THE MONTE-CARLO CODES MCNP AND MCU FOR RBMK CRITICALITY CALCULATIONS

The modern Monte Carlo codes MCNP and MCU have been established as imp ortant tools to determine the neutronic behavior of reactor cores. For a comparison of their capabilities, detailed representations of seven critical experiments performed at the Russian Research Center 'Kurcha tov Institute' were developed, identical in geometry and material comp osition for each code. Despite the different philosophy of code develo pment, especially in the process of generating cross-section tables, t he calculated isotopic reaction rates and the flux distributions are i n excellent agreement. Effective multiplication factor and void reacti vity effect agree well with experiment. Additional uniform lattice cal culations confirm the equivalent potential of MCNP and MCU, but exhibi t significant differences to results achieved with transport codes lik e WIMS-D4. (C) 1998 Elsevier Science S.A. All rights reserved.