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
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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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.
Alireza Haghighat, Moussa Mahgerefteh, Bojan G. Petrovic
Nuclear Technology | Volume 109 | Number 1 | January 1995 | Pages 54-75
Technical Paper | Material | doi.org/10.13182/NT95-A35068
Articles are hosted by Taylor and Francis Online.
The methodology used to prepare the source for neutron fluence calculation at the reactor pressure vessel is examined, and its effect on the calculated cavity dosimeter reaction rate is evaluated. Different source distributions for the Three Mile Island Unit 1 and Davis-Besse reactors and a simulated low low-leakage loading pattern are analyzed based on different levels of homogenization, different isotopic averaging approaches, contribution of 238U, use of the LEPRICON C factor formulation, and the SAILOR spectrum. Fuel isotopics can significantly affect the source distributions (through the fission spectrum), thereby leading to uncertainties of ∼7% in the calculated cavity dosimetry reaction rates. Higher uncertainties (>10%) are expected due to both the C factor and fission spectrum when the low low-leakage fuel designs are utilized.
