Radon monitoring at the joint research centre – ispra

The object of this study is to measure radon concentrations, both in the soil and buildings of the JRCIspra, in order to compile a radon map indicating areas with low, medium and high concentrations.The monitoring is being performed following the recommendations for the implementation of TitleVII of the European Basic Safety Standards Directive (BSS) concerning significant increase inexposure due to natural radiation sources. For measuring radon both passive and active methods arebeing used. The passive method is a passive track detector in Karlsruhe beakers. The active instrumentused for indoor measurements is a portable radon monitor Alphaguard PQ2000. The study isdivided into two parts: soil air measurements and indoor measurements. For soil air measurements ageological study of the area was performed in order to identify measurement sites and understand therelationship between radon emission and soil type. A thick layer of alluvial and glacial deposits coversthe JRC area with more than 100 meters thickness in some sites. 38 measurement sites were chosen tocover the whole area. The measurements commenced in August 1998 and will be completed after oneyear to take into account seasonal variations, which are critical especially for outdoor measurements.The mean concentration measured so far for every site is less than 10000 Bq/m. For indoormeasurements monitoring in many buildings is being performed both with active and with passivemethods. The mean concentration measured, with the active monitor, for all buildings is less than 50Bq/m in both old and new constructions.The results so far obtained indicate that the JRC territory is not a radon prone area. The thickness,composition and low permeability of superficial deposits may be the reason for low radonconcentrations in this area.