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Division Spotlight
Fuel Cycle & Waste Management
Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
Meeting Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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
DOE extends Centrus’s HALEU production contract by one year
Centrus Energy has announced that it has secured a contract extension from the Department of Energy to continue—for one year—its ongoing high-assay low-enriched uranium (HALEU) production at the American Centrifuge Plant in Piketon, Ohio, at an annual rate of 900 kilograms of HALEU UF6. According to Centrus, the extension is valued at about $110 million through June 30, 2026.
U. Hansen, R. Schulten, E. Teuchert
Nuclear Science and Engineering | Volume 47 | Number 1 | January 1972 | Pages 132-139
Technical paper | doi.org/10.13182/NSE72-A28426
Articles are hosted by Taylor and Francis Online.
A new and promising operating modus for the pebble-bed reactor has been investigated. Instead of circulating the fuel balls several times through the core they are moved only once slowly from the top to the bottom. Due to the increasing depletion toward the lower core area, there is a substantial axial tilt of the power density, and the downward flow of the cooling gas ensures for the system an optimal heat removal. The reduced power generation in the hot core area and the absence of hot spots enable achievement of a higher power density than in the known pebble-bed type and make possible a rise in the average gas outlet temperature up to 950°C. For a UO2-fueled reactor the life history is followed for several years by means of a two-dimensional calculational approach. Apart from the advantages in thermodynamics, the new system is marked by a very short and smooth running-in period, by a high sensibility of reactivity to control poison changes inside the upper reflector, and by an ideal accommodation of the burnup in the balls running with different flow speeds in different radial positions. The spatial distribution of the power density can be flexibly manipulated by changes in the fuel cycle speed, in fuel ball layout, or by the use of a higher feed enrichment in the outer core region. A brief parameter study and a discussion of technological aspects give an outline of the developing potential of that new type.