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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.
S. Iijima
Nuclear Science and Engineering | Volume 17 | Number 1 | September 1963 | Pages 42-46
Technical Paper | doi.org/10.13182/NSE63-A17208
Articles are hosted by Taylor and Francis Online.
The origin of the so-called resonance disadvantage factor was investigated from the point of view of (1) the incomplete recovery of the flux at off-resonance energies and (2) the decrease in the surface flux due to the failure of the narrow resonance approximation in the moderator. The flux recovery was studied by age theory for a typical rectangular lattice of the uranium in graphite and the effect upon the absorption by the 6.7-ev resonance of U238 was found to be of the order of magnitude of 2% or less. The second problem was studied by solving for the space-energy flux by iteration. Sizeable corrections were found to be necessary for the low-lying resonances of U238 in graphite. An approximate analytical formula was presented for this correction.
