Radiation exposure of underground workers in the Konrad mine

The amount of natural deposits of radionuclides such as K-40, U and Th in the Konrad rock, including their decay products, brings about a rise in the level of radioactivity in mines, an enrichment of the air in mines with Rn and Tn, including their short-lived decay products, as well as an increase of radioactivity content in the dust of respiratory air. A report is presented on measurements of this basic radiological load in the Konrad Mine, which leads to an additional exposure of the underground workers to radiation, as compared to the surface workers. The radiation exposure is determined and evaluated from five different points of view. From the evaluation we can infer i.a. 1. that the Konrad Mine, from a radiological point of view, is classifiable within the value range of 9 comparative non-uranium mines; 2. that on the whole, the limit values stated in the radiation protection ordinance regarding radiation-exposed persons (category A) would not be exceeded, in case of an assumed comparable treatment of natural radiation exposure and of artificial radiation exposure expected to result from ultimate disposal; 3. that the additional risk of cancer resulting from radiation exposure underground is negligible in terms of arithmetical figures. (orig./HP)