this point to determine the CER impacts at this time. The industry will provide the impacts to CER once clarity on the specifics for each alternative is fully developed.

2. If CER challenges currently exist or are expected, what should be done to address them? For example, if more time is required for implementation of the new requirements, what period of time is sufficient?

Industry Response:

The proposed alternatives in the IE Rulemaking Regulatory Basis are numerous with varied potential impacts. The uncertainty is too large at this point to determine the CER challenges at this time. The industry will provide the CER challenges once clarity on the specifics for the rulemaking is fully developed.

3. What other (NRC or other agency) regulatory actions (e.g., orders, generic communications, license amendment requests inspection findings of a generic nature) influence the implementation of the proposed rules requirements?

Industry Response:

The proposed FFRD alternatives in the IE Rulemaking Regulatory Basis are numerous with varied potential impacts. The uncertainty is too large at this point to determine the additional regulatory impacts at this time for the alternatives proposed. For regulatory activities on transportation, industry recognizes the potential need to harmonize NRC, DOT and IAEA transportation regulations.

4. What are the unintended consequences, and how should they be addressed?

Industry Response:

The proposed options in the IE rulemaking regulatory basis are numerous with varied potential impacts. The uncertainty is too large to determine unintended consequences at this time. The

Attachment Page 21 industry will provide this information once clarity on the specifics for the rulemaking is fully developed.