Neutronic modeling of megawatt-class heat pipe reactors

Megawatt-class heat pipe reactors (HPRs) have been identified as a candidate for the decentralized electricity markets, for instance, remote regions, island communities, and military bases. HPRs exhibit some unique designs, such as the encapsulated solid core with fuel pellets and heat pipes, control drums, and irregular reflectors. The neutronic tools are under development to investigate core characteristics and serve multiphysics coupling. This paper proposes a public neutronic benchmark of megawatt HPR of which all modeling parameters are available. This paper uses open-source Monte-Carlo code OpenMC to carry out the preliminary neutronic analysis of this benchmark. The influence of the cross-section library can be >750 pcm. The addition of axial structures zone can lead to >300 pcm reactivity increase. The Doppler effect of fuel exactly matches the oxide-fueled fast reactor Doppler constant formula. The reactivity worth of the control devices, flux distribution, power distribution, and depletion results are presented and accessible for future benchmarks. (C) 2021 Published by Elsevier Ltd.