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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.
K. D. Lathrop
Nuclear Science and Engineering | Volume 24 | Number 4 | April 1966 | Pages 381-388
Technical Paper | doi.org/10.13182/NSE66-A16408
Articles are hosted by Taylor and Francis Online.
To permit numerical solution of photon transport problems by the method of discrete ordinates, an anisotropic scattering approximation and a multigroup cross-section preparation recipe are selected. The incorporation of the anisotropic scattering approximation in a discrete-ordinates transport-theory code is described. Results of discrete-ordinates calculations are compared to Monte Carlo and moments-methods computations in three test problems. Flux values and leakage percentages in the different methods of solution are found to be in excellent agreement, even when a relatively low-order (four or six terms of a Legendre polynomial expansion) anisotropic scattering approximation is used in the discrete-ordinates method. In the test problems considered, the discrete-ordinates method is (computationally) nearly an order of magnitude faster than the other methods.