Burn-up Analysis for a PWR Fuel Pin of the Next Reactor Generation

A computer model was d eigned to analyze a benchmark problem suites for studying the physics of next generation fuels of light water reactors (LWRs). The target discharge burn-up of the next generation fuel was set to 70 GWd/t considering the increasing trend in discharge burn-up of light water reactor fuels. UO2 and MOX fuels are included in the benchmark specifications. The benchmark problem consists of burn-up of fuel pin cell for UO2 and MOX. In the pin cell problem, detailed nuclear characteristics were calculated with fuel burn-up. Other methodology to perform uncertainty analysis is random simulation or Monte Carlo (MC) method. To apply this methodology, information about the joint probability distribution of the nuclear data errors is necessary. Deferent assumptions can be made about the probability distribution; the simplest and more usual (in many other areas) is the normal distribution. Based on Monte Carlo Method, MCNPX computer code was used to simulate one fuel rod and then the results were analyzed. The stated model has been verified by comparing the axial power distribution for homogeneous and heterogeneous fuel rod of UO2 fuel where typical agreements have obtained. In this study, it was found that with enrichment 6.2% and after 1890 days, the multiplication factor for UO2 fuel pin decreased from 1.49 to 0.975 and for MOX fuel pin decreased from 1.272 to 1.259 which guarantee continues work for more than two years. Also for UO2 fuel pin the concentration of Uranium and Plutonium isotopes were determined with burn-up and for MOX fuel pin the concentration of Uranium, Americium, curium and Neptunium isotopes were declared with burn-up.