The kilowatt reactor using stirling technology (KRUSTY) is a heat-pipe-cooled reactor experimental system that uses a Stirling engine to convert thermal energy to electricity, it is the only one published experimental data for heat-pipe-cooled reactor systems. The KRUSTY experimental data under different working scenarios include the cold startup and load change processes, heat pipe failure, reactivity insertion, and heat sink loss.

This study aims to validate the self-developed system transient analysis code named TAPIRS-D for the heat-pipe-cooled reactor concept using KRUSTY experimental data.

Firstly, an in-house system code for a heat-pipe-cooled reactor named TAPIRS-D was introduced, with the main theoretical module briefly explained, including the reactor power calculation module, heat transfer module for fuel assembly, and heat pipes. Then, the TAPIRS-D was applied for the first time to the simulation of the key processes of the KRUSTY prototypic reactor test under normal operation and accident conditions. Finally, comparison between the simulation data and experimental data was conducted for the validation of this analysis code.

Comparison results demonstrate that the maximum relative prediction error for the fuel temperature is less than 2%, and the reactor power average prediction error is less than 10%.

The prediction trend of the numerical simulation by TAPIRS-D fits well with the experimental data on key parameters such as core power and the temperature of fuel and heat pipes, which indicates that TAPIRS-D is well developed and is capable of conducting safety analysis for heat pipe cooled reactor concepts. The validation of this system analysis code provides a good reference for other newly developed system codes for heat pipe reactors.