VVER KK NPP analysis using indigenous code system EXCEL-TRIHEXFA

Two Russian PWRs of the VVER-1000 MWe type are being built in Kudankulam, Tamilnadu. The capability to analyse these light water reactor systems has been developed in LWRPS, BARC. Reactor physics analysis of the VVER has been performed using the indigenously developed code system EXCEL-TRIHEXFA. The lattice parameter database using EXCEL code was expanded to include the full range of variation of burnup, boron, fuel and coolant temperatures, coolant density and saturated xenon loads for several power levels. Possibility to generate database with zero, equilibrium samarium or (Sm + Pm) has been recently introduced in EXCEL. This would help in estimation of samarium load during operation, after shutdown and subsequent restart of the reactor. The B4C controlled fuel also was simulated with full parametric variation. Space or mesh power dependent feedback models for xenon, Doppler, coolant temperature and density values have been incorporated in the core diffusion code TRIHEX-FA which has rendered the analysis more realistic. The core results include critical soluble boron concentration, three dimensional power, burnup and fuel/coolant temperature and coolant density distributions, and kinetics parameters including core average delayed neutron fraction β, prompt neutron mean life time ι and various reactivity coefficients. (author)