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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.
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August 11–11, 2020
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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 ongoing effort to convert the world’s research reactors
The Ghana Research Reactor-1, located in Accra, Ghana, was converted from HEU fuel to LEU in 2017. Photo: Argonne National Laboratory
In late 2018, Nigeria’s sole operating nuclear research reactor, NIRR-1, switched to a safer uranium fuel. Coming just 18 months on the heels of a celebrated conversion in Ghana, the NIRR-1 reboot passed without much fanfare. However, the switch marked an important global milestone: NIRR-1 was the last of Africa’s 11 operating research reactors to run on high-enriched uranium fuel.
The 40-year effort to make research reactors safer and more secure by replacing HEU fuel with low-enriched uranium is marked by a succession of quiet but immeasurably significant milestones like these. Before Africa, a team of engineers from many organizations, including the U.S. Department of Energy’s Argonne National Laboratory, concluded its conversion work in South America and Australia. Worldwide, 71 reactors in nearly 40 countries have undergone conversions to LEU, defined as less than 20 percent uranium-235. Another 31 research reactors have been permanently shut down.
Z. M. Smith, S. K. Loyalka
Nuclear Science and Engineering | Volume 176 | Number 2 | February 2014 | Pages 154-166
Technical Paper | dx.doi.org/10.13182/NSE12-107
Articles are hosted by Taylor and Francis Online.
In the dry environments of high-temperature gas reactors, aerosols and dust particles can be highly nonspherical and even chainlike agglomerates, and are highly charged. To elucidate the role of both shape and charge on particle dynamics, we have explored numerical solutions of the Poisson equation for arbitrary geometries. In this paper, we describe the general computational framework, and report results for condensation/evaporation for several different cases, including chainlike agglomerates. We find that the shape factor based on the volume equivalent sphere approximation underestimates the actual condensation rate on the agglomerate, in addition to not accounting for the local condensation rates.
