Geological and engineering geological settings of the radioactive waste repository Novi Han, Lozen Mountain, Bulgaria

The Repository for Radioactive Waste (RAW) Novi Han of the Russian “Radon” type was built in the middle of 60-es, last century, in the Lozen Mountain near Sofia. Unconditioned wastes from medicine, military sources and scientific research activities are stored in it. The repository site has not been selected after detailed geological, hydrogeological and engineering geological investigations including safety assessment procedures. Such investigations were realized in the early 90-es by institutes of the Bulgarian Academy of Sciences. Later, in 2000–2002 the studies of the site have been enlarged with the authors` participation. These newly performed investigations have taken into account the requirements of the International Atomic Energy Agency (IAEA) documents. In the paper the results concerning the engineering geological and hydrogeological settings of the site are presented. Its geological and tectonic conditions are discussed as well. The data will be used for future analyses of impact of the Novi Han repository over the environment including radiological safety assessment.