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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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The 2025 ANS election results are in!
Spring marks the passing of the torch for American Nuclear Society leadership. During this election cycle, ANS members voted for the newest vice president/president-elect, treasurer, and six board of director positions (four U.S., one non-U.S., one student). New professional division leadership was also decided on in this election, which opened February 25 and closed April 15. About 21 percent of eligible members of the Society voted—a similar turnout to last year.
Q. Lv, H. C. Lin, S. Shi, X. Sun, R. N. Christensen, T. E. Blue, G. Yoder, D. Wilson, P. Sabharwall
Nuclear Technology | Volume 196 | Number 2 | November 2016 | Pages 319-337
Technical Paper | doi.org/10.13182/NT16-41
Articles are hosted by Taylor and Francis Online.
The Direct Reactor Auxiliary Cooling System (DRACS) is a passive decay heat removal system proposed for the Fluoride salt–cooled High-temperature Reactor (FHR) that combines coated particle fuel and a graphite moderator with a liquid fluoride salt as the coolant. The DRACS features three coupled natural circulation/convection loops, relying completely on buoyancy as the driving force. These loops are coupled through two heat exchangers, namely, the DRACS heat exchanger (DHX) and the natural draft heat exchanger (NDHX). To experimentally investigate the thermal performance of the DRACS, a scaled-down low-temperature DRACS test facility (LTDF) has been constructed. The design of the LTDF is obtained through a detailed scaling analysis based on a 200-kW prototypic DRACS design developed at The Ohio State University. The LTDF has a nominal power capacity of 6 kW. It employs water pressurized at 1.0 MPa as the primary coolant, water near the atmospheric pressure as the secondary coolant, and ambient air as the ultimate heat sink. Three accident scenarios simulated in the LTDF are discussed in this paper. In the first scenario, startup of the DRACS system from a cold state is simulated with no initial primary coolant flow. In the second scenario, a reactor coolant pump trip process is studied, during which a flow reversal phenomenon in the DRACS primary loop occurs. In the third scenario, the pump trip process is studied with a simulated intermediate heat exchanger in operation during the simulated core normal operation. In all scenarios, natural circulation flows are developed as the transients approach their quasi steady states, demonstrating the functionality of the DRACS. The accident scenarios in the prototypic FHR design corresponding to the simulated ones in the LTDF are also predicted by following a scaling-up process. The predictions show that at any time during the simulated transient, the salt temperatures will be higher than their melting temperatures and that therefore there will be no issue of salt freezing in the three projected accident scenarios. However, the scaled-up primary salt temperatures indicate that the prototypic DHX may have been undersized and may need to be redesigned.