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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.
C. L. Brown, L. E. Hansen, H. Toffer
Nuclear Science and Engineering | Volume 35 | Number 3 | March 1969 | Pages 358-363
Technical Paper | doi.org/10.13182/NSE69-A20014
Articles are hosted by Taylor and Francis Online.
Exponential and critical approach experiments have been performed to determine material buddings and extrapolation distances for several hexagonal lattice arrays of 2.1 wt% 235U enriched uranium tubes in light water. Tubes of two sizes were measured—2.33-in. o.d., 1.77-in. i.d.; and 1.38-in. o.d., 0.63-in. i.d. The arrays included clean lattices of uranium tubes; uranium tubes containing lithium aluminate target rods; uranium tubes with adjacent neutron absorbing columns; and two mixed lattices of 0.95 and 2.1 wt% enriched tubes—one with the 0.95 and 2.1 wt% tubes evenly distributed in the lattice, and the other with the 0.95 and 2.1 wt% tubes arranged in alternate rings. These experiments supplement data obtained in 1965 for 1.002, 1.25, and 1.95 wt% enriched uranium tubes. Critical parameters for these lattices, calculated with the HAMMER code, agree reasonably well with the measured results.
