This digital version of the handbook provides a routinely-updated and more navigable version of information and best practices associated with NASA’s nuclear flight safety activities that fall within NASA’s domain. It is managed by a small content management group based on observations and feedback about the Handbook’s content and is intended for internal use. The updated content will be periodically rolled in to a new/approved external version of the Handbook.

This handbook provides information and best practices associated with NASA’s nuclear flight safety activities that fall within NASA’s domain (as opposed to that of other Federal authorities). It applies specifically to space nuclear systems, which include radioisotope power systems and fission reactors. Its purpose is to facilitate a repeatable and robust process that promotes clear and effective interfaces between activities and stakeholders focused on meeting nuclear flight safety requirements within the context of NASA’s broader nuclear-related activities and interfaces.

This memo affirms that a categorical relief threshold corresponding to an A2 mission multiple of 0.001 is suitable for use in accordance with the definition of this process in NPR 8715.26, based on quantitative assessments performed since the initial January 2021 categorical relief memo.

This course is designed to provide NASA personnel with an overview of Nuclear Flight Safety and to increase knowledge across the programmatic, mission support and Technical Authority, with a focus on Safety and Mission Assurance personnel. 

Course Number:SMA-STL-WBT-403

Length: 2 hours

Audience: This course is intended for NASA Chief Safety and Mission Assurance Officers assigned to programs or projects using radioactive material, system and safety professionals, Reliability and Maintainability personnel, others who ensure Nuclear Flight Safety, the NASA Headquarters and local center Safety and Mission Assurance community, and program and project managers.

NPR 8715.26 addresses roles, responsibilities and requirements related to implementation of NASA’s Nuclear Flight Safety Program. It follows the 2019 National Security Presidential Memorandum-20 overhaul of the federal process for nuclear launch authorization of space nuclear systems and the 2020 release of  Space Policy Directive-6, which established a national strategy to ensure the development and use of space nuclear power and propulsion systems, “when appropriate to enable and achieve the scientific, exploration, national security, and commercial objectives of the United States.” The NPR also brings NASA policy into alignment with present day practices. It replaced NPR 8715.3D, Chapter 6.

This document describes the Interagency Nuclear Safety Review Board's (INSRB) intent and functionality at a more detailed level. It is generally non-binding, but it sets expectations for how the board and INSRB Review Groups (IRGs) are likely to behave. It also addresses clarifications in governing policies when those are identified. Its primary function is to document expectations and boundaries for how INSRB will conduct business and how INSRB expects that mission owners and product recipients will interface with the board and IRGs, so as to promote openness and effectiveness in its activities. Revision 2 (January 2023) addresses limited feedback received since Revision 1 was issued; incorporates the recommendations of small group activities focused on upstream technical peer review interfaces and how the INSRB would be involved between the time of launch authorization and launch; adds INSRB “intents” to the document preamble; incorporates conforming changes with the 2022 INSRB Charter revision; and adds an IRG empanelment checklist.

Invocation pending the 2021 update to the Nuclear Flight Safety NASA Procedural Requirements (NPR)

This categorical relief covers launches and reentries (specifically referring to a planned return to Earth), which have a total A2 mission multiple (considering all radioactive materials onboard) of less than 0.1% (i.e., activity less than 0.001×A2), and which would otherwise require concurrence through the Office of Safety and Mission Assurance. The A2 mission multiple is to be calculated in accordance with the Nuclear Flight Safety NPR.

This charter outlines high-level governance aspects of the Interagency Nuclear Safety Review Board (INSRB), which was created in February 2020 in response to National Security Presidential Memorandum (NSPM)-20. The INSRB serves as the interagency nuclear safety review entity for government-sponsored launches of space nuclear systems in Tier II and Tier III, as defined in NSPM-20, and for commercial launches of space nuclear systems when requested by the secretary of transportation. The INSRB is administered by NASA’s Office of Safety and Mission Assurance.

This handbook is the companion document to NPR 7120.5, NASA Space Flight Program and Project Management Requirements, and represents the accumulation of knowledge NASA gleaned on managing program and projects coming out of NASA’s human, robotic and scientific missions of the last decade.