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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Apr 2025
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Nuclear Science and Engineering
May 2025
Nuclear Technology
Fusion Science and Technology
April 2025
Latest News
Waste Management 2025: Building a new era of nuclear
While attendance at the 2025 Waste Management Conference was noticeably down this year due to the ongoing federal retrenchment, the conference, held March 9-13 in Phoenix, Ariz., still drew a healthy and diverse crowd of people working on the back end of the nuclear fuel cycle, both domestically and internationally.
Zachary K. Hardy, Jim E. Morel, Jan I. C. Vermaak
Nuclear Science and Engineering | Volume 199 | Number 4 | April 2025 | Pages 599-612
Research Article | doi.org/10.1080/00295639.2024.2384223
Articles are hosted by Taylor and Francis Online.
The second moment method is a linear acceleration technique that couples the transport equation to a diffusion equation with transport-dependent additive closures. The resulting low-order diffusion equation can be discretized independent of the transport discretization, unlike diffusion synthetic acceleration, and is symmetric positive definite, unlike quasidiffusion. While this method has been shown to be comparable to quasidiffusion in iterative performance for fixed source and time-dependent problems, it is largely unexplored as an eigenvalue problem acceleration scheme due to the belief that the resulting inhomogeneous source makes the problem ill posed. Recently, a preliminary feasibility study was performed on the second moment method for eigenvalue problems. The results suggested comparable performance to quasidiffusion and more robust performance than diffusion synthetic acceleration. This work extends the initial study to more realistic reactor problems using state-of-the-art discretization techniques. The results in this paper show that the second moment method is more computationally efficient than its alternatives on complex reactor problems with unstructured meshes.