Testing and Calibration of CDs as Radon Detectors at Highly Variable Radon Concentrations and Temperatures

Abstract

The application of the compact disk (CD) method for radon measurements at mines, caves and other workplaces needs testing under highly variable exposure conditions. We present the results from a blind comparison of CDs exposed in the Laboratory of Natural Radiation (Saelices el Chico, Spain). During the exposure the temperature varied from 6.5 to 24.9 °C (average 12.6 °C) and the 222Rn activity concentrations varied from <10 Bq m−3 to 147 kBq m−3. Good correspondence was observed between the integrated 222Rn activity concentration determined by the reference instruments in the laboratory (122,500 ± 6100 kBq h m−3) and that assessed by analysis of the CDs at a depth 80 µm beneath the front surface (118,000 ± 12,000 kBq h m−3) and at a depth of 120 µm (106,000 ± 12,000 kBq h m−3). The theoretical modeling of the CD response under variable temperature and radon concentration suggested that the small bias is probably due to the time variation of the calibration factor because of the time variations of the temperature.

Investigation of the Performance of Various Low-Cost Radon Monitors under Variable Environmental Conditions

“…The comparison of radon monitors was carried out at the Laboratory of Natural Radiation (LNR) (see Figure 1 ), located at the former uranium mine managed by ENUSA Industrias Avanzadas (Saelices el Chico, Salamanca, Spain) [ 8 ]. This facility has been used since 2000 to carry out several intercomparison exercises and in situ calibrations, addressing the measurement of radon concentration in indoor air, radon exhalation rate from soil, radon concentration in soil, and external gamma radiation dose rate under environmental conditions [ 9 , 10 , 11 , 12 ]. The suitability of this environment for such activities is attributed to the high content of radioactive elements present in the soil, together with the site-specific environmental conditions.…”

Intercomparison of Indoor Radon Measurements Under Field Conditions In the Framework of MetroRADON European Project

“…There is acid drainage in the mine, due to the presence of pyrite in rocks of the site, which pollutes the water [8]. One of the buildings was chosen to house the Laboratory of Natural Radiation (LNR) for the calibration and testing of instruments and detectors for the measurement of natural radiation (see Figure 1) [9,10]. This place has been used to carry out interlaboratory exercises both measuring radon concentration and gamma dose rate under natural environmental fluctuations [4,5,11].…”