Radionuclide disequilibria studies for investigating the integrity of potential nuclear waste disposal sites: subseabed studies

This study of subseabed sediments indicates that natural radionuclides can be employed to define past long-term migration rates and thereby evaluate the integrity of potential disposal sites in ocean sediments. The study revealed the following conclusions: (1) the sedimentation rate of both the long and short cores collected in the North Pacific is 2.5 mm/1000 yr or 2.5 m/m.yr in the upper 3 meters; (2) the sedimentation rate has been rather constant over the last one million years; and (3) slow diffusive processes dominate within the sediment. Reworking of the sediment by physical processes or organisms is not observed