REMARKS ON THE RADON GAS RELEASE FROM DUMPS OF URANIUM MINING
J. HARTSCH, J. PINKA
G.E.O.S Freiberg Ingenieurgesellschaft mbH, Freiberg, Germany
Remediation of mining dumps includes a final covering with low permeable material to reduce rain water infiltration and mobilisation of heavy metals. Besides, this a measure to lower the rate of radon emission. To optimise the remediation among other things detailed investigations of radon transport processes are very important. Dumps are complicate constructions characterised by different convective transport paths for the noble gas radon-222, which are strongly influenced by meteorological conditions. So in winter convective radon anomalies occur at the upper dump slope, whereas in summer these anomalies are shifted to the dump foot. The level of radon concentration in the atmosphere due to diffuse release is much lower than that convectively caused. This general picture of radon release from mining dumps can be complicated by structural inhomo-geneities within the dump body. Additionally, overlapping strong effects from nearby open shafts and galleries or such covered by the dump must be taken into consideration in the case of a radiological assessment of measured radon concentrations on a dump and when planning remediation actions.