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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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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. P. Poenitz
Nuclear Science and Engineering | Volume 40 | Number 3 | June 1970 | Pages 383-388
Technical Paper | doi.org/10.13182/NSE70-A20189
Articles are hosted by Taylor and Francis Online.
The ratios σγ(238U)/σ/(235U), σγ(238U)/σγ(239Pu), and σf (239Pu)/σf (235U) have been measured in the energy range 130 to 1400 keV. The activation technique was used to determine the capture rate in 238U. The 278 keV γ ray emitted in the decay of 239Np was detected by means of a Ge(Li) detector. The counting efficiencies have been absolutely determined for the measurement of σγ(238U)/σf(239Pu). For the determination of the ratio σγ(238U)/σf(235U) the counting efficiencies have been eliminated by a measurement of the ratio at thermal-neutron energies. The ratio σf(239Pu)/σf(235U) has been measured in a back-to-back gas scintillation counter using the time-of-flight method for background suppression. The measurements resulted in an overdetermination of two unknown quantities by three measured values. The fitted values derived from the collective results were in good agreement with the individual measured ratios.
