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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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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Deep Space: The new frontier of radiation controls
In commercial nuclear power, there has always been a deliberate tension between the regulator and the utility owner. The regulator fundamentally exists to protect the worker, and the utility, to make a profit. It is a win-win balance.
From the U.S. nuclear industry has emerged a brilliantly successful occupational nuclear safety record—largely the result of an ALARA (as low as reasonably achievable) process that has driven exposure rates down to what only a decade ago would have been considered unthinkable. In the U.S. nuclear industry, the system has accomplished an excellent, nearly seamless process that succeeds to the benefit of both employee and utility owner.
F. J. Arias
Nuclear Science and Engineering | Volume 178 | Number 2 | October 2014 | Pages 240-249
Technical Paper | doi.org/10.13182/NSE13-88
Articles are hosted by Taylor and Francis Online.
The phenomenology for a particular behavior of packed beds in heavy liquid metal (HLM) fast reactors during postaccident heat removal is proposed. Because of the similar densities of the fuel and the HLM, an inherent passive safety self-removal feedback mechanism due to buoyancy forces is developed, which propels the packed bed away from the wall, thus preventing temperatures that can jeopardize the vessel’s structural integrity and also reducing the recriticality potential by limiting the allowable bed depth. This identified mechanism will have somewhat compensatory tendencies in the self-leveling behavior of debris beds, which are crucial for sodium-cooled reactors, but unfortunately, it is not operative for HLMs because of the absence of boiling of the coolant. By means of a simplified geometrical model, a preliminary analysis of the potentiality of the phenomenon has been performed.
