Radon and equivalent gamma dose rate variations at different types of antropogenic inhomogeneities Ivan Barnet, Petra Pacherová, Michal Poňavič Czech Geological Survey www.geology.cz Sources of data: Geology – Czech Geological Survey Lidar+topo – State Administration of Land Surveying and Cadastre (licensed) 3D views – www.mapy.cz public server Photos – Mining Museum Příbram www.muzeum-pribram.cz and server www.brdy.org Obecnice Lhota u Příbramě Suchodol Trhové Dušníky Občov Podlesí Dubno Příbram Dubenec 6 )" 10 Háje 5 4 3 Láz Bohutín Nepomuk 2 1 Lešetice Narysov Vysoká u Příbramě" 11 ) )" 12 Fe, kaolin Věšín Sedlice Vranovice Radětice Třebsko Milín Lazsko Modřovice Pb, Ag, U Rožmitál pod Třemšínem Ostrov Vrančice Chrást Tochovice Těchařovice Pečice Bezděkov pod Třemšínem Horčápsko 8 Zbenice " )")9 Vševily Starosedlský Hrádek )" 7 Tušovice Svojšice Chraštice Hlubyně Bukovany Březnice Volenice Nestrašovice granit Hvožďany Kozárovice Locality Pourka 1 Profile across the medieval waste dump (18th century), Fe mining in Cambrian 90 0,18 80 0,16 graywackes, dolerite 70 0,14 vein, fault ) 60 0,12 3 ) - 1 - 50 0,1 Sv.h 40 0,08 µ H ( H Rn (kBq.mRn 30 0,06 Decrease of Rn at 20 0,04 dump material 10 0,02 (permeability) and 0 0 1 2 3 4 5 6 7 8 9 10 water feeded fault , Rn H increase at solid rock Fault marked by increase of H´ 1 3 Locality Dagmar Kaolin surface mining finished at 1935, relatively good-quality 90% of kaolin, use in metalurgy 16 0,18 14 0,16 12 0,14 and ceramic industry ) 0,12 3 ) - 10 1 - 0,1 8 Sv.h 0,08 µ 6 ( H Rn (kBq.mRn 0,06 Fissures on the slope 4 0,04 2 0,02 of Cambrian sediments 0 0 1 2 3 4 5 6 7 8 9 10 Rn H are filled with weathered arcoses=source of kaolin 3 Sv. Trojice shaft 5 Medieval Fe mining (limonite) 6 on the contact of metamorphosed Cambrian sediments and granite, 12 0,25 10 length of drainage adit cca 350 m 0,2 ) 8 3 ) - 1 0,15 - 6 Sv.h µ 0,1 H ( H Rn (kBq.mRn 4 0,05 2 0 0 1 2 3 4 5 6 7 8 9 10 Rn H )" 8 Bezděkov quarry Abandoned granite )" 9 open pit quarry, low quality stone 300 0,3 250 0,25 blocks and debris was deposited ) 200 0,2 3 ) - 1 - around the pit 150 0,15 Sv.h µ H ( H Rn (kBq.mRn 100 0,1 Rn increase can be observed 50 0,05 0 0 on the border of concrete panels 1 2 3 4 5 6 7 8 9 10 Rn H (in red, right part of profile) Zdaboř 35 0,25 Profile across the sinkhole 30 0,2 25 -remnants of mining activities ) 3 ) - 1 20 0,15 - (19-20 cent.) in Cambrian greywackes Sv.h µ 15 0,1 and arcoses) H ( H Rn (kBq.mRn 10 0,05 5 (polymetals Pb, Ag) Příbram district 0 0 1 2 3 4 5 6 7 8 9 10 small waste dumps Rn H Rn increase at the contact with asphalt pavement Vojna )" 12 The first U mine in Příbram area 1200 0,35 (communistic concentration camp 1000 0,3 0,25 1949-1961) ) 800 3 ) - 1 0,2 - 600 Sv.h 0,15 µ Present – exposition of Mining H ( H Rn (kBq.mRn 400 0,1 Museum Příbram 200 0,05 0 0 1 2 3 4 5 6 7 8 9 10 Rn H Lešetice )" 11 )" 12 Conclusions: 1. Different types of inhomogeneities were detected by Rn and H´ variations 2. Rn increase is dependent on the fragment size of the waste dump material . Growing size of fragments „ventilates“ radon into atmosphere, smaller size causes increased radon concentration 3. Level of H´values is dependent on the portion of clayey fraction in the waste dump material 4. Close vicinity of „plate-form insulators – asphalt, concrete panels“ causes Rn increase on its rims 5. Extraordinary high Rn concentrations were found at U mineralized fault even if remediated by inert rock material (metabazalt) – no H´ increase.