The problem of site selection for low- and intermediate level radioactive waste repository

A presentation of the preliminary geological assessment of potentially favourable environments in Bulgaria for disposal of low- (LLW) and intermediate level (ILW) radioactive waste is made. The total quantity of the processed LLW and ILW for the whole operating period of the Kozloduy Nuclear Power Plant will exceed 178 000 m3. The first step in tackling the problem associated with the radioactive waste disposal has been the development of the Concept for National Radioactive Waste Repository in 1991-1993 by an inter-disciplinary team. As a result of the study performed during the development of the Concept, three geological formations and two mines have been identified for further investigations: Neogene clayey deposits, Low Cretaceous marls, loess sediments, Koshava mine (Neogene gypsum sediments) and Smolyanovtsi uranium mine. The sites were analysed using geological, seismotectonical, geomorphological, hydrogeological, engineering, geological and socio-economical criteria. On the basis of the system analysis it was established that the sites can be divided into three groups according to the degree of preference: 1) Low Cretaceous marls; 2) loess sediments; 3) Miocene clays, Koshava and Smolyanovtsi mines. These assessments are based mainly on explorations and research carried out for other purposes, so they are preliminary and need additional argumentation. 1 ref