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Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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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Sellafield awards $3.86B in infrastructure contracts to three companies
Sellafield Ltd., the site license company overseeing the decommissioning of the U.K.’s Sellafield nuclear site in Cumbria, England, announced the award of £2.9 billion (about $3.86 billion) in infrastructure support contracts to the companies of Morgan Sindall Infrastructure, Costain, and HOCHTIEF (UK) Construction.
D. J. Donahue, D. D. Lanning, R. A. Bennett, R. E. Heineman
Nuclear Science and Engineering | Volume 4 | Number 3 | September 1958 | Pages 297-321
Technical Paper | doi.org/10.13182/NSE58-A25530
Articles are hosted by Taylor and Francis Online.
The PCTR is a seven-foot cube of graphite with a large cavity, 2 x 2 x 3 ft, located at its center. It is made critical by enriched uranium which is distributed on the boundary of the central cavity. One end of the assembly, 2 x 7 x 7 ft, is mounted on a movable cart, and can be moved away from the reactor proper allowing access to the central test region. The infinite medium, thermal neutron multiplication factor, k∞, of a multiplying material is obtained by determining the amount of thermal absorber, which, when inserted with the multiplying material into the central region of the PCTR, will change neither the reactivity of the assembly nor the energy distribution of neutrons in it. The design of the reactor and the method used for determining this absorber mass are discussed and results for two graphite-natural uranium lattices are presented.