NIOSHTIC-2 Publications Search
The Effects of Moisture on Radon Emanation. Including the Effects on Diffusion.
Thamer-BJ; Nielson-KK; Felthauser-K
NTIS: PB/83-136358 :213 pages
Radon emanation coefficients of 0.02 to 0.55 were measured at moisture contents ranging from dry to saturation in 18 different ores. The emanation coefficients rose from a minimum when dry to a plateau usually starting at 5 to 20 percent of saturation. A model, using measured pore-size distributions, suggested that the radium mineralization may be confined to annular layers about 0.02 Micrometer thick around pores. Radon's diffusion coefficient was determined as a function of moisture. The techniques involved comparing a disk's exhalation as a function of time whether or not the disk had a distributed source. The model was free of approximations and included the effects of porosity and adsorption. An increase of diffusion coefficient with moisture for one or two ores was explained in terms of a model's equation for the diffusion coefficient in terms of both volume and surface diffusion. Radon's adsorption coefficient was determined on a uranium ore.
CP; Final Contract Report;
NTIS Accession No.
Ford, Bacon & Davis Utah, Inc.
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division