Ispitivanje brzine ekshalacije radona: uticaj sprašenosti i vlažnosti uzorka

Abstract

U radu je merena ekshalacija radona iz bigra iz Niške Banje poznatom po povišenoj koncentraciji 226Ra. Bigar zbog svoje velike poroznosti i visoke koncentracije radijuma je idealan materijal za testiranje parametara od kojih zavisi brzina ekshalacije. U radu je razmatrana zavisnost ekshalacije u odnosu na vlažnost kao i na sprašenost uzorka. Brzina ekshalacije je merena metodom zatvorene komore, a sama koncentracija radona aktivnim uređajem. Dobijeni rezultati ukazuju da brzina ekshalacije raste sa povećanjem vlažnosti uzorka i smanjenjem veličine zrna.

In this contribution, radon exhalation rate from travertine originating from Niška Banja, Serbia was measured. This particular travertine, with a high 226Ra concentration and high porosity, is ideal for testing various parameters that can influence radon exhalation rate. The radon exhalation rate was investigated for different sizes of grains. Grain sizes were dived into 4 groups: 1) 2.1 - 1.6 mm, 2.) 1.6 - 1.2 mm, 3.) 1.2 - 0.7 mm i 4.) < 0.7 mm. Influence of the humidity on radon exhalation rate was also investigated. Samples with the smallest grain size were exposed to 3 different levels of humidity (dry sample, and two samples in which water content was around 10% and 20% of the mass of dry sample. An accumulation chamber method with an active device RTM1688-2 was used to estimate radon exhalation rate from continuous measurement of radon in the chamber. Obtained results indicate that radon exhalation rate is increasing with an increase of humidity of the sample and with an decrease of grain size.