Preliminary neutronics analysis for generation III⁺ VVER design - VVER-1200

Preliminary Neutronics analysis of a new generation first of the kind VVER-1200 has been carried out to develop independent physics analysis capability to support in its future safety evaluations and licensing processes. An open-source Monte Carlo (OpenMC) code with LANL released ENDF/BVIII. 0 nuclear data is used for the purpose. To begin with, validation of the lattice and core models of OpenMC simulations, which are carried out based on the literature information, is established by comparing the effective neutron multiplication factor (K_eff) estimated for a normal operating condition with the literature. Comparison shows that the prediction capability of OpenMC code is at par with the other international state-of-the-art codes. After acquiring adequate confidence in the modelling, the analysis has been extended to study the inherent safety parameters viz. fuel and moderator temperature coefficients of reactivity at the lattice (fuel assembly) as well as core level. Behavioral changes of the parameters of interest from lattice to core level are studied and reported. (author)