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Division Spotlight
Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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
El Salvador: Looking to nuclear
In 2022, El Salvador’s leadership decided to expand its modest, mostly hydro- and geothermal-based electricity system, which is supported by expensive imported natural gas and diesel generation. They chose to use advanced nuclear reactors, preferably fueled by thorium-based fuels, to power their civilian efforts. The choice of thorium was made to inform the world that the reactor program was for civilian purposes only, and so they chose a fuel that was plentiful, easy to source and work with, and not a proliferation risk.
Cihang Lu, Zeyun Wu
Nuclear Technology | Volume 208 | Number 10 | October 2022 | Pages 1577-1590
Technical Paper | doi.org/10.1080/00295450.2022.2049966
Articles are hosted by Taylor and Francis Online.
Equilibrium state generation for the pebble bed reactor (PBR) is challenging due to the need to simultaneously account for both pebble movement and changes in fuel compositions. Multigroup diffusion codes have been historically employed to generate the equilibrium state and perform conventional neutronics calculations for PBRs, while neutron cross-section generation has been challenging due to the double heterogeneity of PBRs. Thanks to the capability to treat the double heterogeneity naturally, continuous-energy Monte Carlo (MC) methods are more suitable for detailed PBR analysis, but at the cost of significantly higher computing power.
This paper presents a new Methodology to Efficiently Estimate the Equilibrium State of a PBR (MEEES-PBR) to generate equilibrium-state MC models for PBRs at lower computational expense. The MEEES-PBR is expected to contribute to the future development of PBR designs by accelerating the efforts in core designs and parametric studies. The theory of the MEEES-PBR is introduced in detail in this paper, and the procedure is demonstrated via an example application to the 165-MW(thermal) Xe-100 design. The computational cost and the accuracy of the MEEES-PBR are discussed to prove its viability.