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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.
Tengfei Zhang, E. E. Lewis, M. A. Smith, W. S. Yang, Hongchun Wu
Nuclear Science and Engineering | Volume 186 | Number 2 | May 2017 | Pages 120-133
Technical Paper | doi.org/10.1080/00295639.2016.1273023
Articles are hosted by Taylor and Francis Online.
A two-dimensional/one-dimensional (2D/1D) variational nodal approach is presented for pressurized water reactor core calculations without fuel-moderator homogenization. A 2D/1D approximation to the within-group neutron transport equation is derived and converted to an even-parity form. The corresponding nodal functional is presented and discretized to obtain response matrix equations. Within the nodes, finite elements in the x-y plane and orthogonal functions in z are used to approximate the spatial flux distribution. On the radial interfaces, orthogonal polynomials are employed; on the axial interfaces, piecewise constants corresponding to the finite elements eliminate the interface homogenization that has been a challenge for method of characteristics (MOC)–based 2D/1D approximations. The angular discretization utilizes an even-parity integral method within the nodes, and low-order spherical harmonics (PN) on the axial interfaces. The x-y surfaces are treated with high-order PN combined with quasi-reflected interface conditions. The method is applied to the C5G7 benchmark problems and compared to Monte Carlo reference calculations.