In order to achieve long-term stability and reliability of the covered uranium mill tailings(UMTs)pond beach face, simulation studies were carried out applying a self-made experimental instrument of radon exhalation for soil overburden on the beach, aiming at a UMTs pond in humid location of southern China, to verify radon adsorption performance of calcium lignosulfonate(CaLS)through adsorption experiments.Experiments on enhanced radon retarding performance of CaLS-stabilized red clay were carried out.Effect of CaLS-stabilized red clay as soil overburden for radon retardation on the beach surf...