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Division Spotlight
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
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.
Yasushi Nomura, Hiroshi Okuno
Nuclear Technology | Volume 109 | Number 1 | January 1995 | Pages 142-152
Technical Paper | Nuclear Criticality Safety | doi.org/10.13182/NT95-A35074
Articles are hosted by Taylor and Francis Online.
For handling of nuclear fuel during reprocessing or for design of spent-fuel storage and transportation, one needs to know the scale of maximum credible criticality accidents, i.e., the total fission number so as to know the radiological exposure of working personnel as well as the risk to the public in the event of an accident. Some simplified evaluation models for conservatively predicting the number of total fissions during an accident are derived theoretically using the one-point adiabatic reactivity balance model for the homogeneous and heterogeneous systems, respectively, which are frequently seen in nuclear fuel facilities. These simplified evaluation models are subsequently validated with the transient experiment data and actual accident data published to date from the world nuclear community. Some conventionally used simplified evaluation models of this kind are quoted and compared with the results to show the convenience of the current models, having almost no restrictions in the application for any kind of nuclear fuel, material composition, geometry, and dimension, and thus, ensuring adequate margins for predicting the total fission number at the time of a critsssicality accident.
