SUPPLEMENTARY INFORMATION:

Table of Contents

I. Obtaining Information and Submitting Comments

II. Rulemaking Procedure

III. Background

IV. Discussion of Changes

V. Voluntary Consensus Standards

VI. Agreement State Compatibility

VII. Plain Writing

VIII. Environmental Assessment and Finding of No Significant Impact

IX. Regulatory Planning and Review

X. Paperwork Reduction Act Statement

XI. Regulatory Flexibility Certification

XII. Regulatory Analysis

XIII. Backfitting and Issue Finality

XIV. Congressional Review Act

XV. Availability of Documents

I. Obtaining Information and Submitting Comments

A. Obtaining Information

Please refer to Docket ID NRC-2026-2476 when contacting the NRC about the availability of information for this action. You may obtain publicly available information related to this action by any of the following methods:

• Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2026-2476. Address questions about NRC dockets to Helen ( printed page 46244) Chang, telephone: 301-415-3228, email: Helen.Chang@nrc.gov. For technical questions contact the individuals listed in the FOR FURTHER INFORMATION CONTACT section of this document.
• NRC's Agencywide Documents Access and Management System (ADAMS): You may obtain publicly available documents online in the ADAMS Public Documents collection at https://www.nrc.gov/​reading-rm/​adams.html. To begin the search, select “Begin ADAMS Public Search.” For problems with ADAMS, please contact the NRC's Public Document Room (PDR) reference staff at 1-800-397-4209, at 301-415-4737, or by email to PDR.Resource@nrc.gov. For the convenience of the reader, instructions about obtaining materials referenced in this document are provided in the “Availability of Documents” section.
• NRC's PDR: The PDR, where you may examine and order copies of publicly available documents, is open by appointment. To make an appointment to visit the PDR, please send an email to PDR.Resource@nrc.gov or call 1-800-397-4209 or 301-415-4737, between 8 a.m. and 4 p.m. eastern time, Monday through Friday, except Federal holidays.

B. Submitting Comments

The NRC encourages electronic comment submission through the Federal rulemaking website ( https://www.regulations.gov). Please include Docket ID NRC-2026-2476 in your comment submission.

The NRC cautions you not to include identifying or contact information that you do not want to be publicly disclosed in your comment submission. The NRC will post all comment submissions at https://www.regulations.gov as well as enter the comment submissions into ADAMS. The NRC does not routinely edit comment submissions to remove identifying or contact information.

If you are requesting or aggregating comments from other persons for submission to the NRC, then you should inform those persons not to include identifying or contact information that they do not want to be publicly disclosed in their comment submission. Your request should state that the NRC does not routinely edit comment submissions to remove such information before making the comment submissions available to the public or entering the comment into ADAMS.

II. Rulemaking Procedure

This rule is limited to the changes contained in Amendment No. 10 to Certificate of Compliance (CoC) No. 1032 and does not include other aspects of the HI-STORM FW Cask System design. The NRC is using the direct final rule procedure to issue this amendment because it represents a limited and routine change to an existing (CoC) that is expected to be non-controversial. Adequate protection of public health and safety continues to be reasonably assured. The amendment to the rule will become effective on October 6, 2026. However, if the NRC receives any significant adverse comment on this direct final rule by August 24, 2026, then the NRC will publish a document that withdraws this action and will subsequently address the comments received in a final rule as a response to the companion proposed rule published in the Proposed Rules section of this issue of the Federal Register or as otherwise appropriate. In general, absent significant modifications to the proposed revisions requiring republication, the NRC will not initiate a second comment period on this action.

A significant adverse comment is a comment where the commenter explains why the rule would be inappropriate, including challenges to the rule's underlying premise or approach, or would be ineffective or unacceptable without a change. A comment is adverse and significant if:

(1) The comment opposes the rule and provides a reason sufficient to require a substantive response in a notice-and-comment process. For example, a substantive response is required when:

(a) The comment causes the NRC to reevaluate (or reconsider) its position or conduct additional analysis;

(b) The comment raises an issue serious enough to warrant a substantive response to clarify or complete the record; or

(c) The comment raises a relevant issue that was not previously addressed or considered by the NRC.

(2) The comment proposes a change or an addition to the rule, and it is apparent that the rule would be ineffective or unacceptable without incorporation of the change or addition.

(3) The comment causes the NRC to make a change (other than editorial) to the rule, CoC, or technical specifications.

III. Background

Section 218(a) of the Nuclear Waste Policy Act of 1982, as amended, requires that “[t]he Secretary [of the Department of Energy] shall establish a demonstration program, in cooperation with the private sector, for the dry storage of spent nuclear fuel at civilian nuclear power reactor sites, with the objective of establishing one or more technologies that the [Nuclear Regulatory] Commission may, by rule, approve for use at the sites of civilian nuclear power reactors without, to the maximum extent practicable, the need for additional site-specific approvals by the Commission.” Section 133 of the Nuclear Waste Policy Act states, in part, that “[t]he Commission shall, by rule, establish procedures for the licensing of any technology approved by the Commission under Section 219(a) [sic: 218(a)] for use at the site of any civilian nuclear power reactor.”

To implement this mandate, the Commission approved dry storage of spent nuclear fuel in NRC-approved casks under a general license by publishing a final rule that added a new subpart K in part 72 of title 10 of the Code of Federal Regulations (10 CFR) entitled “General License for Storage of Spent Fuel at Power Reactor Sites” (55 FR 29181; July 18, 1990). This rule also established a new subpart L in 10 CFR part 72 entitled “Approval of Spent Fuel Storage Casks,” which contains procedures and criteria for obtaining NRC approval of spent fuel storage cask designs. The NRC subsequently issued a final rule on March 28, 2011 (76 FR 17019), that approved the HI-STORM FW System design and added it to the list of NRC-approved cask designs in § 72.214 as CoC No. 1032.

IV. Discussion of Changes

On March 1, 2024, Holtec International submitted a request to the NRC to amend CoC No. 1032. Holtec International supplemented its request on the following dates: September 16, 2024, December 12, 2024, February 28, 2025, July 28, 2025, September 11, 2025, and January 30, 2026. Amendment No. 10 revises the CoC to:

• Introduce the HI-STORM FW Extended Configuration. This version of the HI-STORM FW system is an anchored configuration that allows storage of two multi-purpose canisters (MPCs) stored vertically within a specially designed system of two storage overpacks.
• Incorporation of a methodology to develop site-specific loading patterns in Chapter 4 of the HI-STORM FW final safety analysis report (FSAR) and inclusion of higher maximum per canister and per cell limits for those patterns.
• Incorporation of the “Topical Report on the Radiological Fuel Qualification Methodology for Dry Storage Systems,” Holtec Report HI-2210161-A. Related details and requirements are specified in the new Appendix B to Chapter 5 of the FSAR. ( printed page 46245)
• Reduce MPC-44 minimum cooling time from 3 years to 1 year, and MPC-37P minimum cooling time from 1.6 years to 1 year.
• Revise the FSAR methodology for HI-TRAC VW missile penetration to allow site-specific analysis to take credit for the HI-TRAC VW water jacket shell.
• Minor editorial change to the CoC and providing a clarification to AppendixB of the CoC by updating the MPC-89 maximum fuel assembly length in Table 2.1-1 to 181.5 inches, which includes configurations involving a damaged fuel canister or a damaged fuel isolator.

The changes to the aforementioned documents are identified with revisions bars in the margin of each document.

As documented in the preliminary safety evaluation report, the NRC performed a safety evaluation of the proposed CoC amendment request. The NRC determined that this amendment does not reflect a significant change in design or fabrication of the cask. Specifically, the NRC determined that the design of the cask would continue to maintain confinement, shielding, and criticality control in the event of each evaluated accident condition. In addition, any resulting occupational exposure or offsite dose rates from the implementation of Amendment No. 10 would remain well within the limits specified by 10 CFR part 20, “Standards for Protection Against Radiation.” Thus, the NRC found there will be no significant change in the types or amounts of any effluent released, no significant increase in the individual or cumulative radiation exposure, and no significant increase in the potential for or consequences from radiological accidents.

The NRC staff determined that the amended HI-STORM FW cask design, when used under the conditions specified in the CoC, the technical specifications, and the NRC's regulations, will meet the requirements of 10 CFR part 72; therefore, adequate protection of public health and safety will continue to be reasonably assured. When this direct final rule becomes effective, persons who hold a general license under § 72.210 may, consistent with the license conditions under § 72.212, load spent nuclear fuel into HI-STORM FW casks that meet the criteria of Amendment No. 10 to CoC No. 1032.

V. Voluntary Consensus Standards

The National Technology Transfer and Advancement Act of 1995 (Pub. L. 104-113) requires that Federal agencies use technical standards that are developed or adopted by voluntary consensus standards bodies unless the use of such a standard is inconsistent with applicable law or otherwise impractical. In this direct final rule, the NRC revises the HI-STORM FW Cask System design listed in § 72.214, “List of approved spent fuel storage casks.” This action does not constitute the establishment of a standard that contains generally applicable requirements.

VI. Agreement State Compatibility

Under the “Agreement State Program Policy Statement” approved by the Commission on October 2, 2017, and published in the Federal Register on October 18, 2017 (82 FR 48535), this rule is classified as Compatibility Category NRC—Areas of Exclusive NRC Regulatory Authority. The NRC program elements in this category are those that relate directly to areas of regulation reserved to the NRC by the Atomic Energy Act of 1954, as amended, or the provisions of 10 CFR chapter I. Therefore, compatibility is not required for program elements in this category.

VII. Plain Writing

The Plain Writing Act of 2010 (Pub. L. 111-274) requires Federal agencies to write documents in a clear, concise, and well-organized manner. The NRC has written this document to be consistent with the Plain Writing Act as well as the Presidential Memorandum, “Plain Language in Government Writing,” published June 10, 1998 (63 FR 31885).

VIII. Environmental Assessment and Finding of No Significant Impact

Under the National Environmental Policy Act (NEPA) of 1969, as amended, and the NRC's regulations in 10 CFR part 51, “Environmental Protection Regulations for Domestic Licensing and Related Regulatory Functions,” the NRC has determined that this direct final rule, if adopted, would not be a major Federal action significantly affecting the quality of the human environment and, therefore, an environmental impact statement is not required. The NRC has made a finding of no significant impact on the basis of this environmental assessment. This environmental assessment and finding of no significant impact can be tracked with identification number NEPA ID EAXX-429-00-000-1778667092.

A. The Action

The action is to amend § 72.214 to revise the Holtec International HI-STORM FW listing within the “List of approved spent fuel storage casks” to include Amendment No. 10 to CoC No. 1032.

B. The Need for the Action

This direct final rule amends the CoC for Holtec International HI-STORM FW design within the list of approved spent fuel storage casks to allow power reactor licensees to store spent fuel at reactor sites in casks with the approved modifications under a general license. Specifically, Amendment No. 10 revises the CoC for the HI-STORM FW dry storage system to incorporate several enhancements. These changes include the introduction of the HI-STORM FW Extended Configuration, an anchored design that accommodates two multi-purpose canisters stored vertically within specially engineered overpacks; adoption of a methodology for developing site-specific loading patterns with higher allowable per-canister and per-cell heat-load limits; incorporation of a radiological fuel-qualification methodology, including associated analytical requirements; reduction of minimum cooling-time requirements for certain multi-purpose canister models based on updated evaluations; and refinement of the missile-impact analysis methodology to allow site-specific credit for the HI-TRAC VW water-jacket shell. The amendment also includes a minor editorial clarification. Collectively, these revisions update the HI-STORM FW CoC and Final Safety Analysis Report consistent with Holtec's requested changes.

C. Environmental Impacts of the Action

On July 18,1990 (55 FR 29181), the NRC issued an amendment to 10 CFR part 72 to provide for the storage of spent fuel under a general license in cask designs approved by the NRC. The potential environmental impact of using NRC-approved storage casks was analyzed in the environmental assessment for the 1990 final rule. The environmental assessment for this Amendment No. 10 tiers off of the environmental assessment for the July 18, 1990, final rule. Tiering on past environmental assessments is a standard process under the National Environmental Policy Act of 1969, as amended.

Holtec International HI-STORM FW is designed to mitigate the effects of design basis accidents that could occur during storage. Design basis accidents account for human-induced events and the most severe natural phenomena reported for the site and surrounding area. Postulated accidents analyzed for an independent spent fuel storage installation, the type of facility at which a holder of a power reactor operating license would store spent fuel in casks in accordance with 10 CFR part 72, can ( printed page 46246) include tornado winds and tornado-generated missiles, a design basis earthquake, a design basis flood, an accidental cask drop, lightning effects, fire, explosions, and other incidents.

This amendment does not reflect a significant change in design or fabrication of the cask. Because there are no significant design or process changes, any resulting occupational exposure or offsite dose rates from the implementation of Amendment No. 10 would remain well within the 10 CFR part 20 limits. The NRC has also determined that the design of the cask as modified by this rule would maintain confinement, shielding, and criticality control in the event of an accident. Therefore, the proposed changes will not result in any radiological or non-radiological environmental impacts that significantly differ from the environmental impacts evaluated in the environmental assessment supporting the July 18, 1990, final rule. There will be no significant change in the types or significant revisions in the amounts of any effluent released, no significant increase in the individual or cumulative radiation exposures, and no significant increase in the potential for, or consequences from, radiological accidents. The NRC documented its safety findings in the preliminary safety evaluation report.

D. Alternative to the Action

The alternative to this action is to deny approval of Amendment No. 10 and not issue the direct final rule. Consequently, any 10 CFR part 72 general licensee that seeks to load spent nuclear fuel into Holtec International HI-STORM FW in accordance with the changes described in proposed Amendment No. 10 would have to request an exemption from the requirements of §§ 72.212 and 72.214. Under this alternative, interested licensees would have to prepare, and the NRC would have to review, a separate exemption request, thereby increasing the administrative burden upon the NRC and the costs to each licensee. The environmental impacts would be the same as the proposed action.

E. Alternative Use of Resources

Approval of Amendment No. 10 to CoC No. 1032 would result in no irreversible and irretrievable commitments of Federal resources.

F. Agencies and Persons Contacted

No agencies or persons outside the NRC were contacted in connection with the preparation of this environmental assessment.

G. Finding of No Significant Impact

The environmental impacts of the action have been reviewed under the requirements in the National Environmental Policy Act of 1969, as amended, and the NRC's regulations in subpart A of 10 CFR part 51. Based on the foregoing environmental assessment, the NRC concludes that this direct final rule, “List of Approved Spent Fuel Storage Casks: Holtec International HI-STORM Flood/Wind System, CoC No. 1032, Amendment No. 10,” will not have a significant effect on the human environment. Therefore, the NRC has determined that an environmental impact statement is not necessary for this direct final rule.

IX. Regulatory Planning and Review

Executive Order (E.O.) 12866, as amended by E.O. 14215, provides that the Office of Information and Regulatory Affairs (OIRA) will determine whether a regulatory action is significant as defined by E.O. 12866 and will review significant regulatory actions. OIRA determined that this direct final rule is not a significant regulatory action under E.O. 12866

X. Paperwork Reduction Act Statement

This direct final rule does not contain any new or amended collections of information subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.). Existing collections of information were approved by the Office of Management and Budget, approval number 3150-0132.

Public Protection Notification

The NRC may not conduct or sponsor, and a person is not required to respond to a collection of information unless the document requesting or requiring the collection displays a currently valid OMB control number.

XI. Regulatory Flexibility Certification

Under the Regulatory Flexibility Act of 1980 (5 U.S.C. 605(b)), the NRC certifies that this direct final rule will not, if issued, have a significant economic impact on a substantial number of small entities. This direct final rule affects only nuclear power plant licensees and Holtec Internation. These entities do not fall within the scope of the definition of small entities set forth in the Regulatory Flexibility Act or the size standards established by the NRC (§ 2.810).

XII. Regulatory Analysis

On July 18, 1990 (55 FR 29181), the NRC issued an amendment to 10 CFR part 72 to provide for the storage of spent nuclear fuel under a general license in cask designs approved by the NRC. Any nuclear power reactor licensee can use NRC-approved cask designs to store spent nuclear fuel if (1) it notifies the NRC in advance; (2) the spent fuel is stored under the conditions specified in the cask's CoC; and (3) the conditions of the general license are met. A list of NRC-approved cask designs is contained in § 72.214. On June 8, 2011 (76 FR 33121), the NRC issued an amendment to 10 CFR part 72 that approved the HI-STORM FW System by adding it to the list of NRC-approved cask designs in § 72.214.

On March 1, 2024, and as supplemental on September 16, 2024, December 12, 2024, February 28, 2025, July 28, 2025, September 11, 2025, and January 30, 2026, Holtec International submitted a request to amend the HI-STORM FW System as described in Section IV, “Discussion of Changes,” of this document.

The alternative to this action is to withhold approval of Amendment No. 10 and to require any 10 CFR part 72 general licensee seeking to load spent nuclear fuel into Holtec International HI-STORM FW under the changes described in Amendment No. 10 to request an exemption from the requirements of §§ 72.212 and 72.214. Under this alternative, each interested 10 CFR part 72 licensee would have to prepare, and the NRC would have to review, a separate exemption request, thereby increasing the administrative burden upon the NRC and the costs to each licensee.

Approval of this direct final rule is consistent with previous NRC actions. Further, as documented in the preliminary safety evaluation report and environmental assessment, this direct final rule will have no adverse effect on public health and safety or the environment. This direct final rule has no significant identifiable impact or benefit on other government agencies. Based on this regulatory analysis, the NRC concludes that the requirements of this direct final rule are commensurate with the NRC's responsibilities for public health and safety and the common defense and security. No other available alternative is believed to be as satisfactory; therefore, this action is recommended.

XIII. Backfitting and Issue Finality

The NRC has determined that the backfit rule (§ 72.62) does not apply to this direct final rule. Therefore, a backfit analysis is not required. This direct final rule revises CoC No. 1032 for the Holtec International HI-STORM FW, as currently listed in § 72.214. The revision consists of the changes in Amendment ( printed page 46247) No. 10 previously described, as set forth in the revised CoC and technical specifications.

Amendment No. 10 to CoC No. 1032 for the Holtec International HI-STORM FW was initiated by Holtec International and was not submitted in response to new NRC requirements, or an NRC request for amendment. Amendment No. 10 applies only to new casks fabricated and used under Amendment No. 10. These changes do not affect existing users of the Holtec International HI-STORM FW, and the current Amendment No. 7 continues to be effective for existing users. While current users of this storage system may comply with the new requirements in Amendment No. 10, this would be a voluntary decision on the part of current users.

For these reasons, Amendment No. 10 to CoC No. 1032 does not constitute backfitting under § 72.62 or § 50.109(a)(1), or otherwise represent an inconsistency with the issue finality provisions applicable to combined licenses in 10 CFR part 52. Accordingly, the NRC has not prepared a backfit analysis for this rulemaking.

XIV. Congressional Review Act

This direct final rule is not a rule as defined in the Congressional Review Act.

XV. Availability of Documents

The documents identified in the following table are available to interested persons as indicated.

The NRC may post materials related to this document, including public comments, on the Federal rulemaking website at https://www.regulations.gov under Docket ID NRC-2026-2476. In addition, the Federal rulemaking website allows members of the public to receive alerts when changes or additions occur in a docket folder. To subscribe: (1) navigate to the docket folder (NRC-2026-2476); (2) click the “Subscribe” link; and (3) enter an email address and click on the “Subscribe” link.

For the reasons set out in the preamble and under the authority of the Atomic Energy Act of 1954, as amended; the Energy Reorganization Act of 1974, as amended; the Nuclear Waste Policy Act of 1982, as amended; and 5 U.S.C. 552 and 553; the NRC is adopting the following amendments to 10 CFR part 72:

91 FR 46243