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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
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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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.
V. Jagannathan, Usha Pal, R. Karthikeyan, S. Ganesan, R. P. Jain, S. U. Kamat
Nuclear Technology | Volume 133 | Number 1 | January 2001 | Pages 1-32
Technical Paper | Fission Reactors | doi.org/10.13182/NT01-A3156
Articles are hosted by Taylor and Francis Online.
A new reactor concept has been proposed for induction of thorium in an enriched uranium reactor. The neutronic characteristics of the fissile and fertile materials have been exploited to arrive at optimal fuel assembly and core configurations. Each fuel assembly consists of an enriched uranium seed zone and a thoria blanket zone. They are in the form of ring-type fuel clusters. The fuel is contained in vertical pressure tubes placed in a hexagonal lattice array in a D2O moderator. Boiling H2O coolant is used. The 235U enrichment is ~5.4%. The thoria rods contain the 233U bred in situ by irradiation of one batch load of mere thoria clusters (without the seed zone) for one fuel cycle in the same reactor. There is no need for external feed enrichment in thoria rods. Additionally, some moveable thoria clusters are used for the purpose of xenon override. The fissile production rate from the fertile material and the consumption rate of fissile inventory is judiciously balanced by the choice of U/Th fuel rod diameter and the number and location of thoria rods in the fuel assembly and in the core. During steady-state operation at rated power level, there is no need for any conventional control maneuvers such as change in soluble boron concentration or control rod movement as a function of burnup. Burnable poison rods are also not required. A very small reactivity fluctuation of ±2 mk in 300 effective full-power days of operation is achieved and can be nearly met by coolant inlet enthalpy changes or moveable thoria clusters. Control is required only for cold shutdown of the reactor. The uranium as well as thoria rods achieve a fairly high burnup of 30 to 35 GWd/tonne at the time of discharge. Since the excess reactivity for hot-full-power operation is nearly zero at all times during the fuel cycle and since the coefficients of reactivity due to temperature and density variations of coolant are nearly zero by design, there is hardly any possibility of severe accidents involving large reactivity excursions.