Development of CAD/MCNP interface program prototype for fusion reactor nuclear analysis

We developed a CAD/MCNP interface program prototype to easily perform Monte Carlo fusion nuclear design calculation with high accuracy using detailed calculation geometry. Usually, there is only CAD data on the solid region. However, CAD void region data must be input to MCNP. Our newly developed CAD/MCNP interface program creates the void region data automatically. The void region data is created by subtracting the solid region data using Boolean operations. The program has also the function of uniformly dividing the overall data into small cubes to simplify the void region data. It has been applied to create 3D CAD data in the ITER benchmark model. It was demonstrated that data of the void region in the ITER model were successfully created using our program.