HTR steady state and transient thermal analyses

•Steady state and transient thermal simulations of the 10 MW HTR-10 are presented.•Simulations were performed using the RELAP5-3D code.•Results were compared with data from an available benchmark with good agreement.•The developed model was capable of reproducing the thermal behavior of the HTR-10.

A thermal model to simulate the steady state and transient behavior of the 10 MW pebble bed high temperature gas cooled reactor (HTR-10) is presented in this work. The helium cooled HTR-10 was designed, constructed and operated by the Institute of Nuclear and New Energy Technology (INET), in China. In this study, a simulation is performed using the RELAP5 code. In the simulation, results of temperature distribution within the pebble bed, inlet and outlet coolant temperatures, coolant mass flow, and others parameters have been compared with the data available in a benchmark document published by the International Atomic Energy Agency (IAEA) in 2013. The simulation is demonstrated to be in good agreement, showing that the developed model is capable of reproducing the thermal behavior of the HTR-10 in steady state and transient operation conditions.