Complementary system for long term measurements of radon exhalation rate from soil

Abstract

A special set-up for continuous measurements of radon exhalation rate from soil is presented. It was constructed at Laboratory of Radiometric Expertise, Institute of Nuclear Physics Polish Academy of Sciences (IFJ PAN), Krakow, Poland. Radon exhalation rate was determined using the AlphaGUARD PQ2000 PRO (Genitron) radon monitor together with a special accumulation container which was put on the soil surface during the measurement. A special automatic device was built and used to raise and lower back onto the ground the accumulation container. The time of raising and putting down the container was controlled by an electronic timer. This set-up made it possible to perform 4-6 automatic measurements a day. Besides, some additional soil and meteorological parameters were continuously monitored. In this way, the diurnal and seasonal variability of radon exhalation rate from soil can be studied as well as its dependence on soil properties and meteorological conditions.

Outdoor 222Rn behaviour in different areas of Slovakia

“…The correlation between obtained radon exhalation rates E S and RAC in the soil air at a depth of 0.8 m is better (R 2 = 0.99) than the correlation between radon exhalation rates and specifi c activity of lie within the range of the E S values obtained from direct measurements published in [23]. In general, radon exhalation rate from the soil exhibits diurnal and seasonal variations.…”

“…Usually, the lowest values of E S are found during the winter months and the highest during the summer. A linear relationship between radon exhalation rate and outdoor temperature was found by Mazur and Kozak [23] for the temperature range from -5 to +25°C. It could be assumed that the exhalation rates obtained by us for individual localities based on summer measurements of outdoor radon are approximately twice as high as the yearly average.…”

“…This month was chosen because, during summer, the surface layer of the soil is not affected by cold and humidity as much as during other seasons of the year. Hence, the relationship between radon exhalation rate and radiation characteristics of the soil should be more pronounced [23].…”

Investigation of the influence of chamber construction parameters on radon exhalation rate

“…Having the detailed characteristics of the studied ground, one can assess the expected value of radon exhalation rate E Rn [Bq·m −2 ·s −1 ] using the following formula [15]: (3) where:  -the radon emanation coeffi cient in soil [-], A Ra -the radium concentration in the soil [Bq·kg …”

“…Some authors described this kind of measurements but the presented results regarded only a single or short-term measurements of radon exhalation rate from soil [10][11][12][13][14]. The study of the relationship between radon exhalation rate from soil and meteorological conditions has been carried out by Mazur and Kozak [15] and Ferry et al [16] The authors used an automatic device for long-term measurements of radon exhalation rate.…”