Application of Discrete Ordinate and Monte-Carlo Coupling Method for Reactor Shielding Calculation

A coupling calculation method based on the discrete ordinate method code DOT and Monte-Carlo method code MCNP was realized. By automatically providing a binary source specification file for the surface source function of MCNP（i.e. SSR command）, this coupling method was achieved and subsequently the necessity of re-compiling of MCNP code was eliminated. This coupling method was applied in the shielding problem of rooms around the pit of reactor cavity and a good agreement was obtained between the calculation and measurement results, which validated the correctness of this coupling method. Further more, source bias method was implemented in this coupling method, which shows great efficiency in variance reduction and the improvements of calculation efficiency.