ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
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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Nuclear Science and Engineering
June 2025
Nuclear Technology
Fusion Science and Technology
May 2025
Latest News
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.
Joonhong Ahn
Nuclear Technology | Volume 117 | Number 3 | March 1997 | Pages 316-328
Technical Paper | Radioactive Waste Management | doi.org/10.13182/NT97-A35346
Articles are hosted by Taylor and Francis Online.
Redistribution of vitrified weapons-grade plutonium placed in the proposed Yucca Mountain repository is investigated based on the pure-colloid transport model for plutonium and the pure-solute transport model for plutonium, uranium, and boron. In the pure-colloid model, colloids carrying plutonium are assumed to settle out of groundwater in the fractures by floccu-lation. In the pure-solute model, 239Pu, 235U, and boron are transported through fractures by advection and diffuse into the rock matrix with sorption retardation. Both models show that 239Pu stays in the vicinity of the repository and decays there to 235U. All the 239Pu that originally exists in the repository reaches the bottom end of 200-m fractures as 235U. Boron spreads in the geologic medium during the glass leaching period and quickly disappears after the end of the leach time. Concentrations of 239Pu and 235U are found to be too small for autocatalytic criticality.
