Research on the application of burnable poison ZrB2 and Gd2O3 in a small modular lead-based thermal reactor

•Analysis of BPs in a small modular lead-based thermal reactor was carried out.•A small modular lead-based thermal reactor was constructed with the SuperMC code.•The burnup characteristics of ZrB2 and Gd2O3 were investigated and compared.•An optimized core was proposed and main neutronics parameters were analyzed.