Estimation of material degradation of VVER-1000 baffle

This article aims to show first steps towards deeper analysis of the baffle degradation process and to demonstrate the possibilities of precise calculation and measurements on the VVER-1000 mock-up in LR-0 reactor. Displacement per atom and gamma heating calculations were done with MCNP6 model of LR-0 VVER-1000 mock-up.The MCNP calculations provide data which are impossible to measure, such as deposited energy of particles. Completing this data with thermo-hydraulic computation, it is possible to assess void swelling. The same calculation has also be done with the TORT code. MCNP results for dpa and gamma heating in selected part of baffle are in an agreement with TORT results. Both distributions are comparable. Maximum dpa integrated over a year was estimated using MCNP as 2.5 and by TORT as 1.5 dpa. Maximum gamma heating in MCNP calculation is 4 W/cm³ compared with 8 W/cm³ in case of TORT. Used methods for absolute dpa and gamma heating estimation via MCNP calculations seems to be applicable for the VVER-1000 reactor. The reason for a variance in the absolute values are due to the slight differences in the 2 codes for nuclear parameters, geometry definition of computational models and by scaling process in MCNP