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Conference Spotlight
2025 ANS Winter Conference & Expo
November 8–12, 2025
Washington, DC|Washington Hilton
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Japan gets new U for enrichment as global power and fuel plans grow
President Trump is in Japan today, with a visit with new Prime Minister Sanae Takaichi on the agenda. Takaichi, who took office just last week as Japan’s first female prime minister, has already spoken in favor of nuclear energy and of accelerating the restart of Japan’s long-shuttered power reactors, as Reuters and others have reported. Much of the uranium to power those reactors will be enriched at Japan’s lone enrichment facility—part of Japan Nuclear Fuel Ltd.’s Rokkasho fuel complex—which accepted its first delivery of fresh uranium hexafluoride (UF₆) in 11 years earlier this month.
Rashmi C. Desai, Mark Nelkin
Nuclear Science and Engineering | Volume 24 | Number 2 | February 1966 | Pages 142-152
Technical Paper | doi.org/10.13182/NSE66-A18299
Articles are hosted by Taylor and Francis Online.
The time-dependent moments equations derived from the linearized Boltzmann equation are solved for the case of an infinite nonabsorbing medium of hard spheres. The distribution function at zero time is chosen to be Maxwellian at origin and zero elsewhere. The solutions can be applied to neutron diffusion in monatomic hydrogen and to the motion of atoms in a dilute monatomic gas. In the latter case, the solutions give the spatial moments of Van Hove's self-correlation function Gs(,t). Non-Gaussian corrections to Gs(, t) are studied. It is found that these corrections are very sensitive to the type of anisotropy of the scattering kernel. Various approximations (including synthetic kernel) of the exact kernel for a hard sphere gas are considered. The non-Gaussian corrections obtained from approximate kernels are compared with those obtained from the exact kernel. In particular, a recently published kinetic model calculation, using a separable isotropic kernel with l/v scattering cross section, overestimates the non-Gaussian corrections by a factor of almost 4.