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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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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Powering the future: How the DOE is fueling nuclear fuel cycle research and development
As global interest in nuclear energy surges, the United States must remain at the forefront of research and development to ensure national energy security, advance nuclear technologies, and promote international cooperation on safety and nonproliferation. A crucial step in achieving this is analyzing how funding and resources are allocated to better understand how to direct future research and development. The Department of Energy has spearheaded this effort by funding hundreds of research projects across the country through the Nuclear Energy University Program (NEUP). This initiative has empowered dozens of universities to collaborate toward a nuclear-friendly future.
Tadashi Yoshida
Nuclear Science and Engineering | Volume 72 | Number 3 | December 1979 | Pages 361-365
Technical Note | doi.org/10.13182/NSE79-A20393
Articles are hosted by Taylor and Francis Online.
A method is presented for determining by numerical integration a diffusion coefficient, Dz, applicable to the axial direction of a control rod follower region in a sodium-cooled fast reactor. By comparing criticality values from transport and diffusion theory for a simplified reactor model, we are able to show that this Dz applies well to the followers from the viewpoint of the calculated criticality factor, keff. By use of the same model, an inter comparison is also made between the present and other definitions of Dz. By using the present Dz, as a conclusion, we show that the currently used D (= 1/3Σ) for control rod followers leads to an underestimation of keff by ∼0.3% for a typical 300-MW(electric) class liquid-metal fast breeder reactor with one-third of the control rods inserted, which may increase to 0.4 to 0.5% for a case where all control rods are withdrawn.