https://doi.org/10.1051/epjn/2025068
Regular Article
Development of an adjoint flux calculation technique for exact perturbation theory in Monte Carlo transport
1
Department of Nuclear Engineering, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 44919, Republic of Korea
2
Advanced Nuclear Technology and Services, 406-21 Jonga-ro Jung-gu, Ulsan, 44429, Republic of Korea
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Received:
1
July
2025
Received in final form:
22
September
2025
Accepted:
1
October
2025
Published online: 16 January 2026
A calculation technique computing the adjoint flux of perturbed system is developed for the exact perturbation theory in Monte Carlo transport. By using a correlated sampling and iterated fission probability methods together, the adjoint flux of perturbed system is calculated during a forward Mote Carlo simulation of an unperturbed system. In the perturbation-included iterated fission probability method, no additional particle simulation is required to compute the adjoint flux of perturbed system. The exact perturbation method is implemented in the Monte Carlo code MCS. The results of perturbation method for k-eigenvalue change are compared against differential operator sampling, adjoint-weighted perturbation, and direct perturbation methods for the Godiva benchmark and PLUS7 fuel assembly.
© Y. Jo and D. Lee, Published by EDP Sciences, 2026
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
