Investigation of BeO as a reflector for PWR

A typical PWR is simulated using the Monte Carlo MCNP5 code to study the impact of using BeO, as a reflector on the power peaking factor, core average discharge burnup and the core operating cycle. Three cases with different fuel enrichments, different soluble boron concentrations and different uniform distribution of burnable poisons concentrations are studied. The calculations showed that a 20 cm BeO reflector with a combination of an optimized three batch cores would ideally lead to a perfect flattening of the power distribution. Many trails are carried out to optimize the core map and fuel enrichments. Assembly peaking factors less than 1.08 are obtained for the three cases which increase the core average discharge burnup to about 92% from the optimum or licensing limits. Also a fairly flat distribution of plutonium formation throughout the core is obtained which help in keeping the flattening of the power distribution throughout the core life. With this flattening of the burnup distribution, all assemblies will be loaded once and there is no shuffling is needed. This increases the operating cycles and reduces the outage frequency and increases the capacity factor. All of these will improve the uranium utilization and reduce the operating costs of the nuclear power plant. (authors)