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Conference Spotlight
2025 ANS Winter Conference & Expo
November 8–12, 2025
Washington, DC|Washington Hilton
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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Latest News
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.
W. Rothenstein J. Helholtz
Nuclear Science and Engineering | Volume 14 | Number 3 | November 1962 | Pages 239-243
doi.org/10.13182/NSE62-A26212
Articles are hosted by Taylor and Francis Online.
The Dancoff correction for fuel rods surrounded by air gaps arranged in a hexagonal lattice in a moderator is calculated as a function of the rod radius measured in units of moderator mean free paths, the moderator to fuel volume ratio, and the width of the air gap relative to the radius of the rod. It is found that the Dancoff correction increases with the width of the air gap, when the other parameters are kept constant. This leads to a decrease of the mean chord length in the moderator and consequently a slight increase of the resonance escape probability, whose magnitude may be estimated from the simplest formula for the effective resonance integral.
