Implementation of a temporal quadratic expansion space-time dynamics method

A new space-time dynamics method, the temporal quadratic expansion nodal Green's function method (TQE/NGFM), was verified numerically. A special iteration scheme was designed to calculate the fluxes at two time levels within one time step. The TQE/NGFM program and the standard transient nodal Green's function method (TNGFM) program, in which a fully implicit approximation was used, were used to solve light water reactor benchmark problems. In the two-dimension TWIGL problem, the computing time using TQE/NGFM is about one fifth of that using TNGFM with approximately the same precision. The comparison shows that the temporal quadratic expansion space-time dynamics method is an effective and advanced method.