ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
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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Nuclear Science and Engineering
June 2025
Nuclear Technology
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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.
Digby D. Macdonald, Iouri Balachov
Nuclear Technology | Volume 120 | Number 1 | October 1997 | Pages 86-93
Technical Note | Material | doi.org/10.13182/NT97-A35434
Articles are hosted by Taylor and Francis Online.
The viability of an often-employed engineering method of determining bottom drain (lowerplenum) oxygen levels in boiling water reactors is explored, in which bottom drain oxygen is back-calculated from the recirculation system oxygen level and the combined recirculation system/bottom drain value. For a low flow fraction f where 0.16 <f <0.20 is often employed, the back-calculated bottom drain oxygen level can be grossly in error, reflecting the minimal amount of information that is derived from the lower plenum. This finding cautions against using back-calculated lower plenum oxygen levels to specify hydrogen water chemistry conditions for protection of the components in the lower plenum, particularly when f is small. The uncertainty in the bottom drain [O2I has been characterized by using a Monte Carlo error analysis for both systematic and random errors. Modifications to the sampling system that would greatly reduce these errors are identified.
