Fuzzy Optimal Control of Radon Exhalation in Uranium Tailings under Double-Layer Coverage

Abstract

The use of covering material is an important measure to control the radon migration of uranium tailings. Radon diffusion and migration are affected by cover layer parameters, such as diffusion coefficient, overburden thickness, particle size, and ore body width. The radon reduction effect of single-layer mulching is often less than that of double-layer, and the material parameters of the cover layer are uncertain; however, they can be explained by a fuzzy dynamic equation. Firstly, the radon exhalation model is constructed with the radon percolation diffusion and migration method in a double-layer covering. Secondly, a fuzzy target of radon exhalation and a fuzzy constraint model are constructed subject to the total cost and thickness of covering material by a triangular membership function. Lastly, the models are aimed at solving the corresponding extreme value interval of the fuzzy target of radon exhalation by immune genetic algorithm, to reconstruct the fuzzy target, fuzzy constraint, and fuzzy aggregation function, where, ultimately, the optimal radon control decision can be obtained by swarm intelligence algorithm subject to different levels between possibility and importance. An example demonstrates a database of optimal decision-making schemes for double-layer coverage, and flexible management of radioactive pollutants is realized.