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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.
Nam Zin Cho, Jae Man Noh
Nuclear Science and Engineering | Volume 121 | Number 2 | October 1995 | Pages 245-253
Technical Paper | doi.org/10.13182/NSE95-A28561
Articles are hosted by Taylor and Francis Online.
A new hexagonal nodal method that directly solves the multidimensional diffusion equation without the transverse integration procedure is described. The new method expands the homogeneous flux distributions within a node in nonseparable analytic basis functions satisfying the neutron diffusion equations at any point of the node. Because the new method does not use the transverse integration, it does not suffer from the need of approximating the transverse leakage shape and the nonphysical singular terms occurring in hexagonal nodes. And, because of the use of analytical basis functions and the corner-point flux included in the nodal coupling equations, the method accurately models large localized flux gradients in the vicinity of nodal corner points as well as nodal interfaces. The new method was tested on two hexagonal benchmark problems consisting of uranium-oxide and mixed-oxide fuel assemblies to demonstrate its accuracy and applicability to realistic problems. The results show that the new method accurately predicts the nodal flux distribution and the core multiplication factor.