The methods that might be used to bury radioactive waste in the deep ocean, and their likely effect on the sediment barrier, have been the subject of an international research program performed during the last ten years. This paper reviews the geotechnical aspects of deep ocean disposal and discusses how far the research performed has gone towards providing the information needed to assess this form of disposal.
Considerable progress has been made during the course of the international program towards understanding the processes involved in the emplacement of heat generating waste (HGW) into the deep ocean bed and the subsequent interactions between the waste and the sediments. These processes do not appear to have a deleterious effect on the barrier properties of the sediments, and it is concluded that it is likely that HGW could be emplaced in the deep ocean in such a way that the seabed would provide an effective containment for the radionuclides. However, if it were decided to continue research on deep ocean disposal, considerable further effort would be needed to accurately quantify all these processes. Moreover, the extrapolation of the results of theoretical studies and laboratory simulations to the deep ocean is hindered by the lack of reliable geotechnical data for the sediments at the deep ocean study areas; for example, because no in-situ measurements have been made, shear strength data are limited to the depth of the longest cores (35 m) and their accuracy reduced by the indeterminate effects of sample disturbance.