Citation

Feng S, Li C, Liu Y, Kang Q. China Saf. Sci. J. 2022; 32(11): 97-104.

Copyright

(Copyright © 2022, China Occupational Safety and Health Association, Publisher Gai Xue bao)

DOI

10.16265/j.cnki.issn1003-3033.2022.11.0284

PMID

unavailable

Abstract

In order to effectively carry out radon pollution control and radon tracing research, the fractal theory and DFN were combined to establish a model of radon migration in fractured medium. In the model, the distribution of fracture lengths was obtained by a double-power law model. The location of fracture centers was determined by the multiplicative cascade process method. The von Mises-Fisher method and the lognormal distribution method were used to model fracture orientations and fracture apertures, respectively. The model was verified by using a test device, and a natural fractured rock mass was analyzed by the model. The results show that the maximum difference between the radon activity concentrations calculated by the model and the test is less than 4%. The average radon exhalation rate of the fractured rock mass is 0. 002 58 Bq/ (m2·s), and interconnected fractures in the rock mass constitute the primary channels for radon migration. The maximum radon flux of the dense fractures is about 3 orders of magnitude higher than that at the sparse fractures. The average radon exhalation rate in fractured medium increases linearly with the fractal dimension, decreases linearly with the length index, and shows a nonlinear increase relationship with the convection velocity. © 2022 China Safety Science Journal. All rights reserved.

Language: zh