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