Development of a hybrid stochastic/deterministic method for transient, three dimensional neutron transport

This research develops an improved methodology (and corresponding code) for solving the time-dependent, 3-d Boltzmann Transport Equation with explicit representation of delayed neutrons. These improvements are incorporated in a modified version of the code TDKENO, entitled TDKENO-M. Specifically, these improvements are: (1) incorporate the improved quasistatic methodology into an existing quasistatic framework, specifically, include the flux shape derivative in the fixed source term instead of being neglected, also, compute the point kinetics parameters deterministically by their inner product definitions; (2) incorporate a hierarchy of three different integration time intervals for the numerical solution of the coupled set of ordinary differential equations, the shape function is assumed to vary linearly over the largest time interval, the second large time interval is used for determining the point kinetics parameters, finally, the smallest time step is used for solving the point kinetics equations; (3) apply TDKENO-M to benchmark problems to determine the accuracy of the method, particularly, TDKENO-M is applied to 1-D and 3-D benchmark problems to evaluate its capabilities; (4) combine input requirements into a single input file so that TDKENO-M is less cumbersome to execute; (5) develop the ability to restart a calculation at an intermediate problem time; and (6) develop a user-friendly manual for using TDKENO-M which describes in detail the input requirements as well as the output files, subroutines, modules, and the calculational flow.