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OSTP memo guides space nuclear plan
A White House Office of Science and Technology Policy (OSTP) memorandum released on Tuesday guides NASA, the Department of Energy, and the Department of Defense on their roles in deploying near-term space nuclear power.
This follows a series of NASA announcements last month—driven by the executive order “Ensuring American Space Superiority,” issued by Trump in December—including an ambitious timeline for establishing a moon base, which would rely on fission surface power (FSP) to survive the long lunar night at the moon’s south pole, and plans for a nuclear electric propulsion (NEP) rocket to be launched in 2028.
Anil K. Prinja, Patrick F. O’Rourke, Scott D. Ramsey
Nuclear Science and Engineering | Volume 199 | Number 1 | April 2025 | Pages S249-S263
Research Article | doi.org/10.1080/00295639.2024.2340167
Articles are hosted by Taylor and Francis Online.
Neutron chain survival and ultimate divergence in coupled multiplying assemblies, linked by intercepted leaking neutrons, are considered. Nonlinear equations are formulated for the dynamic probability of survival and static probability of initiation (POI) with assembly intercept fractions computed using a view factor model. Numerical solutions are obtained for up to four coupled assemblies, revealing a sensitive dependence on interassembly coupling strength. The results indicate that a chain will not diverge with certainty in a subcritical or critical system but that divergence will occur with some probability POI > 0 that increases with coupling strength. Additionally, at keff = 1, the stable subcritical solution branch is observed to bifurcate into two branches, one of which is shown through linear stability analysis to be unstable.