The Sunset Rule-Aircraft Impact Assessment

In response to Executive Order (E.O.) 14270, “Zero-Based Regulatory Budgeting to Unleash American Energy,” the NRC published a direct final rule, “The Sunset Rule,” in the Federal Register on December 3, 2025 (90 FR 55621). The direct final rule amended certain NRC regulations to insert a conditional sunset date. The rule included an amendment that would have established a conditional sunset date in the NRC's provisions for aircraft impact assessments (AIA) in section 50.150, “Aircraft impact assessment,” in title 10 of the Code of Federal Regulations (10 CFR).

As described in the direct final rule, if the NRC were to receive significant adverse comments by January 2, 2026, the NRC would withdraw the action and address the comments in a subsequent final rule. The NRC received 6 comment submissions on the amendment to sunset the AIA regulations that contained comments that NRC deemed are significant and adverse. Accordingly, in a document published on January 8, 2026 (91 FR 553), the NRC withdrew the amendment to add a conditional sunset date to 10 CFR 50.150.

In this action, the NRC responds to the significant adverse public comments received on the proposed rule, “The Sunset Rule” (90 FR 55699; December 3, 2025). After additional consideration of these comments, the NRC re-evaluated its position and determined that it is appropriate to add a sunsetting clause in the NRC's AIA regulations at 10 CFR 50.150. The NRC is issuing this final rule to amend its regulations to insert a conditional sunset date for the NRC's requirements for AIA at 10 CFR 50.150.

Executive Order 14270 directs the NRC to issue a rule inserting a conditional sunset date into each of its regulations that are in effect as of the date of the E.O. (90 FR 15643; April 15, 2025) and were issued in whole or in part pursuant to the following statutes, as amended: the Atomic Energy Act of 1954, the Energy Reorganization Act of 1974, and the Nuclear Waste Policy Act of 1982. The conditional sunset date for covered regulations is to be one year after the effective date of the sunset rule. The E.O. directs the NRC to issue a sunset rule “to the extent consistent with applicable law” and provides that the E.O. does not apply to “regulatory permitting regimes authorized by statute.” For purposes of implementing this E.O., regulations that provide standards and requirements for NRC license and permit holders or applicants constitute the NRC's “regulatory permitting regime.” Thus, the scope of this rulemaking is generally limited to those regulations that do not fit into one or more of the following three categories: (1) regulations that could not be sunset “consistent with applicable law” because they are necessary to fulfill the NRC's statutory mandate to provide for the common defense and security and to protect public health

and safety; (2) regulations that are part of the NRC's “regulatory permitting regimes authorized by statute”; or (3) regulations that do not implement one of the three NRC-specific statutes identified in the E.O. (e.g., regulations that implement government-wide requirements such as the Freedom of Information Act of 1969). The vast majority of the NRC's regulations fit into one of these three categories. Nonetheless, the NRC identified several regulations, including its AIA regulations at 10 CFR 50.150, that although they fall into one or more of these categories, they are not being used or no longer serve their original purpose and thus fall within the spirit and intent of the E.O. as “outdated.”

As stated in E.O. 14270, the sunsetting provision states a conditional sunset date that is one year after the effective date of this final rule and provides that, before that sunset date, the NRC will offer the public an opportunity to comment on the costs and benefits of the regulation that is being conditionally sunset. The NRC will issue a separate notice describing the comment opportunity after this final rule is effective. Following the opportunity for the public to comment on the sunset regulation's costs and benefits, the NRC may extend the conditional sunsetting date if warranted and may do so as many times as appropriate. However, if the NRC does not extend the conditional sunset date, then following the sunset date, the NRC will consider the sunset regulation to no longer be effective, will not seek to enforce it, and will remove the sunset regulation from the CFR and make necessary conforming changes.

The President has directed the NRC to issue this zero-based regulating rule. Section 4(a) of E.O. 14270 states that “each of the Covered Agencies shall issue a sunset rule,” and further specifies the terms of that rule. Accordingly, the NRC lacks any discretion over whether to undertake this sunsetting rule. The President's direction provides an independent, and sufficient, justification for this rulemaking. However, the E.O. does not direct the NRC to rescind or reissue any particular regulation. The NRC retains its full authority to issue and repeal regulations under the three relevant statutes and their amendments. The President has directed only the manner in which the NRC is to review and sunset the relevant regulations.

The regulations in 10 CFR 50.150 are safety enhancements that are not necessary for the NRC to meet its statutory mission under the Atomic Energy Act of 1954, as amended, to provide reasonable assurance of adequate protection of the public health and safety and provide for the common defense and security. When the AIA rule was promulgated in 2009 (74 FR 28112; June 12, 2009) (the 2009 final rule), the NRC quantified the costs of the rule but did not quantify the benefits and concluded that the key qualitative benefit of the rule was an “improvement in knowledge” of how a new reactor would address beyond- design-basis hazards, such as a deliberate large aircraft impact. At the time, the NRC concluded that qualitative benefits outweighed the cost of the rule. However, as discussed in section IV.E, “Cost/Benefit Analysis,” of this document, several key assumptions have changed since the assessment was performed. As a result of those changes, it is not clear that the cost of implementation of the AIA rule is justified by the increase in safety provided by the rule.

Subsequent to the issuance of the 2009 final rule, the NRC issued regulations that now require nuclear power plant license-related applicants to address aircraft impact hazards both inside and outside the design basis. For example, 10 CFR part 53, “Risk-Informed, Technology-Inclusive Regulatory Framework for Commercial Nuclear Plants,” requires a comprehensive risk assessment that illustrates the NRC's evolution in thought about how a newly licensed plant could address beyond-design-basis hazards. These concepts are discussed further in sections IV.B, “Discussion of 10 CFR 50.155,” and IV.C, “Discussion of 10 CFR part 53,” of this document. Beyond changes to the NRC's regulatory framework, since 2009 there have been substantial increases in security at commercial aviation facilities as well as hardened access to aircraft cockpits, making the initiating event analyzed under 10 CFR 50.150 significantly less likely to occur.

Currently operating facilities will not be affected by sunsetting this provision because the analyses required by 10 CFR 50.150 are incorporated into a plant's licensing basis. Any licensee-initiated change to the facility will be controlled through the change process in 10 CFR 50.59, “Changes, tests, and experiments,” as discussed in the response to public comment in section IV.D of this document. Further, applicants for new reactor permits, licenses, and certifications still must assess hazards from aircraft accidents, as required by 10 CFR part 100, “Reactor Site Criteria,” to determine whether these hazards should be considered within the design basis.\1\ Thus, while 10 CFR 50.150 constituted part of the NRC's permitting regime authorized by statute, it is no longer needed. A sunset date will allow this outdated and duplicative regulation to roll off the books. At the same time, if evidence emerges in the interim indicating a continued need for this regulation, the agency can extend the sunset date as appropriate.

\1\ NRC guidance for reviewing aircraft hazards analyses in nuclear power plant license applications is provided in NUREG-0800, “Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition,” Section 3.5.1.6, “Aircraft Hazards,” Revision 4 (ML100331298). This document describes the regulations that require the plant siting evaluation, including 10 CFR part 100 and 10 CFR 52.79, “Contents of applications; technical information in final safety analysis report” and the considerations for incorporating aircraft impacts into the design basis.

As discussed in the December 3, 2025, direct final rule, 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.\2\ A comment is adverse and significant if:

\2\ Administrative Conference of the United States, Adoption of Recommendations, (60 FR 43108-43111; August 18, 1995).

(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.

The NRC determined that 6 of the 15 public submissions received on the proposed rule contained comments on the AIA amendment that were deemed by NRC to be significant and adverse as they caused the NRC to re-evaluate its position. These comment submissions were provided by 3 private citizens, 2

state agencies, and an academic organization and are available as shown in section XIV, “Availability of Documents,” of this document and on the Federal e-Rulemaking website at https://www.regulations.gov under Docket ID No. NRC-2025-0479.

The NRC organized the comments into 5 categories. This section summarizes each category and provides the NRC's response.

One commenter expressed concern that adequate protection would not be maintained if 10 CFR 50.150 were eliminated.

The NRC disagrees with this comment. In the preamble to the 2009 final rule, the Commission stated that the rule was based both on enhanced public health and safety and enhanced common defense and security but was not necessary for adequate protection. Because the rule was not identified as necessary for adequate protection when promulgated, it is not necessary to address whether removal of the requirements maintains adequate protection, except as related to circumstances not considered in the initial issuance of the rule as described later in these comment responses.

Multiple commenters discussed their concerns regarding the purpose of 10 CFR 50.150. Specifically, they claimed that the original basis for the rule was both an improvement in knowledge and to provide an enhanced level of protection beyond adequate protection, so the elimination of this requirement could weaken the safety standards.

The NRC disagrees with these comments. The NRC acknowledges that sunsetting the AIA rule removes a requirement for some facilities to consider, at the design stage, the effects of intentional large commercial aircraft impact. However, applicants for new reactor permits, licenses, and certifications still must assess hazards from aircraft impacts, as required by 10 CFR part 100, to determine whether these hazards should be considered within the design basis. As discussed in the NRC's comment response in section IV.B of this document, paragraph (b)(2) of 10 CFR 50.155, “Mitigation of beyond- design-basis events,” provides that fires and explosions such as those that could result from a large aircraft impact must be considered as beyond-design-basis events. Section 182 of the Atomic Energy Act of 1954, as amended, states that the NRC regulates license applications to a standard of “adequate protection to the health and safety of the public.” As previously noted, the 2009 final rule was not found to be necessary for adequate protection. Accordingly, the NRC concludes that sunsetting the AIA rule would not result in a degradation of safety standards to a degree that adequate protection of public health and safety would not be maintained.

Several commenters expressed concern over the discussion in the proposed rule regarding 10 CFR 50.155 and its use to justify sunsetting 10 CFR 50.150. Specifically, commenters noted that 10 CFR 50.155 addresses natural phenomena and the mitigation of the resulting fires and explosions, whereas 10 CFR 50.150 involves large commercial aircraft. In addition, commenters expressed concern that 10 CFR 50.155 is not germane to the initial design of the reactor facility but rather focuses on after-the-fact response. Commenters stated that when 10 CFR 50.155 was promulgated in 2019, it was intended to complement, not duplicate or supersede 10 CFR 50.150; therefore, 10 CFR 50.155 is not more comprehensive and cannot be credited in the NRC's reasoning for sunsetting 10 CFR 50.150.

The NRC agrees, in part, and disagrees, in part, with the comments.

The NRC disagrees that 10 CFR 50.155 only addresses natural phenomena. The requirements of 10 CFR 50.155(b)(1) address “external events from natural phenomena.” However, in the preamble for the 10 CFR 50.155 final rule (84 FR 39684; August 9, 2019), the Commission explained that this language was “meant to differentiate these requirements from those that previously existed in Sec. 50.54(hh)(2) that are now located in Sec. 50.155(b)(2), and which address beyond- design-basis external events leading to loss of large areas of the plant due to explosions and fire.” The Commission also stated that “[a]lthough the wording of Sec. 50.155(b)(2) differs from that of previous Sec. 50.54(hh)(2), no substantive change in the requirements is intended.” As such, the requirements in 10 CFR 50.155(b)(2) to develop extensive damage mitigation guidelines (EDMGs) are intended to encompass a range of external events, including both natural and human- induced phenomena.

The Commission also noted that the EDMGs were maintained in the regulations because the conditions that necessitate the development of EDMGs may result from aircraft impact and a beyond-design-basis security event that could introduce kinetic energy into the spent fuel pool independent from the decay heat of the fuel. Thus, the requirements of 10 CFR 50.155(b)(2) are intended to specifically address losses of large areas of the facility caused by fires and explosions resulting from events such as aircraft impacts.

The NRC agrees that 10 CFR 50.150 and 50.155 have slightly different objectives. 10 CFR 50.150 is intended to ensure certain large, commercial aircraft impacts are mitigated by design with reduced operator action, while 10 CFR 50.155 is intended to address mitigation of beyond-design-basis events through development and implementation of mitigation strategies, and was determined to be required to maintain adequate protection of public health and safety. However, as discussed in the previous comment responses, the requirements at 10 CFR 50.150 are not needed to maintain reasonable assurance of adequate protection of public health and safety.

Several commenters noted that the then-proposed 10 CFR part 53 had not yet been promulgated as a final rule and therefore could not support the argument to sunset 10 CFR 50.150.

The NRC agrees, in part, and disagrees, in part, with the comment.

The NRC agrees that the 10 CFR part 53 final rule had not been promulgated at the time the December 8, 2025, Sunset Rule was issued.

However, the NRC disagrees that the risk-informed, performance- based thinking in the then-proposed 10 CFR part 53 could not support the justification for sunsetting 10 CFR 50.150. Licenses issued under 10 CFR parts 50 and 52 are largely based on deterministic analyses of the safety of the facility relying on the general design criteria in appendix A, “General Design Criteria for Nuclear Power Plants,” to 10 CFR part 50, “Domestic Licensing of Production and Utilization Facilities.” In contrast, under 10 CFR part 53, applicants are required to perform a comprehensive risk assessment of their reactor design to identify potential failures, susceptibility to internal and external hazards, and other contributing factors that could pose a risk to public health and safety. The reference to the proposed 10 CFR part 53 in the Sunset Rule was intended to illustrate the evolution in thought about how newly licensed plants could address beyond-design- basis hazards and can be used to inform current and future technical decisions, such as the decision to add a sunset provision to 10 CFR 50.150. This is further illustrated by the agency's decision to remove the AIA requirement from the final 10 CFR part 53 rule language for the reasons discussed in

Section III and because part 53 applicants will have to consider how to mitigate the broader potential plant impacts that could result from an event such as the impact of a large aircraft.

A commenter stated that the removal of 10 CFR 50.150 would allow licensees to remove the analyses being credited in the licensing bases under 10 CFR 50.59.

The NRC agrees with the comment.

The NRC agrees that removal of 10 CFR 50.150 would allow certain licensees to make changes to portions of their facilities' designs related to aircraft impacts, subject to the requirements of 10 CFR 50.59. Section 50.59(c)(4) specifies that the provisions in 10 CFR 50.59 do not apply to changes to the facility or procedures when the applicable regulations establish more specific criteria for accomplishing such changes. Section 50.150(c) provides such criteria for control of changes to the facility related to the AIA. Removal of 10 CFR 50.150 would revert control of such changes to 10 CFR 50.59. The use of the well-established 10 CFR 50.59 change control process does not impact the proposal to insert a conditional sunset date in the AIA rule.

The AIA analyses themselves are not required to be submitted to the NRC. The provisions of 10 CFR 50.150(b) require the preliminary or final safety analysis report (as applicable) to include only a description of (1) the design features and functional capabilities identified in 10 CFR 50.150(a)(1), and (2) how these design features and functional capabilities meet the assessment requirements of 10 CFR 50.150(a)(1). Additionally, the 2009 final rule makes clear that the intent of the rule was to enhance the robustness of facilities to aircraft impacts at the design stage. The Commission stated in the final rule preamble that “once the design features and functional capabilities for addressing an aircraft impact have been incorporated into a nuclear power plant's design, the goal of this final rule has been achieved in that consideration of aircraft impacts has been factored into the design.”

The NRC notes that the 10 CFR 50.59 change control process does not allow licensees to change or remove portions of the facility or the final safety analysis report related to AIA without evaluation of the safety impacts under 10 CFR 50.59(c). The 10 CFR 50.59 process therefore provides reasonable assurance of adequate protection of public health and safety in the event a licensee decides to pursue facility changes following the sunsetting of the AIA rule.

Several commenters said that without a formal cost-benefit analysis, the AIA rule cannot be sunset.

The NRC agrees with this comment.

This final rule does not sunset the AIA rule; rather, this rule inserts a conditional sunset provision in 10 CFR 50.150, in accordance with E.O. 14270. Before the NRC takes regulatory action to remove the AIA regulations, the NRC will perform a full regulatory analysis and will request public comments on that cost-benefit analysis. After reviewing those comments, the NRC will determine whether to remove the AIA regulations from 10 CFR part 50.

Several of the commenters took issue with the NRC's statement in the proposed rule that, if reconsidered today, the cost of implementation of the AIA rule would not be justified by the increase in safety for future reactors.

The NRC agrees in part, and disagrees in part, with this comment.

The NRC agrees that the NRC did not include details to support that statement in the proposed rule. However, the NRC reviewed the cost- benefit analysis from the initial promulgation of the AIA rule and found several key assumptions have changed.

One of the assumptions in the cost-benefit analysis for the 2009 final rule was that the NRC considered it unlikely that a request for a new construction permit or operating license would be submitted to the NRC for approval during the next 20 years. However, since 2009, the NRC has received multiple additional applications for construction permits and combined licenses. A number of other applicants and pre-applicants have expressed interest in additional construction permit, operating license, and combined license applications.

Additionally, due to the nature of the operating fleet and new reactor license reviews under way at the time the 2009 final rule was under development, the cost-benefit analysis for that rulemaking was focused on large, light-water reactor (LWR) designs. The large LWRs considered in the rulemaking featured robust containments that provide inherent protection against aircraft impacts, so the estimated costs were predominantly focused on the cost of performing the AIA and the associated NRC review. The new reactor landscape has changed significantly since 2009, with small modular reactors and advanced non- light-water reactors playing a more significant role in the new reactors being pursued by industry. These reactor designs may eliminate or substantially reduce the potential for energetic releases that could expel radionuclides from the reactor. As a result of the low likelihood of release, these designs may not require a containment similar to that of large LWRs. While this may result in less inherent protection from aircraft impacts when compared to large LWRs, it is at least partially offset by increased inherent and passive safety in the design and smaller plant footprints. Nonetheless, the NRC expects the corresponding cost of incorporating protection against aircraft impacts into advanced reactor designs would be substantially greater than the costs considered in the original AIA rule. Considering the AIA rule was an enhancement to safety beyond what is needed for reasonable assurance of adequate protection and other regulations will continue to require applicants to address aircraft impact hazards both inside and outside the design basis as needed for adequate protection, as discussed in sections IV.A and B of this document, the NRC expects that the anticipated costs would not justify the safety benefit in the current reactor landscape.

The NRC has concluded that these comments do not provide a basis to materially change the NRC's decision to provisionally sunset the AIA rule.

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

ADAMS accession No./Federal

Document Register citation

Notice, “Adoption of 60 FR 43108

Recommendations,” August 18, 1995. Final Rule, “Consideration of 74 FR 28112

Aircraft Impacts for New Nuclear

Power Reactors,” June 12, 2009. Final Rule, “Mitigation of Beyond- 84 FR 39684

Design-Basis Events,” August 9,

2019. Direct Final Rule, “The Sunset 90 FR 55621

Rule,” December 3, 2025. Proposed Rule, “The Sunset Rule,” 90 FR 55699

December 3, 2025. Notice, “The Sunset Rule,” January 91 FR 553

8, 2026. NUREG-0800, Chapter 3, SRP Section ML100331298

3.5.1.6, Reg. 4, “Aircraft

Hazards,” March 9, 2010. Executive Order 12866, “Regulatory 58 FR 51735

Planning and Review,” October 4,

1993. Executive Order 14154, “Unleashing 90 FR 8353

American Energy,” January 29, 2025. Executive Order 14192, “Unleashing 90 FR 9065

Prosperity Through Deregulation,”

February 6, 2025. Executive Order 14215, “Ensuring 90 FR 10447

Accountability for All Agencies,”

February 24, 2025. Executive Order 14270, “Zero-Based 90 FR 15643

Regulatory Budgeting to Unleash

American Energy,” April 15, 2025. Executive Order 14300, “Ordering the 90 FR 22587

Reform of the Nuclear Regulatory

Commission, May 29, 2025. Presidential Memorandum, “Plain 63 FR 31885

Language in Government Writing,”

June 10, 1993.

Public Comments

Comment No. 3, Fred Schofer, December ML25349A140

8, 2025. Comment No. 6, Barry Quigley, ML25364A101

December 29, 2025. Comment No. 7, Fred Dilger, State of ML26002A007

Nevada, January 2, 2026. Comment No. 10, Jason Schwartz, ML26002A076

Institute for Policy Integrity,

January 2, 2026. Comment No. 11, Stewart Schneider, ML26005A018

January 2, 2026. Comment No. 13, Alyese Peterson, ML26008A119

State of New York, January 2, 2026.

The NRC may post materials related to this document on the Federal rulemaking website at https://www.regulations.gov under Docket ID NRC- 2026-0166. 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- 2026-0166); (2) click the “Subscribe” button; and (3) enter an email address and click on the “Subscribe” button.

Administrative practice and procedure, Antitrust, Backfitting, Classified information, Criminal penalties, Education, Emergency planning, Fire prevention, Fire protection, Intergovernmental relations, Nuclear power plants and reactors, Penalties, Radiation protection, Reactor siting criteria, Reporting and recordkeeping requirements, 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; and 5 U.S.C. 552 and 553, the NRC is adopting the following amendment to 10 CFR part 50.

PART 50--DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES

0 1. The authority citation for part 50 continues to read as follows:

Authority: Atomic Energy Act of 1954, secs. 11, 101, 102, 103, 104, 105, 108, 122, 147, 149, 161, 181, 182, 183, 184, 185, 186,

187, 189, 223, 234 (42 U.S.C. 2014, 2131, 2132, 2133, 2134, 2135, 2138, 2152, 2167, 2169, 2201, 2231, 2232, 2233, 2234, 2235, 2236, 2237, 2239, 2273, 2282); Energy Reorganization Act of 1974, secs. 201, 202, 206, 211 (42 U.S.C. 5841, 5842, 5846, 5851); Nuclear Waste Policy Act of 1982, sec. 306 (42 U.S.C. 10226); National Environmental Policy Act of 1969 (42 U.S.C. 4332); 44 U.S.C. 3504 note; Sec. 109, Pub. L. 96-295, 94 Stat. 783.

0 2. In Sec. 50.150, add paragraph (d) to read as follows:

Sec. 50.150 Aircraft impact assessment.

* * * * *

(d) Sunsetting provisions. This section shall cease to have effect on April 8, 2027, unless the NRC determines that the cessation deadline should be extended to a date not more than 5 years in the future after offering the public an opportunity to provide input on the costs and benefits of this section and considering that input. The NRC will publish a document in the Federal Register announcing its determination and revising or removing this section accordingly.

Dated: April 2, 2026.

For the Nuclear Regulatory Commission. Michael King, Executive Director for Operations. [FR Doc. 2026-06747 Filed 4-7-26; 8:45 am] BILLING CODE 7590-01-P