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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.
Motoo Fumizawa
Nuclear Technology | Volume 109 | Number 2 | February 1995 | Pages 236-245
Technical Paper | Heat Transfer and Fluid Flow | doi.org/10.13182/NT95-A35056
Articles are hosted by Taylor and Francis Online.
An experimental investigation was carried out for the buoyancy-driven exchange flow in a narrow vertical pipe concerning the air ingress process during a standpipe rupture in a high-temperature gas-cooled reactor. In the current study, the evaluation method of exchange flow was developed by measuring the velocity in the pipe using a laser Doppler velocimeter. The experiments were performed under atmospheric pressure with nitrogen as a working fluid. The Rayleigh numbers range from 2.0 × 104 to 2.1 × 105. The exchange flow fluctuated irregularly with time and space in the pipe. It was found that the exchange-velocity distribution along the horizontal axis changed from one- to two-humped curves with increasing Rayleigh number. In the case that the lower plenum wall was cooler than the heated disk, the volumetric exchange flow rate was smaller than that in the case where the lower plenum wall and heated disk were kept at the same temperature.
