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Division Spotlight
Fusion Energy
This division promotes the development and timely introduction of fusion energy as a sustainable energy source with favorable economic, environmental, and safety attributes. The division cooperates with other organizations on common issues of multidisciplinary fusion science and technology, conducts professional meetings, and disseminates technical information in support of these goals. Members focus on the assessment and resolution of critical developmental issues for practical fusion energy applications.
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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Fusion Science and Technology
Latest News
ARPA-E announces $40 million to develop transmutation technologies for UNF
The Department of Energy’s Advanced Research Projects Agency–Energy (ARPA-E) announced $40 million in funding to develop cutting-edge technologies to enable the transmutation of used nuclear fuel into less-radioactive substances. According to ARPA-E, the new initiative addresses one of the agency’s core goals as outlined by Congress: to provide transformative solutions to improve the management, cleanup, and disposal of radioactive waste and spent nuclear fuel.
D. R. Harding, D. Whitaker, C. Fella
Fusion Science and Technology | Volume 70 | Number 2 | August-September 2016 | Pages 173-183
Technical Paper | doi.org/10.13182/FST15-211
Articles are hosted by Taylor and Francis Online.
The accepted mechanism for the formation of a deuterium-tritium (D-T) ice layer is that mass evaporates (sublimes) from the warmer regions of the shell and deposits in the cooler regions. Recent observations of the early-stage formation of single-crystal ice layers in OMEGA targets show that the rate and direction of crystal growth are influenced by liquid wicking to the crystal growth surface. This behavior is attributed to the ice-liquid interface possessing a lower surface energy than the ice-vapor interface, and the amount of liquid transported by this process is determined by the size, position, and growth rate of the initial seed crystal. Appreciating this behavior allowed us to define an improved cooling ramp that balances the rate at which heat was removed from the target with the supply of liquid to the crystal growth surface. The time and temperature parameters used to form a seed crystal and then grow the crystal into a complete ice layer are presented. One benefit of this process may be fewer defects in the ice layer. The target was cooled to 0.6 K below the temperature where it was formed before strain-induced crystallographic features developed. An estimate of the extent of fractionation of D2, D-T, and T2 isotopes during the freezing cycle was based on the thickness uniformity of the ice layer and how the crystal grew. The region where the ice layer initially formed was 4% thinner than the region where its formation was complete. The alignment of this perturbation to the ice layer with the growth axis of the crystal suggests, to a first-order approximation, that the area of the crystal that first formed possessed a higher fraction (~4%) of tritium atoms.