Using Pedotransfer Function (PTF) analysis in the assessment of the parameters of potential radionuclide transport through the vadose zone of PRAW “Novi Han” – an initial stage of a model case study

The Repository for Radioactive Waste in Novi Han, Lozen Mountain (Bulgaria), dates from the early 1960s. In the present study, the complex geoenvironmental setting of the repository site was analysed from the viewpoint of assessment of potential radionuclide migration from the repository to the geosphere. Thus, components of the mass transport field were elaborated as a part of a conceptual model. In connection with this, a detailed characterization of the subsurface, especially of the vadose zone around the repository, was performed. The fractions of sand, silt and clay based on the grain-size distribution curves of samples from the different hydrogeological units gathered on the site of RAW-Novi Han were implemented in the ROSETTA program, and the respective hydraulic parameters were determined. As a result, the entire vadose zone was hydraulically determined.