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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.
Greg Wojtowicz, James Paul Holloway
Nuclear Science and Engineering | Volume 121 | Number 1 | September 1995 | Pages 89-102
Technical Paper | doi.org/10.13182/NSE95-A24131
Articles are hosted by Taylor and Francis Online.
A variational coarse-mesh technique is developed for the solution of the multigroup neutron transport equation in one-dimensional reactor lattices. In contrast to conventional nodal lattice applications that discretize diffusion theory and use node homogenized cross sections, the methods used here retain the spatial dependence of the cross sections and instead employ an alternative flux representation, a slowly modulated pin cell flux, that allows the neutron transport equation to be cast into a form whose solution has a relatively slow spatial and angular variation and that can be accurately described with relatively few variables. This alternative flux representation and the stationary property of a variational principle define a class of coarse-mesh discretizations of transport theory that are capable of achieving order-of-magnitude reductions of eigenvalue and pointwise scalar flux errors compared with diffusion theory while retaining the relatively low cost of diffusion theory.