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Division Spotlight
Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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
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.”
Alain Hébert
Nuclear Science and Engineering | Volume 151 | Number 1 | September 2005 | Pages 1-24
Technical Paper | doi.org/10.13182/NSE151-1-24
Articles are hosted by Taylor and Francis Online.
Improvement of the lattice code component related to resonance self-shielding calculations is described. The proposed self-shielding model is based on a subgroup flux equation with probability tables, as implemented in the CALENDF approach of P. Ribon. A new type of correlated two-dimensional probability table is introduced for the representation of the slowing-down effect in the resolved energy domain. The resulting formalism makes possible a better representation of distributed self-shielding effects.A new numerical scheme is also proposed to represent the mutual shielding effect of overlapping resonances between different isotopes in the context of the Ribon subgroup equations. The interference effects between two resonant isotopes are represented by a correlated weight matrix also computed using a CALENDF approach. The model was designed with the primary goal of allowing the straightforward replacement of legacy self-shielding components in typical lattice codes to gain improved accuracy without any noticeable increase in CPU resources.Finally, a validation is presented where the absorption rates are compared with exact values obtained using a fine-group elastic slowing-down calculation in the resolved energy domain. Other results, relative to Rowland's pin-cell benchmarks, are also presented. The need to represent mutual shielding effects, at least for mixed-oxide fuel is demonstrated.