Calculating the degree of water saturation of concrete engineered barriers under near surface disposal conditions using HYDRUS

This study documents a methodology and results on a number of different scenarios of water saturation calculations for the concrete engineered barriers (EB) considered for the near surface disposal facility in Dessel. The objective of this study was to determine the saturation history of the concrete engineered barriers after closure of the disposal facility (i.e., interpreted here as the time when the effect of climatic variations (temperature, relative humidity) has come to an end). In view of assessments of the progression of concrete carbonation, known to be a detrimental process to concrete longevity, it is important to know when the concrete saturation has become sufficiently high to reduce the process of carbonation to negligible levels. For this purpose, one-dimensional and two-dimensional unsaturated flow calculations have been carried out using different initial and boundary conditions to cover most scenarios that can occur in a near surface repository.