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Division Spotlight
Accelerator Applications
The division was organized to promote the advancement of knowledge of the use of particle accelerator technologies for nuclear and other applications. It focuses on production of neutrons and other particles, utilization of these particles for scientific or industrial purposes, such as the production or destruction of radionuclides significant to energy, medicine, defense or other endeavors, as well as imaging and diagnostics.
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.”
Miriam A. Kreher, Kord Smith, Benoit Forget
Nuclear Science and Engineering | Volume 196 | Number 4 | April 2022 | Pages 409-432
Technical Paper | doi.org/10.1080/00295639.2021.1980363
Articles are hosted by Taylor and Francis Online.
Transient simulations of nuclear systems face the computational challenge of resolving both space and time during reactivity changes. A common strategy for tackling this issue is to split the neutron flux into shape and amplitude functions. This split can be solved with high-order/low-order methods. In this paper, a direct comparison of commonly used approximations (e.g., adiabatic, omega, alpha eigenvalue, frequency transform, quasi-static) is performed on the two-dimensional Laboratorium für Reaktorregelung und Anlagensicherung (2D-LRA) benchmark problem using a diffusion solver as the high-order solver and point kinetics as the low-order solver. Additionally, a novel hybrid omega/alpha-eigenvalue solver that incorporates frequencies to model delayed neutrons is introduced. The goal of the comparison is to quantify the performance of each method on a common problem to help inform promising pathways for costly high-fidelity solvers. Overall, we show that exponential frequency approximations are an effective strategy for increasing the accuracy of transient simulations with no added cost. Root-mean-square error of the power distribution at the peak of the transient was consistently decreased by 20% by including frequencies. In particular, the hybrid omega/alpha-eigenvalue method shows improvement over existing eigenvalue solvers as a high-order method. However, in our implementation, the cost of solving for the alpha eigenmode is too costly to recommend over the omega method. While time-differencing schemes are more accurate, we believe the eigenvalue methods are more adaptable to further applications in Monte Carlo transients. Furthermore, they required fewer outer time steps, significantly reducing the computational cost.