Greater confinement disposal

Disposal systems other than those listed, such as greater confinement disposal at depths intermediate between a nearsurface facility and a geologic repository, have been used for some wastes. 

Under current law and regulations, particular disposal systems generally are not required for any waste class, but only certain systems are authorized in law. Disposal systems other than those listed, such as greater confinement disposal at depths intermediate between a near-surface facility and a geologic repository, may be used for some wastes. 

The exposure scenario described in the previous example of domestic uranium mill tailings was used to classify the high-radium residues. The risk and dose assessments indicated a probability of radiation-induced cancer incidence of about 0.6, potential doses in excess of 10 Sv, and a risk index between 50 and 100. Thus, these residues would be classified as high-hazard waste, even under conditions of perpetual institutional control over near-surface disposal sites, and they would require some form of greater confinement disposal well below the ground surface. This conclusion is consistent with recommendations for disposition of these residues (NAS/ NRC, 1995b). 

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