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Division Spotlight
Education, Training & Workforce Development
The Education, Training & Workforce Development Division provides communication among the academic, industrial, and governmental communities through the exchange of views and information on matters related to education, training and workforce development in nuclear and radiological science, engineering, and technology. Industry leaders, education and training professionals, and interested students work together through Society-sponsored meetings and publications, to enrich their professional development, to educate the general public, and to advance nuclear and radiological science and engineering.
Meeting Spotlight
Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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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Nuclear Technology
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Fusion Science and Technology
Latest News
The JT-60SA project
JT-60SA (Japan Torus-60 Super Advanced) is the world’s largest superconducting tokamak device. Its goal is the earlier realization of fusion energy (see Fig. 1). Fusion is the energy that powers the Sun, and just 1 gram of deuterium-tritium (D-T) fuel produces enormous energy—the equivalent of 8 tons of crude oil.
Last fall, the JT-60SA project announced an important milestone: the achievement of the tokamak’s first plasma. This article describes the objectives of the JT-60SA project, achievements in the operation campaign for the first plasma, and next steps.
C. D. Andriesse, R. H. J. Tanke
Nuclear Technology | Volume 65 | Number 3 | June 1984 | Pages 415-421
Technical Paper | Nuclear Safety | doi.org/10.13182/NT84-A33397
Articles are hosted by Taylor and Francis Online.
Existing data on the release of fission products (FPs) from UO2 above 1000°C show that the dominant transport process consists of elementary diffusion within grains. For many FPs, the noble gases among them forming an exception, this diffusion is characterized by an activation energy of ∼2.6 eV, which is close to the one for oxygen and very different from the one for uranium. Assuming that oxygen diffusion represents the diffusion of FPs, it can be predicted that diffusion is enhanced when there is excess oxygen in the lattice. An empirical relation between the pertinent activation energy and the overstoichiometry induced by uranium fission (burnup) is given. The transport by diffusion has to be driven by some gradient, and it is argued that the temperature gradient dominates over the concentration gradient. This argument leads to a complete description of the release rate in terms of the grain size, the central and surface temperatures, and the heat of transport. The heat of transport plays a crucial role as it varies greatly for the various FPs. Existing data allow estimation of values ranging from 0.1 eV for refractory products to more than 100 eV for volatile products. These variations appear to be correlated with variations in the bond strengths between FPs and oxygen, being the more reactive element in UO2. An empirical model of the dependence of the heat of transport on this bond strength is given, so that release rates for all the FPs can be derived from chemical tables. Finally, consistency of the measured release data with other independently obtained fuel parameters is proven.