Present status on algorithms and benchmark tests for numerical solution of the time-dependent neutron transport equation

Review studies have been made on algorithms of numerical analysis and benchmark tests on neutron transport kinetics computer codes for performing efficient benchmark tests on space-dependent neutron kinetics codes. At present, there are few transport kinetics codes available, compared with the diffusion kinetics codes: the programs are 3 one-dimensional codes and 1 two-dimensional code. Two codes use TASK algorithm and almost of all other codes use algorithms based on the diamond difference method. Exponential difference, exponential extrapolation, coarse mesh rebalancing are adopted in some codes for accelerations. The exponential extrapolation technique is effective particularly in smaller time steps. Benchmark tests for practical problems have not yet been performed. It is desirable to develop methods with a high convergence rate in space, and with a good stability and a high computing speed in time. (auth.)