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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
2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott 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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BREAKING NEWS: Trump issues executive orders to overhaul nuclear industry
The Trump administration issued four executive orders today aimed at boosting domestic nuclear deployment ahead of significant growth in projected energy demand in the coming decades.
During a live signing in the Oval Office, President Donald Trump called nuclear “a hot industry,” adding, “It’s a brilliant industry. [But] you’ve got to do it right. It’s become very safe and environmental.”
D. Squarer, A. T. Pieczynski, L. E. Hochreiter
Nuclear Science and Engineering | Volume 80 | Number 1 | January 1982 | Pages 2-13
Technical Paper | doi.org/10.13182/NSE82-A21399
Articles are hosted by Taylor and Francis Online.
In the worst hypothetical accident of a light water reactor (LWR), when all protection systems fail, the core could melt and be converted to a deep particulate bed as a result of molten-fuel-coolant interaction. The containment of such an accident depends on the coolability of the heat generating particulate bed. This paper summarizes published theoretical analyses that may predict bed dry out. In three of the analyses, the fluid flow in the heat generating particulate bed is considered to be laminar (Darcy's law), whereas in one study the fluid flow is solved for both the laminar and the turbulent flow regimes and is affected by capillary forces. The theoretical studies are compared with our recent data and with other recently published data covering a range of parameters that is expected in an LWR accident. An extension of the analysis and the experiments to a mixture of particle sizes is presented. The scaling of the dry out data to high pressures, which may be encountered during the course of an accident, is accomplished by multiplying the experimental bed dryout heat flux by the ratio of dry out flux at pressure to the dryout flux at atmospheric pressure. This ratio was calculated with the theoretical model, which agreed best with the experimental dryout data at atmospheric pressure. Based on the pressures and particle sizes expected in a pressurized water reactor core melt, it is concluded that stable (self-cooled) debris bed formation will occur if sufficient water is available.