Radiological assessment of sites contaminated due to former mining activities -- The general procedure in Germany

Low level radioactive wastes left from former uranium production and other ore mining and processing has been dumped in certain districts of East German Federal Lands and have to be considered as sources of serious environmental contamination and radiation exposure. In view of the large number and spreading of residues, a multistage procedure with increasing thoroughness of investigations has been developed with the intention to exclude as early as possible non-relevant and to identify those residues which have to be considered as relevant source of environmental contamination and radiation exposure. Following the first two stages of investigations (identification of suspected areas including registration of mining-related objects existing in them and verification of registered objects including screening measurements) the first radiological assessment was carried out and already in this stage about 57% of residues could be classified as ''non-relevant''. The remaining objects were subjected to more detailed investigations. Following these programs the final radiological assessment was carried out to identify the ''relevant'' sites for which remedial measures have to be considered. Up to now the investigations led to the conclusion that the residues of mining, milling and ore processing did not cause a wide-spread radioactive contamination of the environment. Serious contaminations have to be assigned to limited grounds, in particular to mill sites, sites of copper smelteries and places were low level mining waste have been used (e.g. for land filling and covering of roads)