Project "Radiological registration, examination and evaluation of mining relics (Register of Relics)"

Since 1991, the Federal Office for Radiation Protection (Bundesamt für Strahlenschutz, BfS) has been responsible for the determination of natural environmental radioactivity resulting from mining activities in the new federal states as a special task due to German reunification. From 1991 to 1999, the BfS carried out the project "Radiological registration, examination and evaluation of mining relics (Register of Relics)".

BfS project examined mining relics for radioactivity

In this project the uranium mining relics no longer owned by the Wismut GmbH and the relics of historical mining were systematically recorded, examined and radiologically evaluated. The following objects were investigated in detail:

• Milling facilities (facilities for the separation and processing of the usable material through mechanical, chemical or metallurgical processes including premises and operating areas),
• Industrial tailings ponds (ponds for the storage of residues (tailings) and for the purification of liquid process water from milling facilities),
• Waste rock piles (landfills of debris having arisen in the process of mining or mechanical ore dressing operations or of residues from metallurgical processing (slags)),
• Prospects (developments created by mining with shallow depths and small surfaces to explore for ore bodies or exploitable raw materials),
• Galleries (horizontal mining drivings),
• Mine shafts (vertical mining drivings),
• Residual holes, cavities (non-backfilled open pit residual holes or cavities),
• Facilities (non-recultivated operational areas and possibly not decontaminated mining facilities such as ore bins, uranium ore box deposits, water engineering facilities etc.) and
• ore loading areas (areas not located on the premises where uranium ore was reloaded).

In addition to this, it was of particularly important to identify the mining-affected areas in the vicinity of the aforementioned objects, for which it is necessary to take measures to reduce or eliminate the radiation exposure of the population.

Investigations concentrated on suspected sites

As a result of the project, those relics have been identified for which radiation exposures in excess 1 millisievert (mSv) per year cannot be excluded. If necessary, further investigations and remediation measures or restrictions in use must be considered.

In order to make the most efficient use of financial resources, the investigations focused on so-called "suspect sites" (Verdachtsflächen). These are areas where, based on information from mining authorities and geological records, there is a reasonable suspicion of radioactive contamination of the majority of mining objects.

The results of the investigations carried out were stored in the A.LAS.KA and in the technical information system on mining-related environmental radioactivity (FbU). The results were discussed in detail in reports referring on suspected sites. The data and information are available to the authorities of the Laender Saxony, Saxony-Anhalt and Thuringia that are competent for radiation protection implementation.

In parallel to the project "Register of Relics" BfS carried out a measurement programme to investigate radiation exposure due to radon in the air. This programme showed that, although there are clearly enhanced radon concentrations in the vicinity of mining sites are significantly higher than in the natural environment, no large areas are affected. Details are given in the report "Results of outdoor radon measurements in mining areas", BfS-SW-05-09 (in German only).