Kinetics Analysis for Thermal Reactor Core by Continuous Energy-Time Monte Carlo Method

Abstract

To get more insights into the neutron kinetics process with an affordable cost in computing time, a weight Monte Carlo (wMC) branchlesskinetics method is derived, implemented,and verified to analyze the neutron-kinetics process in the continuous-energy and time phase-space in this paper. This method is derived based on theunbiased-samplingprinciple and the normalization principle of cross sections, with the neutron and precursor densities explicitly considered. These principles provide a theoretical basis for wMC and further researches. Then, a Monte Carlo kinetics code named NECP-Dandi is developed and verified by a series of test problems. This code is subsequently utilized to analyze the neutron-kinetic processes caused by the nuclide-density perturbation and the neutron-source distortion in the continuous-energy and time phase-space. Encouraging conclusions have been demonstrated by the numerical results.