PWR control rods position monitoring

This study investigates the best radial positions for the monitoring detectors inside the reactor core, which provides close monitoring to enhance reactor safety. These positions depend on flux distortion due to reactivity change induced by accidental drop of a control rod into the core, as one of the causes of the reactivity change. Thermal neutron flux shape after each control rod group and rod cluster insertion is estimated to show the maximum distortion in neutron flux shape. The study aims to define the maximum distortion case by means of correlation coefficients corresponding to the data that were calculated using the three dimensional diffusion depletion code TRITON. Correlation coefficient and reactivity were determined for each rod cluster control (RCC) assembly. For each case, the change in shape of the thermal flux was determined in case of full insertion or accidental drop of one of the rod cluster control (RCC) assemblies in the reactor core at full power.