Model Analysis of Monte-Carlo Method for First Criticality Physics Calculation in Pebble Bed High Temperature Gas-Cooled Reactor

The present study compared and analyzed the geometry treatments used for 10 MW High Temperature Gas-Cooled Reactors（HTR-10） initial criticality calculation,and TRIPOLI-4.3 and MCNP4B codes based on Monte-Carlo method were employed to describe the random arrangement of Coated Fuel Par-ticles（CFPs） in the fuel pebbles and the random distribution of the fuel and dummy pebbles in the core.HTR-10 initial criticality was calculated with TRIPOLI-4.3 code and compared with the previous results from MCNP4B.The present study showed that Monte Carlo codes TRIPOLI-4.3 as well as MCNP4B could be used in the first criticality physics calculations for pebble bed High Temperature Gas-Cooled Reactors by adopting appropriate geometry modellings.