Possible Changes in Radiation Background of the Natural Environment Caused by Coal Mine Activity

Abstract

Highly mineralized waters with salt content up to 200 kg/mJ occur in carboniferous strata in upper Silesia. These waters ojien contain high " 6~a concentration, reaching 400 kBq/mJ, andflow from the surrounding rocks into mine workings and then have to be pumped out to the surface, finally ending in the rivers. Radium-bearing waters of rype A contain significant amounts of barium ions. In these cases radium is easily co-precipitated with barium in the form of BaSO, + RaSO,.The specific radioactivity of such deposits can be as high as I MBq/kg. Radioactive deposits cause elevated gamma radiation levels up to 200 pA/kg and also some elevation of radon daughter concentrations in air. Usually the contamination is limited to small areas lying near streambeds where radium-bearing waters haveflowed. Nevenheless, waste materials from coal mines may cause significant radioactive pollution of the natural environment. In carboniferous strata, so-called radiumbearing waters of rype B occur. These waters contain considerable amounts of sulfates but do not contain L3a2+ ions. In type B waters the concentration of 2 2 6~a reaches 12 k~~/ m ' .In this case there are no chemical conditions for forming highly radioactive deposits.

Natural Radioactivity in Polish Coal Mines: An Attempt to Assess the Trend of Radium Release into the Environment

“…However, these sediments are typically covered by water (brooks and rivers) and may sometimes appear on river banks due to floods or the dredging of watercourses. We estimate that additional doses for inhabitants should not exceed 0.1 mSv/year, which is well below the 1 mSv/year threshold (Skubacz et al 1992;Michalik 2008Michalik , 2011. Nonetheless, due to the long halflives of radium isotopes, particularly 226 Ra, the deposition of Fig.…”

Radium balance in discharge waters from coal mines in Poland the ecological impact of underground water treatment

“…Contrary in radium-bearing waters type B there were more 228 Ra than 226 Ra, the ratio 226 Ra: 228 Ra was from 1:2 up to 1:3. Concentration of 226 Ra in these waters reached 20 kBq/m 3 , while maximum concentration of 228 Ra was as high as 32 kBq/m 3 . These values justify the statement that Upper Silesian radium-bearing waters belong to the waters with highest known radium concentration.…”

“…A method of chemical separation of radium, developed by Goldin [Goldin, 1961], has been modified for liquid scintillation counting [Chalupnik & Lebecka, 1990;Chalupnik & Lebecka, 1993]. Radium is co-precipitated with barium in form of sulphates and this precipitate is mixed with liquid gelling scintillator.…”

“…Waters with high radium concentration occur mainly in the southern and central part of the coal basin, where coal seams are overlaid by a thick layer of impermeable clays [Rozkowski & Wilk, 1992]. These saline waters cause severe damage to the natural environment, owing mainly to their high salinity (sometimes >200 g/l), but also their high radium concentration, reaching 390 kBq/m 3 [Skubacz et al, 1990].…”

Radium removal from mine waters in underground treatment installations

“…In the past, concentrations as high as about 25 kBq m À3 of 226 Ra in discharge waters from coal mines in Upper Silesia were measured and the total discharge was approximately 900 MBq/day (Skubacz et al, 1990). However, regulations demanded that waters with more 226 Ra than 0.7 kBq m À3 must be treated as a waste material with enhanced radioactivity (Decree of the Polish Atomic Energy Agency, 1989).…”