Laboratory apparatus for measuring radon emanation from solids

CIM Bulletin, Vol. 74, No. 833, 1981

R.H. McCORKELL, G. ARCHAMBAULT and M.P. BRAMELD, Bondar-Clegg and Company Ltd., Ottawa, Ontario

The rates, J, at which materials emit radon are of interest in studies of the sources of radon in mines, buildings, soils overburden and other places where it may indicate the location of ore or be a health hazard. Here J values were determined by measuring the radon concentrations by means of scintillation counters or alpha-particle track detectors in chambers in which specimens were sealed. Errors in the measurements due to leakage from the chambers, lack of secular equilibrium in the decay series of the radon measured, or the limited rate of diffusion of radon from powders or within the chambers were shown to be insignificant or could be corrected. Scintillation counter measurements are highly reproducible; track detector measurements also appear useable and may be made on many small samples using small, simple chambers. J measurements were made for uranium ores, drill cores, standard CANMET pulps, concrete and gypsum board. Powdering of ores had little effect on their J values.
Keywords: Radon, Emanation rates, Scintillation counters, Track detectors, Uranium, Exploration, Environmental control.