Application of the unsymmetric Lanczos method to radionuclide decay-chain transport in porous media

Using either a finite element or finite-difference method to solve radionuc lide waste transport problems involving advection, dispersion, decay and tr ansformation simultaneously is numerically complicated. Most applications h ave used only one-dimensional transport and extending this approach to high er-dimensional problems is a formidable task. This paper uses the ULR metho d to reduce the size of the semi-discretized linear system and enables this extension. The development of this application includes a new method for c hoosing a common starting vector for all species in order to ensure the ULR method is convergent. The results of numerical simulations of application of this method to practical field contaminant transport problems show the e fficiency of the method. Copyright (C) 1999 John Wiley & Sons, Ltd.