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Become a knowledge manager at UWC 2024
The American Nuclear Society is now accepting applications for knowledge managers to work during the 2024 Utility Working Conference and Vendor Technology Expo. This year’s UWC, “Nuclear Momentum: Advancing Our Clean Energy Future,” will be held August 4–7, 2024, at the JW Marriott Marco Island Beach Resort on Marco Island, Fla.=
William B. Terney
Nuclear Science and Engineering | Volume 57 | Number 3 | July 1975 | Pages 239-245
Technical Note | doi.org/10.13182/NSE75-A26755
Articles are hosted by Taylor and Francis Online.
In the newer, larger pressurized-water reactor cores, the calculated power distributions are fairly sensitive to the number of neutron groups used and to the treatment of the reflector cross sections. Comparisons between transport and diffusion calculations show that the latter substantially underpredict the reflector albedos in the fast (top) group and that the power distribution is shifted toward the core center when compared to 4-group transport theory results. When the fast-neutron diffusion coefficients are altered to make the transport- and diffusion-theory albedos agree, the power distributions are also brought into agreement. An expression for the fast-neutron diffusion coefficients in reflector regions has been derived such that the diffusion calculation reproduces the albedo obtained from a transport solution. In addition, a correction factor for mesh effects applicable to coarse mesh problems is presented. The use of the formalism gives the correct albedos and improved power distributions.