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Division Spotlight
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
Meeting Spotlight
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver Downtown
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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Fusion Science and Technology
May 2025
Latest News
Argonne’s METL gears up to test more sodium fast reactor components
Argonne National Laboratory has successfully swapped out an aging cold trap in the sodium test loop called METL (Mechanisms Engineering Test Loop), the Department of Energy announced April 23. The upgrade is the first of its kind in the United States in more than 30 years, according to the DOE, and will help test components and operations for the sodium-cooled fast reactors being developed now.
Dennis L. Youchison, Alex M. Melin, Arnold Lumsdaine, Charles R. Schaich, Gregory R. Hanson
Fusion Science and Technology | Volume 72 | Number 3 | October 2017 | Pages 324-330
Technical Paper | doi.org/10.1080/15361055.2017.1333855
Articles are hosted by Taylor and Francis Online.
The electron cyclotron heating system (ECH) on ITER uses 24 evacuated microwave transmission lines carrying up to 1.4 MW of power each at 170 GHz to provide resonance heating of electrons in the ITER plasma and to enable plasma current drive. A critically important component in this system is the microwave switch that allows the microwaves to be directed from the gyrotrons to either dummy loads or between launchers in the upper and equatorial ports of the ITER tokamak while maintaining the vacuum integrity of the transmission lines. A moveable, water-cooled CuCrZr mirror is used to redirect the microwave transmission between two orthogonal waveguides.
In this article we describe the optimized design of the mirror cooling passages produced by computational fluid dynamics analysis using ANSYS CFX with k-ε and k-ω shear stress transport turbulence models, and verify that the design parameters for mass flow rate, inlet temperature and pressure are adequate for good thermomechanical performance. Non-uniform heating of the mirror face from the incident microwaves induces deflections that should be less than 25 microns to meet the integrated transmission line efficiency specification. In the current 1.4 MW switch design, 0.03 kg/s of 36°C water at 10 bar inlet pressure can remove the 2660 W of ohmic heating in the mirror produced by the elliptical polarization power and maintain the surface temperature below 150°C. The water delta-T is 21°C with a 0.5 bar pressure drop in the mirror. The maximum predicted displacement in the center of the mirror face is less than 25 μm.