Modeling Neutron Interaction Inside a 2D Reactor Using Monte Carlo Method

Scientists and engineers have been working for many years to develop accurate approaches to analyzing nuclear power reactors using computer codes that closely model the behavior of neutrons in a reactor core. The Monte Carlo simulation method is capable of treating complex geometries with a high level of resolution and fidelity to model neutron interactions inside a reactor core. With the requirement of accurate modeling in reactor physics and dynamics and great innovation of computer technology, Monte Carlo method is becoming an ever more powerful tool and receiving rising attention. In this study, Monte Carlo method is used to model nuclear interactions between randomly moving neutrons and the fuel material, cladding material and moderator. The code, QualifyingMC, written using Python language develops the neutron diffusion scenario in a two-dimensional car- tesian geometry. To evaluate the performance and accuracy of the simulation, the calcu- lated values of the effective multiplication factor (keff), a key component in characterizing the breeding property of a fission-reactor system, was compared with reference values cal- culated with other codes using the same geometry, materials and boundary conditions. A good agreement within a few percent on multiplication factors was obtained. The neutron flux distribution, another important parameter in a fission-reactor system, as a function of neutron energy is also calculated and compared with the Watt distribution function. A rea- sonable agreement between QualifyingMC and the reference results was obtained.