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ORIGINAL RESEARCH article

Front. Nucl. Eng.
Sec. Nuclear Reactor Design
Volume 3 - 2024 | doi: 10.3389/fnuen.2024.1483520
This article is part of the Research Topic Multiphysics Methods and Analysis Applied to Nuclear Reactor Systems View all articles

On-The-Fly Thermal Expansion for Monte Carlo Multi-Physics Reactor Simulations

Provisionally accepted
Muhammad Imron Muhammad Imron 1Deokjung Lee Deokjung Lee 1,2*
  • 1 Ulsan National Institute of Science and Technology, Eonyang, Republic of Korea
  • 2 Advanced Nuclear Technology and Services, Ulsan, Republic of Korea

The final, formatted version of the article will be published soon.

    In this study, we present on-the-fly thermal expansion methodology for direct Monte Carlo coupled multi-physics reactor simulations. This approach allows the problem geometry to be thermally expanded on-the-fly during particle tracking using local temperatures, such as pin-averaged temperatures, obtained from the thermal-hydraulics solver. Numerical experiments demonstrated that modeling thermal expansion with local temperatures for thermal expansion improves the accuracy of reactor simulations, both for reactor eigenvalue and pin powers, compared to using global core-averaged temperatures. Additionally, the use of thermal expansion also improves the isothermal temperature coefficients, making them approximately 0.77 pcm/K closer to the measured data. Finally, results for depletion problems showed that incorporating thermal expansion in direct reactor modeling enhances the predicted critical boron concentration, particularly at high power and higher fuel burnup. These findings suggest that including thermal expansion in reactor modeling is essential for improving the fidelity of simulations.

    Keywords: thermal expansion, monte carlo, multi-physics, Reactor simulations, Neutron transport

    Received: 20 Aug 2024; Accepted: 25 Sep 2024.

    Copyright: © 2024 Imron and Lee. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Deokjung Lee, Ulsan National Institute of Science and Technology, Eonyang, Republic of Korea

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.