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Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 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
Radiant to build first microreactor at Tenn. Manhattan Project site
Radiant Industries will build its first portable nuclear reactor at the site of the Manhattan Project in Oak Ridge, Tenn.
The land for Radiant’s new factory includes portions of the K-27 and K-29 Manhattan Project sites. The company plans to test Kaleidos, a 1-MW nuclear microreactor, in 2026, with first deployments expected soon after.
Keisuke Kobayashi, Kenji Nishihara
Nuclear Science and Engineering | Volume 136 | Number 2 | October 2000 | Pages 272-281
Technical Paper | doi.org/10.13182/NSE00-A2158
Articles are hosted by Taylor and Francis Online.
Using an importance function describing the capability of a system for producing fission neutrons, a new definition of the subcriticality is proposed, which has the physical meaning of a multiplication factor in a real subcritical system with external sources. This multiplication factor ks, which expresses the number of fission neutrons produced by a fission neutron in a steady state, is different from the usual criticality factor or the effective multiplication factor keff, since the former is calculated from the inhomogeneous equation with external source, whereas the latter is calculated from the homogeneous criticality equation without external source.
