Shobyr Ashkpour-Motlagh

Consideration of power control problems and protection of core melt accidents are very important. In this thesis, simulation of a VVER-1000 reactor core has been performed using the MCNP code. Three dimensional configuration of the core has been plotted. The simulated core consists of fuel rods, absorber and control rods, central tubes, sensor tubes, coolant (moderator) and reflectors. The radial and axial neutron fluxes have been calculated in the active core with its nominal power. Taking a meltdown core, the radial and axial neutron fluxes have been determined. The strong effect of the meltdown core on the neutron flux has been described.