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The deadline arrives: Checking in on the Reactor Pilot Program
On May 23, 2025, President Trump signed Executive Order 14301, “Reforming Nuclear Reactor Testing at the DOE,” which instructed the Department of Energy to create a Reactor Pilot Program (RPP)—a new system in which companies could pursue DOE authorization to build and test their first-of-a-kind nuclear technologies. EO 14301 set an ambitious goal for that program: three reactors achieving criticality by July 4, 2026.
C. H. Blanchard
Nuclear Science and Engineering | Volume 3 | Number 2 | February 1958 | Pages 161-170
Technical Paper | doi.org/10.13182/NSE58-A25458
Articles are hosted by Taylor and Francis Online.
The spatial moments ,, and are calculated exactly for all energies below the source energy, for a point, isotropic source in an infinite, homogeneous medium in which there is no absorption and in which the scatterers scatter like hydrogen but with a 1/υ cross section. For a monoenergetic source these moments are approximately consistent with a diffusion (Yukawa) radial distribution of the very low energy neutrons. Integration over a fission-like source spectrum, exp (—αE), gives moments consistent with a radial distribution of the very low energy neutrons of the form of a first collision density, r-2 exp (—r/λ), but with a mean free path λ approximately twice the mean free path at the average source energy. The results are compared with those given by the first collision approximation.