Numerical groundwater flow calculations at the Finnsjoen study site - extended regional area.

摘要

The present report describes modelling efforts of the groundwater flow situation at the Finnsjoen site in northern Uppland, approximately 140 km north of Stockholm. The study forms part of the SKB 91 performance assessment project, and aims at describing the travel times and travel paths from a potential repository for spent nuclear fuel located in crystalline rock, and also to calculate the flux values at repository level. The groundwater flow equations were solved with the finite element technique and made use of the NAMMU-code for stationary calculations in three dimensions. The calculations aimed at identifying a reference case from which the boundary pressures were to be extracted and used as input for future calculations with the HYDRASTAR-code, which is based on the stochastic continuum approach. The study also comprises an analysis to investigate the model sensitivity to the conductivity contrast between rock mass and fracture zones, the sensitivity to the presence of sub-horizontal fracture zones, and the degree of establishment of the discharge area. The fracture zones were modelled implicitly with an averaging technique. (8 refs., 58 figs.) (au). (Atomindex citation 23:079673)