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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.
Abdelfatah Abdelmaksoud, Said Haggag, Magdy M. Zaky, Moussa Osman
Nuclear Technology | Volume 208 | Number 9 | September 2022 | Pages 1471-1483
Technical Paper | doi.org/10.1080/00295450.2022.2035644
Articles are hosted by Taylor and Francis Online.
In the present study, an analysis of a hypothetical complete loss-of-coolant accident in a typical open-pool research reactor is conducted. The reactor core is assumed to be completely uncovered and exposed to the ambient air. The possibility of passively cooling the decay heat of the exposed reactor core by natural convection to air and thermal radiation until core reflooding is investigated. A three-dimensional computational fluid dynamics analysis is conducted for the uncovered core while cooled by air natural convection and thermal radiation. The reactor core is simulated as a porous zone with decay heat generation specified as a cosine-shape distribution. The reactor core decay heat acts as a driving force for the coolant flow from the cold leg to the hot leg. The thermal equilibrium porous media model is used to represent the energy equation inside the core region. This study is conducted for core uncover time (the time interval between reactor shutdown and the moment when the reactor core is drained of water) of 10E3, 10E4, 10E5, 10E6, 10E7, and 10E8 s. Contour plots of temperature, velocity, density, and pressure at different values of core uncover time are illustrated. It’s found that for core uncover times of 10E3, and 10E4 s, the maximum core temperature exceeds the cladding melting point. The core maximum temperature is well below the melting point for uncover times of 10E5, 10E6, 10E7, and 10E8 s.