Geology for Planning and Construction of Deep Geological Repository of Radioactive Waste (Lithuanian Case)

The most part of radioactive wastes in Lithuania has been produced by Ignalina nuclear power plant (INPP). Geological studies for the analysis of Lithuanian geological setting suitability to host the deep geological repository (DGR) had been started at the end of last century. The geological investigations are comprehensive, time consuming and need a high qualification of the experts involved. Potentially suitable geological formations had been selected according to the criteria used in the best international practice. The potentially suitable formations for the DGR construction in Lithuania are the rocks of crystalline basement, lower Cambrian clay, upper Permian anhydrite and lower Triassic clay. A special program has been developed in Lithuania for the purpose of implementing the European Council Directive 2011/70/Euratom of 19 July 2011, establishing the Community framework for the responsible and safe management of spent nuclear fuel and radioactive waste. According to the program the responsibility for DGR project was delivered to INPP in 2019. The geological investigations take a big part of the program and several tasks have been solved already. Sites for the further investigations were identified in 2020, criteria for site exclusion were determined in 2021 and potentially suitable sites were ranked according to the suitability criteria in 2022. However, there are only several results of geological formations material investigations. The lack of such investigations is caused by insufficient financial resources. The material of geological strata should be tested in the natural conditions and new deep boreholes are needed for this purpose.