INTRAVAL PHASE 2, Gorleben test case, interpretation of the Weisses Moor pumping test

Abstract

The Gorleben salt dome is considered as a potential disposal site for radioactive waste. In the safety assessment study, a number of pumping tests are carried out in the geohydrological system surrounding the salt dome. The Gorleben pumping test is simulated in a number of subsequent steps. In the first modelling step the analytical Theis solution is applied. Significant differences between the calculated and observed drawdowns show that the Theis solution assumptions are inappropriate to describe the Gorleben geohydrological system. In the second modelling attempt, the pumping test is simulated numerically with the METROPOL computer code. Geological borelog data and geohydrological profiles and maps are interpreted to obtain information on the aquifer geometry, anisotropy and possible heterogeneity. Under the assumptions of an anisotropic and heterogeneous geohydrological system, simulations of the Weisses Moor pumping test provide calculated drawdowns which match the observed drawdowns reasonably.