Development of a Novel MCNP-OSCAR Fusion Interface for the 3-D Assessment of Gamma Dose Due to the Activated Corrosion Products

The gamma radiation field due to the activated corrosion products (ACPs) represents a key input for shielding design, licensing, and planning of maintenance operation. The present work aims to define and implement a reliable calculation chain based on the Outil de Simulation de la ContAmination en Réacteur–tOol of Simulation of ContAmination in Reactor (OSCAR)-Fusion and Monte Carlo N-Particle Transport (MCNP) codes for the assessment of 3-D gamma dose rate due to the ACPs. In particular, a piece of software has been developed to make easy the exchange of information between the codes: the MCNP neutron spectrum is processed to calculate the OSCAR neutron reaction rates; based on the OSCAR output and geometrical data, the 3-D gamma source is produced and exported in the surface source write/surface source read (WSSA/RSSA) MCNP format. Finally, a pure MCNP gamma transport provides the 3-D gamma dose rate distribution.