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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
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver Downtown
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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Dragonfly, a Pu-fueled drone heading to Titan, gets key NASA approval
Curiosity landed on Mars sporting a radioisotope thermoelectric generator (RTG) in 2012, and a second NASA rover, Perseverance, landed in 2021. Both are still rolling across the red planet in the name of science. Another exploratory craft with a similar plutonium-238–fueled RTG but a very different mission—to fly between multiple test sites on Titan, Saturn’s largest moon—recently got one step closer to deployment.
On April 25, NASA and the Johns Hopkins University Applied Physics Laboratory (APL) announced that the Dragonfly mission to Saturn’s icy moon passed its critical design review. “Passing this mission milestone means that Dragonfly’s mission design, fabrication, integration, and test plans are all approved, and the mission can now turn its attention to the construction of the spacecraft itself,” according to NASA.
Dong-Kwon Keum, Chung-Kyun Park, Pil-Soo Hahn, Tjalle T. Vandergraaf
Nuclear Technology | Volume 120 | Number 3 | December 1997 | Pages 211-223
Technical Paper | Radioactive Waste Management | doi.org/10.13182/NT97-A35412
Articles are hosted by Taylor and Francis Online.
Modifications have been made to an existing stratified channel contaminant transport model by incorporating hydrodynamic dispersion in each channel. The integrals in the modified model are solved by a numeric method. Gaussian quadrature integration formulas were used to solve the equation, including the Gauss-Laguerre quadrature to deal with the upper infinite limit of the integral. This approach proved to be both accurate and efficient. The effects of physicochemical parameters on the elution breakthrough curve have been studied with this model. The parameters that were considered were (a) the standard deviation of a lognormal distribution of the channel width, (b) longitudinal dispersivity, (c) water velocity, (d) fracture length, (e) surface sorption coefficient, and (f) rock matrix diffusivity. Results from the calculations showed that the hydrodynamic dispersion in each channel caused additional dispersion in the elution profile. A new parameter, which quantifies rock matrix dif fusion and residence time of the solute in the fracture simultaneously, and its reference value are presented. This parameter is useful to determine numerically if the diffusion into the rock matrix is a significant contribution to the transport of the tracer through the fracture. This parameter can also be used in the design of migration experiments intended to observe diffusion into the rock matrix. The modified model has been used to analyze two independent experimental data sets obtained for a conservative tracer, one obtained in an artificial fracture and the other in a natural fracture. The results obtained with this modified model were in good agreement with both sets of experimental results. The dispersivities for both experimental systems were determined by curve fitting, and similar values were obtained for both types of fracture. The values obtained for the natural fracture especially indicated that both local hydrodynamic and channeling dispersion occurred.
