Software development for pebble-bed MSR calculation

Molten salt reactor (MSR), the unique liquid fuel reactor in the fourth generation nuclear power system, has great advantages in terms of inherent safety, neutron economy, nuclear non-proliferation, nuclear waste transmutation and thorium fuel breeding, compared with other solid fuel reactors. At present, there are two main types of molten salt reactor in domestic: Hexagonal assembly MSR and pebble-bed MSR. In this paper, the pebble-bed MSR fuel sphere homogenization method was studied with double heterogeneity characteristics taken into consideration, and the core fuel management code BORAGE was developed based on SIXTUS 3-D hexagonal node diffusion code. Numerical results suggest that the developed code achieves good accuracy, efficiency and can be used in MSR steady analytical calculation. (authors)