New Approach to Space-Dependent Kinetic Analysis by the Integral Kinetic Model

This work aims to show the possibility of using the integral kinetic model, which is applicable to any geometry, for general space-dependent kinetic analysis. A space-dependent kinetic analysis methodology and code were developed based on the integral kinetic model. The developed kinetic analysis code was verified by comparing results from the developed code with the one-point model in the Godiva reactor geometry. It is possible to explain discrepancies between the two kinetic models using error introduced into Cij(τ) in the fitting process of original Monte Carlo data Cij(kΔτ). This is because the fitting error changes the mean generation time of a system. The verification concluded that it is important to always monitor the fitting error introduced to Cij(τ) in order to understand the calculation results of the developed code. The space-dependent kinetic analysis code was also demonstrated in a fast-thermal coupled reactor geometry including feedback effects. The demonstration results showed a time difference in kinetic behaviors between a fast region and a thermal region that was theoretically expected to appear. In conclusion, this work shows a new approach to solving general space-dependent kinetic problems by using the integral kinetic model including feedback effects.