Holtec HI-STORM UMAX spent fuel storage amendment

Content

ACTION:

Direct final rule.

SUMMARY:

The U.S. Nuclear Regulatory Commission (NRC) is amending its spent fuel storage regulations by revising the Holtec International
HI-STORM UMAX Canister Storage System listing within the “List of approved spent fuel storage casks” to include Amendment
No. 5 to Certificate of Compliance No. 1040. Amendment No. 5 revises the certificate of compliance to include two new versions
of the HI-STORM UMAX design (Version B1 and B2).

DATES:

This direct final rule is effective June 16, 2026, unless significant adverse comments are received by May 4, 2026. If this
direct final rule is withdrawn as a result of such comments, timely notice of the withdrawal will be published in the
Federal Register
. Comments received after this date will be considered if it is practical to do so, but the NRC is able to ensure consideration
only for comments received on or before this date. Comments received on this direct final rule will also be considered to
be comments on a companion proposed rule published in the Proposed Rules section of this issue of the
Federal Register
.

ADDRESSES:

Submit your comments, identified by Docket ID NRC-2026-0562, at https://www.regulations.gov. If your material cannot be submitted using https://www.regulations.gov, call or email the individual listed in the
FOR FURTHER INFORMATION CONTACT
section of this document for alternate instructions.

Do not include any personally identifiable information (such as name, address, or other contact information) or confidential
business information that you do not want publicly disclosed. All comments are public records; they are publicly displayed
exactly as received, and will not be deleted, modified, or redacted. Comments may be submitted anonymously.

Follow the search instructions on https://www.regulations.gov to view public comments.

You can read a plain language description of this direct final rule at https://www.regulations.gov/docket/NRC-2026-0562. For additional direction on obtaining information and submitting comments, see “Obtaining Information and Submitting Comments”
in the
SUPPLEMENTARY INFORMATION
section of this document.

FOR FURTHER INFORMATION CONTACT:

Amy McKenna, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; email: Amy McKenna@nrc.gov.

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-2026-0562 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-2026-0562. Address questions about NRC dockets to Helen Chang, telephone: 301-415-3228, email: Helen.Chang@nrc.gov. For technical questions contact the individual 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-2026-0562 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. 5 to Certificate of Compliance No. 1040 and does not include
other aspects of the Holtec International HI-STORM UMAX 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 certificate of compliance 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 June 16, 2026. However, if the NRC receives any significant adverse comment
on this direct final rule by May 4, 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, certificate of compliance, 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
6, 2015 (80 FR 12073), as corrected (80 FR 15679; March 25, 2015), that approved the Holtec International HI-STORM UMAX Canister
Storage System design and added it to the list of NRC-approved cask designs in § 72.214 as Certificate of Compliance No. 1040.

IV. Discussion of Changes

On December 14, 2023 (ML23348A302), Holtec International submitted a request to the NRC to amend Certificate of Compliance
No. 1040. Holtec International supplemented its request on the following dates: April 18, 2024 (ML24136A189), September 19,
2024 (ML24263A280), January 31, 2025 (ML25031A419), August 4, 2025 (ML25216A284), and October 6, 2025 (ML25279A207). Amendment
No. 5 revises the certificate of compliance to include two new versions of the HI-STORM UMAX design (Version B1 and B2) with
new lid features designed to enhance the safety of the cask system by minimizing exposure of the canisters to air with salt
particles.

As documented in the preliminary safety evaluation report, the NRC performed a safety evaluation of the proposed certificate
of compliance 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. 5 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 Holtec International HI-STORM UMAX Canister Storage System cask design, when used
under the conditions specified in the certificate of compliance, 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 Holtec International HI-STORM UMAX Canister
Storage System casks that meet the criteria of Amendment No. 5 to Certificate of Compliance No. 1040.

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 Holtec International HI-STORM
UMAX Canister Storage System cask 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 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-429-00-000-1770783521.

A. The Action

The action is to amend § 72.214 to revise the Holtec International HI-STORM UMAX Canister Storage System listing within the
“List of approved spent fuel storage casks” to include Amendment No. 5 to Certificate of Compliance No. 1040.

B. The Need for the Action

This direct final rule amends the certificate of compliance for the Holtec International HI-STORM UMAX Canister Storage System
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. 5 revises the certificate
of compliance to include two new versions of the HI-STORM UMAX design (Version B1 and B2).

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.
5 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 UMAX Canister Storage System 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 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. 5 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. 5 and not issue the direct final rule. Consequently, any
10 CFR part 72 general licensee that seeks to load spent nuclear fuel into a Holtec International HI-STORM UMAX Canister Storage
System in accordance with the changes described in proposed Amendment No. 5 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. 5 to Certificate of Compliance No. 1040 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, “Environmental Protection Regulations for Domestic
Licensing and Related Regulatory Functions.” Based on the foregoing environmental assessment, the NRC concludes that this
direct final rule, “Holtec International HI-STORM UMAX Canister Storage System, Certificate of Compliance No. 1040, Amendment
No. 5,” 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.

XI. Regulatory Planning and Review

Executive Order (E.O.) 12866

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 Office of Management and Budget 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 International. 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 certificate of compliance; and (3) the conditions of the general license are met. A list of NRC-approved
cask designs is contained in § 72.214. On March 6, 2015 (80 FR 12073), as corrected (80 FR 15679; March 25, 2015), the NRC
issued an amendment to 10 CFR part 72 that approved the Holtec International HI-STORM UMAX Canister Storage System by adding
it to the list of NRC-approved cask designs in § 72.214.

On April 18, 2024 (ML24136A189), and as supplemented on September 19, 2024 (ML24263A280), January 31, 2025 (ML25031A419),
August 4, 2025 (ML25216A284), and October 6, 2025 (ML25279A207) submitted a request to amend the HI-STORM UMAX Canister Storage
System as described in Section IV, “Discussion of Changes,” of this document.

The alternative to this action is to withhold approval of Amendment No. 5 and to require any 10 CFR part 72 general licensee
seeking to load spent nuclear fuel into a Holtec International HI-STORM UMAX Canister Storage System under the changes described
in Amendment No. 5 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 Certificate of Compliance No. 1040 for the Holtec International HI-STORM UMAX
Canister Storage System, as currently listed in § 72.214. The revision consists of the changes in Amendment No. 5 previously
described, as set forth in the revised certificate of compliance and technical specifications.

Amendment No. 5 to Certificate of Compliance No. 1040 for the HI-STORM UMAX Canister Storage System was initiated by Holtec
International and was not submitted in response to new NRC requirements, or an NRC request for amendment. Amendment No. 5
applies only to new casks fabricated and used under Amendment No. 5. These changes do not affect existing users of the Holtec
International HI-STORM UMAX Canister Storage System, and the current Amendment No. 4 continues to be effective for existing
users. While current users of this storage system may comply with the new requirements in Amendment No. 5, this would be a
voluntary decision on the part of current users.

For these reasons, Amendment No. 5 to Certificate of Compliance No. 1040 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.

| Document | ADAMS
accession No./Web link/Federal Register
citation |
| --- | --- |
| Proposed Certificate of Compliance and Technical Specifications Documents | |
| User Need Memo for Amendment No. 5 of the Certificate of Compliance No. 1040 for the Holtec HI-STORM UMAX Storage System | ML26013A271 |
| Proposed CoC No. 1040, Amendment No. 5 | ML26013A272 |
| Proposed Technical Specifications for CoC No. 1040, Amendment No. 5, Appendix A | ML26013A273 |
| Proposed Technical Specification for CoC No. 1040, Amendment No. 5, Appendix B | ML26013A274 |
| Preliminary Safety Evaluation Report for CoC No. 1040, Amendment No. 5 | ML26013A275 |
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-2026-0562. 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-2026-0562); (2) click
the “Subscribe” link; and (3) enter an email address and click on the “Subscribe” link.

List of Subjects in 10 CFR Part 72

Administrative practice and procedure, Hazardous waste, Indians, Intergovernmental relations, Nuclear energy, Penalties, Radiation
protection, Reporting and recordkeeping requirements, Security measures, Spent fuel, Whistleblowing.

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:

PART 72—LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR-RELATED

GREATER THAN CLASS C WASTE

Regulatory Text 1. The authority citation for part 72 continues to read as follows:

Authority:

Atomic Energy Act of 1954, secs. 51, 53, 57, 62, 63, 65, 69, 81, 161, 182, 183, 184, 186, 187, 189, 223, 234, 274 (42 U.S.C.
2071, 2073, 2077, 2092, 2093, 2095, 2099, 2111, 2201, 2210e, 2232, 2233, 2234, 2236, 2237, 2238, 2273, 2282, 2021); Energy
Reorganization Act of 1974, secs. 201, 202, 206, 211 (42 U.S.C. 5841, 5842, 5846, 5851); National Environmental Policy Act
of 1969 (42 U.S.C. 4332); Nuclear Waste Policy Act of 1982, secs. 117(a), 132, 133, 134, 135, 137, 141, 145(g), 148, 218(a)
(42 U.S.C. 10137(a), 10152, 10153, 10154, 10155, 10157, 10161, 10165(g), 10168, 10198(a)); 44 U.S.C. 3504 note.

1. In § 72.214, revise Certificate of Compliance No. 1040 to read as follows:

§ 72.214 List of approved spent fuel storage casks.

---

Certificate Number: 1040.

Initial Certificate Effective Date: April 6, 2015, superseded by Initial Certificate, Revision 1 Effective Date: April 21, 2025.

Amendment Number 1 Effective Date: September 8, 2015, superseded by Amendment Number 1, Revision 1 Effective Date: April 21, 2025.

Amendment Number 2 Effective Date: January 9, 2017, superseded by Amendment Number 2, Revision 1 Effective Date: April 21, 2025.

Amendment Number 3 Effective Date: [Reserved].

Amendment Number 4 Effective Date: January 25, 2021.

Amendment Number 5 Effective Date: June 16, 2026.

SAR Submitted by: Holtec International, Inc.

SAR Title: Final Safety Analysis Report for the Holtec International HI-STORM UMAX Canister Storage System.

Docket Number: 72-1040.

Certificate Expiration Date: April 6, 2035.

Model Number: MPC-37, MPC-89.

---

Dated: March 20, 2026. For the Nuclear Regulatory Commission.

Michael King, Executive Director for Operations. [FR Doc. 2026-06373 Filed 4-1-26; 8:45 am] BILLING CODE 7590-01-P

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