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Division Spotlight
Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
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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Apr 2025
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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.
Joffrey Dorville, Jacob Tellez, Conner Glatt, Andrew Osborne, Jenifer Shafer, Jeffrey King
Nuclear Technology | Volume 208 | Number 1 | December 2022 | Pages S26-S51
Technical Paper | doi.org/10.1080/00295450.2022.2072649
Articles are hosted by Taylor and Francis Online.
The Megawatt Implementation of a NuclEar ReActor using Low-enrichment uranium (MINERAL) is designed to deliver 2 MW(electric) of steady-state electricity to a colony established on the surface of Mars with a minimum lifetime of 10 years. The main challenge associated with a low-enrichment uranium fission surface power system is reducing the total mass, which will be higher than that of an equivalent high-enrichment uranium system. Optimizing the mass of the system is crucial to limit the amount of Earth-Mars cargo needed to deploy a MINERAL unit. The use of yttrium hydride as a moderator has shown promise in reducing the overall mass of the reactor. An in-house Python framework evaluates the neutronic, thermal-hydraulic, and heat rejection performance throughout the design process. The final design iteration uses a CO2 Brayton cycle cooled by a passive heat rejection system consisting of six panels with a total surface area of 4752 m2. The cylindrical core is fueled with low-enrichment uranium monocarbide with 0.83 wt% of pure 157Gd moderated with yttrium hydride and surrounded by a beryllium oxide reflector. The reactivity is controlled by ten control drums and a central control rod, which provide enough margin to operate the reactor and ensure its subcriticality in case of a submersion accident. The mass of the core with the reflector, reactivity control system, and shield is 7.2 tonnes.
