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
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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
Jun 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
August 2025
Nuclear Technology
July 2025
Fusion Science and Technology
Latest News
NRC cuts fees by 50 percent for advanced reactor applicants
The Nuclear Regulatory Commission has announced it has amended regulations for the licensing, inspection, special projects, and annual fees it will charge applicants and licensees for fiscal year 2025.
Jaeuk Im, Myung Jin Jeong, Namjae Choi, Kyung Min Kim, Hyoung Kyu Cho, Han Gyu Joo
Nuclear Science and Engineering | Volume 197 | Number 8 | August 2023 | Pages 1743-1757
Technical papers from: PHYSOR 2022 | doi.org/10.1080/00295639.2022.2143209
Articles are hosted by Taylor and Francis Online.
A multiphysics analysis system for neutronics/thermomechanical/heat pipe thermal analysis of heat pipe–cooled micro reactors was developed using the PRAGMA code as the neutronics engine. PRAGMA, which was developed as a graphics processing unit (GPU)-based continuous-energy Monte Carlo code for power reactor applications, now has an extended geometry package to handle geometries with unstructured meshes generated by Coreform Cubit. The NVIDIA ray-tracing engine OptiX has been exploited for efficient neutron transport on unstructured mesh geometry. On the multiphysics side, the open-source computational fluid dynamics tool OpenFOAM and one-dimensional heat pipe analysis code ANLHTP have been adopted. The manager-worker system based on the message passing interface dynamic process management model enables efficient coupling of codes employing different parallelization schemes. With all the features, the multiphysics analysis of the 60-deg symmetrical sector model of the MegaPower three-dimensional core was performed for normal operation and heat pipe–failed conditions. The multiphysics coupling run time was about 2.5 h, in which the Monte Carlo simulation employing more than 10 billion histories was performed within half an hour on a single rack of computing nodes mounted with 24 NVIDIA Quadro GPUs. Accordingly, this demonstrates the soundness and robustness of the tightly coupled three-way multiphysics analysis system.