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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.
Hiroshi Takahashi
Nuclear Science and Engineering | Volume 37 | Number 2 | August 1969 | Pages 198-215
Technical Paper | doi.org/10.13182/NSE69-A20679
Articles are hosted by Taylor and Francis Online.
The coherent neutron scattering from polycrystalline graphite is calculated using a sampling method with the Yoshimori-Kitano model and the Young-Koppel force constants. The calculations are compared with experimental results obtained by Carvalho, Eremeev et al., and Whittemore and it is shown that the agreement between the calculations and the experimental results is very good. For Carvalho's experiment, which corrects for multiple scattering, the agreement is good for the range of small momentum transfer (α) while for the experiments of Eremeev et al. the agreement is best for the range of intermediate α. A comparison of the dispersion relation, polarization vector and the dynamical structure factor for the Yoshimori-Kitano model and the Young-Koppel model indicates that the difference in the scattering laws is mainly due to the difference in the dispersion relations. A code called “ONE-PHONON” which uses a sampling method to calculate the scattering law is described. It is suggested that the measurement of the scattering law for each mode in pyrolitic graphite will give valuable information about the lattice dynamics of graphite.