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
Young Members Group
The Young Members Group works to encourage and enable all young professional members to be actively involved in the efforts and endeavors of the Society at all levels (Professional Divisions, ANS Governance, Local Sections, etc.) as they transition from the role of a student to the role of a professional. It sponsors non-technical workshops and meetings that provide professional development and networking opportunities for young professionals, collaborates with other Divisions and Groups in developing technical and non-technical content for topical and national meetings, encourages its members to participate in the activities of the Groups and Divisions that are closely related to their professional interests as well as in their local sections, introduces young members to the rules and governance structure of the Society, and nominates young professionals for awards and leadership opportunities available to members.
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!
Latest Magazine Issues
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
June 2025
Nuclear Technology
May 2025
Fusion Science and Technology
Latest News
Sam Altman steps down as Oklo board chair
Advanced nuclear company Oklo Inc. has new leadership for its board of directors as billionaire Sam Altman is stepping down from the position he has held since 2015. The move is meant to open new partnership opportunities with OpenAI, where Altman is CEO, and other artificial intelligence companies.
Inhyung Kim, HyeonTae Kim, Yonghee Kim
Nuclear Science and Engineering | Volume 194 | Number 1 | January 2020 | Pages 14-31
Technical Paper | doi.org/10.1080/00295639.2019.1654815
Articles are hosted by Taylor and Francis Online.
This paper presents a systematic way to truncate the high-fidelity Monte Carlo (MC) solution to reduce the computational cost without compromising the essential reliability of the solution. Based on the fine-mesh finite difference (FMFD) acceleration for the MC analysis, the deterministic truncation of the Monte Carlo (DTMC) solution method is developed and investigated for a systematic approximation to the MC solution of the reactor eigenvalue problem. This deterministic solution is used for the acceleration of the MC simulation as well as the solution prediction itself. The concept, motivations, and challenges of the DTMC method are described in detail, and theoretical backgrounds of the FMFD method are discussed. In addition, an unbiased ratio estimator for more accurate FMFD parameter generation and a modified particle ramp-up method for the determination of optimal generation size in the MC simulation are also introduced and explained. Both the C5G7 benchmark and a small modular reactor (SMR) core are analyzed to characterize the numerical performance of the DTMC method in this work. Convergence behavior of the fission source distribution is examined, and reactor parameters such as the multiplication factor and three-dimensional pin power distribution are estimated and compared to the reference solution. The stochastic features of the DTMC solutions are also discussed in terms of the apparent and real standard deviations. For the pin power distribution, the root-mean-square error and relative error for the reactor core are also evaluated and compared. The computing time and figure of merit are compared for each method.