MEASUREMENT OF RN-222 IN SOIL CONCENTRATIONS IN INTERSTITIAL AIR

Measurements of Rn-222 soil concentrations were made by inserting stai nless-steel sampling tubes into the soil. The samples of the soil inte rstitial air were taken in to pre-evacuated 1 L glass flasks. The glas s flasks are cylindrical and coated with a film of ZnS(Ag). Rn-222 was measured by counting the alpha particles emitted by Rn-222 and its da ughter products, Po-218 and Bi-214, when they reached radioactive equi librium. Measurements of Rn-222 gas concentrations in the soil air int erstices by the method at different depths were used to calculate the diffusion coefficient of the Rn-222 in the soil air. This study has be en carried out for diverse soils. Copyright (C) 1996 Elsevier Science Ltd.