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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.
Chang-Ho Lee, Thomas J. Downar
Nuclear Science and Engineering | Volume 146 | Number 2 | February 2004 | Pages 176-187
Technical Paper | doi.org/10.13182/NSE04-A2401
Articles are hosted by Taylor and Francis Online.
A hybrid nodal diffusion/simplified P3 (SP3) method was implemented within the framework of a one-node coarse-mesh finite difference formulation. The one-node formulation enables the use of various combinations of space, energy, and angular approximations within the framework of the one-node global/local solution approach. Spatial approximations include advanced nodal methods and fine-mesh finite difference methods. Energy approximations involve conventional two-group and multiple energy groups. Angular approximations contain both the diffusion and SP3 methods. Partial-moment boundary conditions are used to solve the one-node problems since they simplify the formulation of consistent interface conditions for the various methods. All directional moments are determined simultaneously to stabilize convergence of the one-node global/local solution approach. Results for a light water reactor mixed-oxide benchmark problem indicate that the hybrid application of the one-node-based nodal SP3 method developed here can provide substantial reductions in the computational time without compromising the accuracy of the solution.