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

Using either a nite element or nite-di erence method to solve radionuclide waste transport problems in- volving advection, dispersion, decay and transformation simultaneously is numerically complicated. Most applications have used only one-dimensional transport and extending this approach to higher-dimensional problems is a formidable task. This paper uses the ULR method to reduce the size of the semi-discretized linear system and enables this extension. The development of this application includes a new method for choosing 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 eld contaminant transport problems show the e ciency of the method. Copyright