Criticality benchmark of VVER-1000 fresh fuel assembly with MCNP

IAEA benchmark problem for VVER-1000 reactor fresh fuel assemblies has been evaluated through Monte Carlo (MC) simulation. Infinite multiplication factor (k∞) values are calculated for different hexagonal fuel assemblies with 2 wt%, 3 wt%, 3.22 wt% and 3.3 wt% enriched U-235. MC simulations have been performed with the computer code MCNP at different temperatures 120°C, 278°C, 280°C, 302°C and 305°C for three different conditions: (i) 0 ppm soluble boron concentration, (ii) 1000 ppm soluble boron concentration, and (iii) full insertion of control rod clusters (absorber material, B4C) without boron in the moderator. The results are in good agreement with the deterministic calculations as reported in IAEA-TECDOC-847.