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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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2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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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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Wyoming as a hub for the nuclear supply chain?
A 60-year-old Wyoming industrial machinery company has joined forces with nuclear innovator BWX Technologies to build and deploy 50-megawatt microreactors in America’s heartland over the coming years to provide carbon-free heat and power for industrial users.
Doonyapong Wongsawaeng, Donald R. Olander
Nuclear Technology | Volume 146 | Number 3 | June 2004 | Pages 211-220
Technical Paper | Fuel Cycle and Management | doi.org/10.13182/NT04-A3500
Articles are hosted by Taylor and Francis Online.
In light water reactors, a helium-filled gap between the fuel and the cladding accommodates fuel swelling and cladding creepdown. However, the low thermal conductivity of helium results in a large T over the gap before closure occurs. To remedy this situation, Wright et al. proposed the use of a liquid metal (LM) bond in the fuel-cladding gap. The LM (33 wt% each of lead, tin, and bismuth) was chosen for its low melting point (~120°C), its lack of chemical reactivity with UO2 and water, and its high thermal conductivity (~100 times that of He). The thermal resistance of the LM-bonded gap is nil.Prior to closure of a helium-bonded gap, the centerline fuel temperature can be hundreds of degrees hotter than that with an LM-bonded gap at the same linear heat rating. Since the diffusion of fission gas atoms depends strongly upon temperature, it is expected that with the high thermal conductivity pellet-cladding gap, the incubation time to fission gas release should be considerably delayed. A modified Booth Sphere model, which takes into account re-solution, is adopted. The amount of fission gas atoms collected at the grain boundary is calculated using realistic time-temperature histories taken from a recent U.S. Nuclear Regulatory Commission review. The saturation value of gas at the grain boundary proposed by Dowling to fission gas release is adopted. The results show that although the temperature in the LM-bonded case is substantially lower than the He-filled case when the gap is open, the temperatures in the two cases equalize when the gap vanishes. Correspondingly, the two cases exhibit a comparable amount of fission gas at the grain boundary. Calculated differences between the times to saturation with LM and He in the gap are as high as ~1 yr and as low as 1 to 2 days.