A Time-Dependent, Three-Dimensional Neutron Transport Methodology

An improved quasi-static method is applied to the time-dependent, three-dimensional neutron transport equation with explicit representation of delayed neutrons. The relevant equations are derived, and the corresponding implementation of the method is presented. The resulting new code, which uses a threedimensional, discrete ordinates code (TORT) to solve the static fixed-source equations, is tested using transient benchmark problems that are available in the literature. Results obtained with the new timedependent code, named TDTORT, are in satisfactory agreement with the benchmark problem results.