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Mathematics & Computation
Division members promote the advancement of mathematical and computational methods for solving problems arising in all disciplines encompassed by the Society. They place particular emphasis on numerical techniques for efficient computer applications to aid in the dissemination, integration, and proper use of computer codes, including preparation of computational benchmark and development of standards for computing practices, and to encourage the development on new computer codes and broaden their use.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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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
First astatine-labeled compound shipped in the U.S.
The Department of Energy’s National Isotope Development Center (NIDC) on March 31 announced the successful long-distance shipment in the United States of a biologically active compound labeled with the medical radioisotope astatine-211 (At-211). Because previous shipments have included only the “bare” isotope, the NIDC has described the development as “unleashing medical innovation.”
Jack Chernick
Nuclear Science and Engineering | Volume 1 | Number 2 | May 1956 | Pages 135-155
Technical Paper | doi.org/10.13182/NSE56-A17518
Articles are hosted by Taylor and Francis Online.
The nuclear properties and potentialities of small liquid metal fueled reactors (LMFR) are presented. Plutonium is discussed as an alternate fuel to uranium isotopes, lead as alternate carrier to bismuth, and beryllium as alternate moderator to graphite. Breeding potentialities of U233 and Pu239 fueled liquid metal systems are discussed. It is shown that non-breeder cores can be reduced to about 1 to 4 ft in diameter, depending on fuel concentration and core and reflector compositions. Internal versus external cooling and internal versus external moderation of the small LMFR are compared. Internally moderated reactors have a more complex core but require less fissionable material. For LMFR cores externally moderated by graphite, the critical mass requirements are found to be relatively constant over a wide range of fuel concentrations with a minimum of about 10 kg for U233 fuel. For small LMFR cores, heat transfer rather than heat transport is the only bar to extremely high specific power in power applications and to high neutron flux in research applications. Externally cooled reactors, coupled to conventional heat exchangers require a large external holdup of the liquid metal, thus putting a premium on low fuel concentrations. Internally cooled LMFR's with graphite (or beryllium) moderation and heat exchange require advances in present technology. Sodium is an attractive coolant for an internally cooled, externally moderated version of the LMFR with slurry type fuel elements. It is pointed out that, for research applications, the flux level achievable in a thermal reactor with fixed power output has about reached its practical limit. This is not the situation for intermediate energy reactors. In particular, it is shown that an intermediate energy LMFR can achieve an average core flux of 1015 neutrons/cm2-sec at 10 Mw power output. Finally, integral experiments and neutron cross sections needed for firm estimates of the conversion ratios and critical mass requirements of LMFR systems, especially for weakly moderated systems, are discussed.
