Subseabed disposal of nuclear wastes

Fine-grained clay formations within stable (predictable) deep-sea regions away from lithospheric plate boundaries and productive surface waters have properties that might serve to permanently isolate radioactive waste. The most important characteristics of such clays are their vertical and lateral unifomity, low permeability, very high cation retention capacity, and potential for self-healing when disturbed. The most attractive abyssal clay formation (oxidized red ciay)covers nearly 30 percent of the sea floor and hence 20 percent of the earth's surface.     

Colloid formation during waste form reaction: implications for nuclear waste disposal

Insoluble plutonium- and americium-bearing colloidal particles formed during simulated weathering of a high-level nuclear waste glass. Nearly 100 percent of the total plutonium and americium in test ground water was concentrated in these submicrometer particles. These results indicate that models of actinide mobility and repository integrity, which assume complete solubility of actinides in ground water, underestimate the potential for radionuclide release into the environment. A colloid-trapping mechanism may be necessary for a waste repository to meet long-term performance specifications.     

Thermodiffusional transport in pelagic clay: implications for nuclear waste disposal in geological media

Thermal gradient experiments in sediment-seawater systems revealed large-scale fluxes of aqueous electrolytic components away from the heat source through thermal diffusion. These findings indicate a need for similar studies in other geological materials of low permeability in order to assess the implications of this phenomenon for various nuclear waste disposal options.     

Prudent practices for disposal of chemicals from laboratories

A recent report of the National Research Council contains guidelines and recommendations for handling and disposing of unneeded chemicals from laboratories. Suggestions are also made for simplifying various procedures imposed by the regulatory agencies with authority over the disposal of laboratory chemicals.     

Strategy for radioactive waste disposal in crystalline rocks

A strategy for waste disposal is proposed in which the repository would be situated in a crystalline rock mass beneath a blanket of sedimentary rocks whose ground-water flow characteristics are well understood. Such an approach exemplifies the concept of multiple barriers to the isolation of radioactive wastes from the biosphere. This strategy has the advantages that (i) ground-water flow within the sedimentary rocks can be investigated and modeled by conventional, well-under-stood theory and technology; (ii) under favorable circumstances, the flow system operates as an active barrier, so that a long migration path and extremely low flow rate to the biosphere can be assured; and (iii) since, in many locations, ground water is nonpotable, the possibility of future human intrusion can be minimized.