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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.
E. E. Lewis, R. Pfeffer
Nuclear Science and Engineering | Volume 27 | Number 3 | March 1967 | Pages 581-585
Technical Paper | doi.org/10.13182/NSE86-A17625
Articles are hosted by Taylor and Francis Online.
A formalism based on the Dirac chord method is extended from a previous paper to provide an analytical method for determining the properties of small fission-fragment sources of arbitrary convex geometry. The fragment escape probabilities, energy spectra, and energy deposition fractions are determined for spherical, slab, and cylindrical uranium-dioxide sources, using an energy-loss model that contains initial-energy spectra and range-energy relations for 42 fragment species. For comparison, calculations are also made, using two simplified energy-loss models. Finally, a method is given for generalizing the results to sources containing materials other than uranium dioxide.