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Division Spotlight
Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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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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.
John P. Holdren
Fusion Science and Technology | Volume 1 | Number 1 | January 1981 | Pages 79-89
Technical Paper | Fusion | doi.org/10.13182/FST81-A19917
Articles are hosted by Taylor and Francis Online.
Release of neutron-activation products in severe hypothetical fusion-reactor accidents may constitute a larger health hazard than that of the tritium released at the same time. Significant escape of activation products could result from lithium fires hot enough to melt and partly vaporize activated first-wall materials, or from other accident sequences that bring air into contact with activated structure hot enough to cause the formation of volatile metal oxides. Analysis of three combinations of structural materials and severe accident scenarios has been undertaken for an early conceptual tokamak reactor, using a simple consequence model based on that of the Nuclear Regulatory Commission's Reactor Safety Study (the Rasmussen report) to determine conceivable radiation doses near the plant boundary. (No attempt was made to estimate probabilities for such severe events.) In the cases of stainless-steel and molybdenum structures subject to massive lithium fires, the boundary doses far exceed those that would be produced by release of the entire plant inventory of tritium and are comparable to the doses similarly calculated for “worst case” light water reactor accidents. The case of niobium fusion-reactor structure is more favorable. These results, based on an early fusion-reactor design not optimized with respect to safety characteristics, may well portray a worst case picture of fusion accident consequences. They suggest, however, that the large potential safety advantages of fusion compared to fission are not necessarily inherent for all designs and choices of materials, and they motivate attention to the several available strategies for greatly reducing the potential for activation-product release from fusion reactors.