Iron ore extraction began at the Konrad mine in 1965 and ended in 1976 due to a lack of profitability. During this period, a total quantity of 6.6 million tons of iron ore was mined. The iron ore deposit has a length of approx. 60 km and a breadth of between 8 and 15 km. The iron ore was extracted on several levels at depths of between 850 and 1,200 m.

In 1975, the GSF (Company for Radiation and Environmental Research, today called National Research Center for Environment and Health) was asked by the Federal Government to start with initial scientific investigations into the suitability of the mine as repository for radioactive waste. The first results showed that the mine was principally suited as a radioactive waste repository.

Thanks to many positive properties, it was decided to pursue with further investigation activities. These positive properties were, for example, the depth of the ore horizon, the unusual dryness of the mine and the mainly that the overlying rock is mainly clay which forms a good seal against the shallow sub-surface groundwater horizons.

In 1976, the Federal Office for Research and Technology (BMFT) asked the GSF and the Radiation Research Centre Karlsruhe (KfK) to carry out the relevant investigations. The emphasis of the investigations was to be placed on the geological and mining-related conditions in order to find out if the mine was suitable for the final disposal of radioactive waste that does not develop heat.

As these results, which were presented to the public in a final report in 1982, were again positive, the Physikalisch-Technische Bundesanstalt PTB (national metrology institute providing scientific and technical services), in agreement with the Federal Government, filed a license application in the same year to start a nuclear plan assessment procedure in line with § 9 AtG (Atomic Energy Act).

Between 1982 and 1990, the statutory safety analysis for a radioactive waste repository was effected for the whole Konrad repository system (geological conditions, types of waste, storage technology) and monitored by the state authorities.

In so doing, the specific site conditions and the types and properties of the radioactive waste with negligible heat development, which was to be stored there, were taken into account.

In 1989, the documents required for the planning assessment procedure were handed over to the licensing body, the Environment Ministry of the state Lower Saxony (NMU). In mid-1990, the completeness of the documents was confirmed. Following a first directive of the Federal Environment Ministry (BMU), the public had the possibility to inspect the documents from May 22, 1991 to July 15, 1991. Following a second directive issued by the Federal Ministry, a public hearing was started. Following four more directives on the resumption of the hearing, this hearing was concluded on March 6, 1993. More directives from the BMU followed, however, the official approval in the form of the planning assessment decision was not granted until June 2002.