A 3-dimensional finite element method for groundwater flow and containment transport

Harinder Singh Sethi, University of Nevada, Las Vegas


A code was written to model groundwater flow and to solve for contaminant transport in variably saturated porous media using the Finite element method. The numerical code was written in FORTRAN 77. The GWGRID program was used for mesh generation. This numerical model was applied to two nuclear waste sites; Two test cases were run. The first one was the Savannah River Site, located in Aiken, South Carolina (SRS). The SRS has been storing radioactive waste material for several decades. Numerous studies as well as field data for the properties of the surrounding soil and contaminant presence have been conducted. Results of a two dimensional case were compared with the three dimensional case for a period of fifteen years; The second test case was the Yucca Mountain Repository Site (YMP), which is being evaluated as a future site for storing radioactive nuclear-waste. Results from the 3-D simulation were compared to results from a two-dimensional model. This simulation was run for a period of ten thousand years; The purpose for running the 3-D simulation was to get more realistic results than the 2-D calculations. The simulations were mainly run on the Convex and the Cray computer. The results seem to be fairly accurate as compared to the work done at the sites.