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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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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.
Robert E. Henry
Nuclear Science and Engineering | Volume 193 | Number 7 | July 2019 | Pages 790-799
Technical Paper | doi.org/10.1080/00295639.2018.1560855
Articles are hosted by Taylor and Francis Online.
Evaluations of severe accident conditions for water-cooled reactors with metallic fuel pin cladding must consider the oxidation of this material for accident sequences that could lead to high metal temperatures in a steam environment. Such representations are included in integral accident analysis computer codes. If the oxidation causes sufficiently high temperatures to melt, or liquefies the core materials, the core geometry changes as the melt drains downward and freezes on cooler structures promoting blockages and redirection of steam flowing through the fuel assemblies. Once this configuration forms, the accident condition is characterized as the late phase of core oxidation. The Phebus in-reactor experiments investigated hydrogen generation in this compacted core state and measured the generation rates over several thousand seconds. This paper investigates the role of countercurrent steam-hydrogen flow to the debris upper surface as a limit for the generation rate and finds that this provides a close description of the behavior for the Phebus experiments. Applying this mechanism to reactor accident conditions shows how this should be considered in the Severe Accident Management Guidelines.