Power Peaking Factor in the Start up Core of the MPR Reactor

Power peaking factor for a nuclear reactor is a safety issue. Therefore, the exact knowledge of the local and global power peaking in the reactor core is of great importance. The direct measurement of power peaking factor is not possible. Instead of that, depending on thermal flux measurements and prediction by calculations this factor can be estimated. The point at issue, this factor was estimated for the MPR reactor by the reactor designer for the startup core. In this estimation the peaking zone and the power distribution were determined by a diffusion computer code. We decided in this work to predict the local and global power peaking factors of the MRP startup core by a Monte Carlo computer code, which is more accurate than the diffusion code used by the reactor designer, to have reference values for comparison