AC 450.45-1

U.S.

Department of Transportation Federal Aviation Administration Advisory Circular Subject: Launch and Reentry of Space Nuclear Date: 10/20/2023 AC No: AC 450.45-1 Systems Initiated By: AST-1 This Advisory Circular (AC) guides applicants through the launch and reentry licensing process when space nuclear systems (SNS) are present on a launch or reentry vehicle. This AC provides a means of compliance and guidance for applicants proposing to launch or reenter SNS for meeting the requirements for a safety review under § 450.45. This AC also applies to applicants for a payload determination for SNS under 14 CFR § 450.43.

This AC provides an accepted means of compliance with the regulatory requirements of §§ 450.43 and 450.45 related to SNS. It presents one, but not the only, acceptable means of compliance with the associated regulatory requirements. The contents of this document do not have the force and effect of law and are not meant to bind the public in any way. The document is intended only to provide clarity to the public regarding existing requirements under the law or agency policies.

If you have suggestions for improving this AC, you may use the Advisory Circular Feedback form at the end of this AC.

Minh A. Nguyen Executive Director, Office of Strategic Management Commercial Space Transportation

Launch and Reentry of Space Nuclear Systems AC 450.45-1 Contents Paragraph Page ii

1 Purpose5

2 Applicability6

3 Applicable Regulations and Related Documents7

4 Definition of Terms11

5 Acronyms and Symbols14

6 Pertinent Regulations for Space Nuclear Systems16

6.1 Safety Challenges16

6.2 FAA Launch and Reentry License Regulations16

6.3 Other Agency Regulations21

7 Tier Levels and Safety Guidelines23

7.1 NSPM-20 Tier Level Definitions23

7.2 SNS Safety Guidelines26

7.3 Notes on the Tier Level Definitions27

8 Space Nuclear System Licensing Process30

8.1 Overview of Licensing Process30

8.2 Licensing Process for the Launch of an SNS31

8.3 Nuclear Safety Analyses to Demonstrate Acceptable Public Health and Safety31

8.4 Space Nuclear System Design34

8.5 Interagency Nuclear Safety Review Board34

8.6 Application Determination35

Appendix A. Nuclear Safety Information and Analyses36

A.1 Scope36

A.2 SNS Device and Mission Description36

A.3 Radiological Material Report37

A.4 Criticality Hazard Analysis39

A.5 Criticality Safety Analysis40

A.6 Optional Comparison to Existing Nuclear Analyses42

A.7 Radiological Hazard Analysis44

A.8 High Fidelity Radiological Safety Analysis45

A.9 Radiological Emergency Response Plan50

Launch and Reentry of Space Nuclear Systems AC 450.45-1 Contents Paragraph Page iii

A.10 Tier Level Determination51

A.11 Safety Analysis Report51

Appendix B. Guideline Safety Recommendations53

B.1 Scope53

B.2 Nuclear Safety Themes53

Appendix C. Historical SNS Accident81

C.1 Cosmos 95481

Appendix D. References82

Appendix E. Radiological Units88

Launch and Reentry of Space Nuclear Systems AC 450.45-1 iv Figures Number Page

Figure 1– NSPM-20 Tier Level Determination Aid25

Figure 2 – Considerations Given to Various PER’s27

Figure 3 – License Evaluation Process30

Figure 4 – Nuclear Safety Analysis Flow Chart32

Figure 5 – SNS Mission Risk Drivers55

Figure 6 – Cosmos 954 Debris Map (Gummer, et al. 1980)81

Tables Number Page

Table 1– Partner Agencies19

Table 2 – Additional Government Agencies Consulted for SNS Policy or Payload Review20

Table 3 – Government Agencies with Roles in SNS Licensing22

Table 4 – Nuclear Material Disposal Options34

Table 5 – Sample Radiological Material Report38

Table 6 – Accident Environments for HFRSA Consideration46

Table 7 – Information Produced by a HFRSA47

Table 8 – Design Considerations for All SNS57

Table 9 – Guidelines for SNS Designed to Operate in Earth Orbit59

Table 10 – Guidelines for Designing Fission Based SNS62

Table 11 – Guidelines Applicable to Design of SNS Host Spacecraft64

Table 13 – SNS Analysis Guidelines68

Table 14 - Guidelines for SNS Validation, Verification, and Testing70

Table 15 – Guidelines for SNS Launch Planning72

Table 16 – Guidelines for Planning SNS Operations in Space74

Table 17 – Guidelines for Planning SNS EOM75

Table 18 – Guidelines for SNS Launch Operations77

Table 19 – Guidelines for SNS Operations in Space79

Table 20 – Guidelines for EOM Disposal80

Launch and Reentry of Space Nuclear Systems AC 450.45-1 5 1 PURPOSE.

The purpose of this AC is to guide applicants through the launch and reentry licensing process when SNS are present on a launch or reentry vehicle. This AC provides a means of compliance and guidance for applicants proposing to launch or reenter SNS for meeting the requirements for a safety review under § 450.45. This AC also applies to applicants seeking a payload determination for SNS under 14 CFR § 450.43. In accordance with § 450.45(e)(6), the FAA will evaluate the launch or reentry of any radionuclide on a case-by-case basis and issue an approval if the FAA finds that the launch or reentry is consistent with public health and safety, safety of property, and national security and foreign policy interests of the United States. The guidance in this AC can also be used for reference by mission planners and operators in the commercial space industry, designers and manufacturers of launch vehicles or reentry vehicles that may transport SNS, and designers, manufacturers, and operators of SNS, to assist them in understanding the safety analysis and regulatory processes that the FAA will apply in reviewing applications for commercial launches or reentries involving SNS. Spaceports may also find portions of this AC useful for understanding the public safety and regulatory concerns with SNS.

1.1 Level of Imperatives.

This AC presents one, but not the only, acceptable means of compliance with the associated regulatory requirements. The FAA will consider other means of compliance that an applicant may elect to present. In addition, an operator may tailor the provisions of this AC to meet its unique needs, provided the changes are accepted as a means of compliance by the FAA. Throughout this document, the word “must” characterizes statements that directly follow from regulatory text and therefore reflect regulatory mandates. The word “should” describes an option that, if used would constitute a means to comply with the regulation; variation from the provisions of this AC is possible, but must satisfy the regulation to constitute a means of compliance. The word “may” describes variations or alternatives allowed within the accepted means of compliance set forth in this AC. The term “applicant” is used throughout this AC to describe any party seeking any approval, determination, or license from the FAA under 14 CFR Chapter III for commercial space operations involving an SNS.

Launch and Reentry of Space Nuclear Systems AC 450.45-1 6 2 APPLICABILITY.

2.1 The guidance in this AC is for launch and reentry vehicle applicants and operators required to comply with 14 CFR part 450. The guidance in this AC is for those seeking a launch or reentry vehicle operator license, licensed operators seeking to renew or modify an existing vehicle operator license, and FAA commercial space transportation evaluators.

2.2 The material in this AC is advisory in nature and does not constitute a regulation. This guidance is not legally binding in its own right and will not be relied upon by the FAA as a separate basis for affirmative enforcement action or other administrative penalty.

Conformity with this guidance document (as distinct from existing statutes and regulations) is voluntary only, and nonconformity will not affect rights and obligations under existing statutes and regulations. This AC describes acceptable means, but not the only means, for demonstrating compliance with the applicable regulations.

2.3 The material in this AC does not change or create any additional regulatory requirements, nor does it authorize changes to, or deviations from, existing regulatory requirements.

Launch and Reentry of Space Nuclear Systems AC 450.45-1 7 3 APPLICABLE REGULATIONS AND RELATED DOCUMENTS.

The documents referenced in this chapter refer to the current revisions or regulatory authorities’ accepted revisions.

3.1 Related United States Office of the President Documents.

• Executive Order 12114, Environmental Effects Abroad of Major Federal Actions, dated January 4, 1979. https://www.archi ves.gov/federalregister/codification/executive-order/12114.html.

• Executive Order 13972, Promoting Small Modular Reactors for National Defense and Space Exploration, dated January 5, 2021;

https://www.federalregister.gov/documents/2021/01/14/2021-01013/promotingsmall-modular-reactors-for-national-defense-and-space-exploration.

• Memorandum on Space Policy Directive -5, Cybersecurity Principles for Space Systems, dated September 4, 2020;

https://trumpwhitehouse.archives.gov/presidential-actions/memorandum-spacepolicy-directive-5-cybersecurity-principles-space-systems/.

• Memorandum on Space Policy Directive -6, Memorandum on the National Strategy for Space Nuclear Power and Propulsion, dated December 16, 2020;

https://trumpwhitehouse.archives.gov/presidential-actions/memorandum-nationalstrategy-space-nuclear-power-propulsion-space-policy-directive-6/.

• NSPM-20, Presidential Memorandum on Launch of Spacecraft Containing Space Nuclear Systems, dated August 20, 2019;

https://trumpwhitehouse.archives.gov/presidential-actions/presidentialmemorandum-launch-spacecraft-containing-space-nuclear-systems/.

3.2 Related Council on Environmental Quality Regulations.

• Title 40, Code of Federal Regulations (CFR) Chapter V, Subchapter A, National Environmental Policy Act Implementing Regulations, last amended May 20, 2022.

3.3 Related Department of Defense (DOD) Manual.

• Department of the Air Force Manual (DAFMAN) 91-110, Nuclear Safety Review and Launch Approval for Space or Missile Use of Radioactive Material, dated February 24, 2022.

3.4 Related Department of Energy Regulations.

• Title 10 CFR part 835, Occupational Radiation Protection, last amended October 11, 2022.

Launch and Reentry of Space Nuclear Systems AC 450.45-1 8

3.5 Related Department of Transportation Orders and Regulations.

• Department of Transportation (DOT) Order 5610.1C, Procedures for Considering Environmental Impacts, dated September 18, 1979.

https://www.transportation.gov/sites/dot.gov/files/docs/Procedures_Considering_En vironmental_Impacts_5610_1C.pdf.

• Transportation of Radioactive Materials; Memorandum of Understanding Between the NRC and DOT, (44 FR 38690, dated July 2, 1979). https://www.nrc.gov/aboutnrc/regulatory/enforcement/moudot.pdf.

• Title 49 CFR part172, Hazardous Materials Table, Special Provisions, Hazardous Materials Communications, Emergency Response Information, Training Requirements, And Security Plans.

• Title 49 CFR 173 Subpart I – Class 7 (Radioactive) Materials.

3.6 Related Environmental Protection Agency Regulations and Reports.

• Environmental Protection Agency (EPA) Federal Guidance Report No. 11, EPA-520/1-88-020, Limiting Values of Radionuclide Intake and Air Concentration and Dose Conversion Factors for Inhalation, Submersion, and Ingestion, dated September 1988. https://www.epa.gov/radiation/federal-guidance-r adiationprotection.

• EPA, Federal Guidance Report No. 15, EPA-402-R19-002, External Exposure to Radionuclides in Air, Water and Soil, revised August 2019.

https://www.epa.gov/radiation/federal-guidance-radiation-protection.

• EPA, Revision to the PAG Manual: Protective Action Guide (PAG) for Drinking Water After a Radiological Incident, revised January 19, 2017.

https://www.federalregister.gov/documents/2017/01/19/2017-01230/revision-to- thepag-manual-protective-action-guide-pag-for-drinking-water-after-a-radiological

• EPA, Protective Action Questions & Answers for Radiological and Nuclear Emergencies: A companion document to the U.S. Environmental Protection Agency Protection Action Guide (PAG) Manual,” EPA-402/K-22/002, January 2022.

https://www.epa.gov/radiation/pag-public-communication-resources.

3.7 Related FAA Order and Regulations.

• FAA Order 1050.1F Environmental Impacts: Policies and Procedures, dated July 16, 2015.

• Title 14 CFR Chapter III, Commercial Space Transportation, Federal Aviation Administration, Department of Transportation.

3.8 Related Federal Emergency Management Agency Programs.

• Federal Emergency Management Agency (FEMA) National Incident Management System, dated October 10, 2017. https://www.fema.gov/sites/default/files/2020- 07/fema_nims_doctrine-2017.pdf.

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• FEMA National Response Framework, dated October 28, 2019.

https://www.fema.gov/sites/default/files/2020- 04/NRF_FINALApproved_2011028.pdf.

• FEMA Nuclear/Radiological Incident Annex to the Response and Recovery Federal Interagency Operational Plans, dated May 2023.

https://www.fema.gov/sites/default/files/documents/fema_incident -annex_nuclearradiological.pdf.

• FEMA Radiological Emergency Preparedness Program Manual, FEMA P-1028, dated December 23, 2019. https://www.fema.gov/sites/default/files/2020- 06/FEMA_REP_Program_Manual_Dec_2019.pdf.

3.9 Related NASA Standards and Documents.

• National Aeronautics and Space Administration (NASA), Nuclear Safety, Procedural Requirements, NPR 8715.26, Nuclear Flight Safety, dated February 3, 2023.

• NASA Standard 8719.24B, NASA Payload Safety Requirements Table, https://standards.nasa.gov/sites/default/files/standards/NASA/B//NASA-S TD- 871924B-Annex.pdf.

3.10 Related Nuclear Regulatory Commission (NRC) Definitions and Regulations.

• Nuclear Regulatory Commission NRC Full Text Glossary.

https://www.nrc.gov/reading-rm/basic-ref/glossary.html.

• Title 10 CFR, Chapter I. Nuclear Regulatory Commission.

3.10.1 Related International Atomic Energy Agency Report and Regulations.

• International Atomic Energy Agency (IAEA), Advisory Material for the IAEA Regulations for the Safe Transport of Radioactive Material, 2018 Edition, SSG-26.

Revision 1. https://www.iaea.org/publications/14685/advisory-ma terial-for-the-iaearegulations-for-the-safe-transport-of-radioactive-material-2018-edition.

• IAEA, Convention on Early Notification of a Nuclear Accident and Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency, updated 2002.

https://www.iaea.org/sites/default/files/publications/documents/infcircs/1986/infcirc 335a11-infcirc336a12.pdf.

• IAEA, Regulations for the Safe Transport of Radioactive Material, SSR-6 Rev.1.

2018 edition, https://www.iaea.org/publications/12288/regulations-for-t he-safetransport-of-radioactive-material.

• IAEA, The Role of Nuclear Power and Nuclear Propulsion in the Peaceful Exploration of Space, 2005. https://wwwpub.iaea.org/MTCD/publications/PDF/Pub1197_web.pdf.

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• IAEA, Criteria for Use in Preparedness and Response for a Nuclear or Radiological Emergency, GSG-2 General Safety Guide, 2011.

https://www.iaea.org/publications/8506/criteria- for-use-in-preparedness-andresponse-for-a-nuclear-or-radiological-emergency.

• IAEA, Operational Intervention Levels for Reactor Emergencies and Methodology for their Derivation, EPR-NPP-OILs, 2017, https://www.iaea.org/publications/11093/operational-intervention-le vels-for-reactoremergencies

3.10.2 Related United Nations Conventions, Documents, Resolution and Treaties.

• United Nations Treaty on the Non-Proliferation of Nuclear Weapons;

https://www.un.org/disarmament/wmd/nuclear/npt/

• United Nations Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies, Resolution 222, dated 1966.

https://www.unoosa.org/oosa/en/ourwork/spacelaw/treaties/introouterspacetreaty.ht ml

3.11 Related U.S. Department of Health and Human Services, Food and Drug Administration Program Alignment Recommendation.

• United States Food and Drug Administration, Accidental Radioactive Contamination of Human Food and Animal Feeds: Recommendations for State and Local Agencies, dated August 13, 1998. https://www.fda.gov/about-f da/fdaorganization/fda-program-alignment.

Launch and Reentry of Space Nuclear Systems AC 450.45-1 11 4 DEFINITION OF TERMS.

For this AC, the terms from 14 CFR § 401.7 and the following definitions apply:

4.1 Anticipated Operational Occurrences Those conditions of normal operation, which are expected to occur one or more times during the life of an SNS, including single failures that can be anticipated to occur during its operational life.

4.2 Biosphere Also known as the ecosphere, this is the worldwide sum of the earth’s ecosystems including its hydrosphere, and lithosphere. It is the life-supporting stratum of the Earth’s surface, extending from a few kilometers into the atmosphere to the deep-sea vents of the ocean. The biosphere is a global ecosystem composed of living organisms (biota) and the abiotic (nonliving) factors from which the organisms derive their energy and nutrients.

4.3 Collision Physical contact between two objects at a relative speed greater than 1 kilometer per hour, or any physical contact between two objects that can cause physical damage to either object.

4.4 Critical or Criticality The normal operating condition of a fission reactor, in which nuclear fuel sustains a fission chain reaction and each fission event releases enough neutrons to sustain an ongoing series of reactions.

4.5 Criticality Accident The release of energy that is a result of accidentally producing a critical or supercritical fission chain reaction.

4.6 Decay Heat The heat produced by the decay of radioactive fission products after a reactor has been shut down.

4.7 Delayed Critical State of a reactor that is critical based on the contribution of delayed neutrons to the overall neutron flux, i.e., a reactor with a controllable fission chain reaction.

4.8 Delayed Neutrons Neutrons from nuclei produced by beta decay following fission. They follow fission by intervals of seconds to minutes.

Launch and Reentry of Space Nuclear Systems AC 450.45-1 12

4.9 Dose Equivalent A measure of the biological damage to living tissue because of radiation exposure.

Calculated as the product of the absorbed dose in tissue multiplied by a quality factor and other necessary modifying factors.

4.10 Exposure Absorption of ionizing radiation or ingestion of a radioisotope.

4.11 Fission The splitting of an atom, which releases a considerable amount of energy, usually in the form of heat, radiation, at least two lighter elements, and neutrons. Fission may occur spontaneously but is commonly neutron-induced for nuclear reactors.

4.12 High-fidelity Radiological Safety Analysis (HFRSA) A high-fidelity radiological safety analysis applies probabilistic risk assessment methods and calculates the risk to the public for all reasonably foreseeable events and failures of safety-critical systems during normal and malfunction operations in all mission phases.

4.13 Low-Enriched Uranium (LEU) Uranium fuel in which the weight percent of U-235 in the uranium is less than 20%.

4.14 Prompt Critical A fission reactor that is critical only due to the prompt neutrons and is therefore supercritical due to the additional presence of delayed neutrons.

4.15 Prompt Neutrons Neutrons emitted immediately during the fission process.

4.16 Shutdown Margin The instantaneous amount of reactivity by which a reactor is subcritical or would be subcritical from its present condition assuming the reactivity control system is fully activated to minimize reactivity, except the single reactivity control device of highest reactivity worth is fully maximizing reactivity.

4.17 Single Failure An occurrence that results in the loss of capability of a component to perform its intended safety functions. Multiple failures resulting from a single occurrence are considered to be a single failure.

4.18 Source Term The magnitude, composition, form (physical and chemical), and mode of release (puff, intermittent, or continuous) of radioactive elements (including source isotope, fission, and activation products) released during a reactor accident.