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Conference Spotlight
2025 ANS Winter Conference & Expo
November 8–12, 2025
Washington, DC|Washington Hilton
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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.
L. J. Esch
Nuclear Science and Engineering | Volume 16 | Number 2 | June 1963 | Pages 196-201
Technical Paper | doi.org/10.13182/NSE63-A26499
Articles are hosted by Taylor and Francis Online.
The neutron diffusion length in paraffin has been measured by a static technique in the temperature range from 60°C to 130°C. The neutron transport cross section was abstracted from the measured diffusion length. A semiempirical prescription describing the temperature dependence of the neutron transport cross section in paraffin and polyethylene has been derived. The derivation is based on that of the Radkowsky prescription for water. A calculation of the transport cross section in paraffin and polyethylene has been carried out in the temperature range from 20°C to 125°C. The measured transport cross section in paraffin has been compared with that predicted by the prescription. The values agree within 3%. A 14% difference between the values for paraffin and those for water gives credence to the assumption that calculations of the characteristics of plastic moderated critical assemblies can be improved by the use of the proper prescription.
