A Research Study on the Radiological State of Building Material and the Risk Assessment

The objective of the present study is focused an the assessment of the radiological risk from building materials used in Attica region, Greece. Bricks and concrete com- monly used in Attica region have been studied for both natural radionuclide content and radon exhalation. The high-resolution gamma-ray spectroscopy technique, as well as radon exhalation measurements, have been employed. The technique used for the measurements of the radon exhalation is called "continuous accumulation- counting" method and has been described in detail by the authors in earlier pub- lications. This measurement technique is based on the continuous air flow through a sealed chamber containing the sample and through a scintillation counter (Lucas cell). The counting is continuous as well.

A prototype radonmeter for seismic surveillance

A new 222Rn monitoring prototype has been designed, assembled and tested at the Istituto Nazionale di Geofisica (ING) specifically addressed to seismic surveillance tasks, exploiting environmental monitoring, etc. It operates with an a scintillation technique (photomultiplier + Lucas Cell) coupled with a water input system, that lets continuous dehumidified gas flow, stripped from groundwater under monitoring. Several laboratory tests have been carried out to check the stability and versatility of the system; moreover statistical tests have been accomplished on several data sets obtained with an 241Am radioactive standard source, to check stability of the photomultiplier. A customised water flow system has been developed to perform both the highest efficiency and lowest influence of external noise parameters. This new prototype is very cheap and will be integrated within the new multiparametric geochemical monitoring system GMS II, that is currently being developed at ING, specifically designed for geochemical surveillance of seismic events.

A Method for the Measurement of the Emanation Factor for 222Rn in Small Samples of Porous Materials

A method to determine the emanation factor for 222Rn in small samples of soils and building materials is proposed. The method is based on the principle of enclosing the sample to be tested in a hermetically sealed modified Lucas cell, designed and built in our laboratory, and subsequently measuring the radon concentration growth in the cell. The method has been tested for a total of 27 samples with different properties, including soils, building materials and phosphate fertilisers, which were previously evaluated for their physical properties and measured by gamma spectrometry to determine their radium activity concentrations.