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Management of Commercially Generated Radioactive Waste - U.S. ...

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6.58<br />

International and Domestic Legal and Institutional Considerations<br />

The island disposal option, like the subseabed and ice sheet options, would require<br />

transporting waste material over the ocean, and the general international implications <strong>of</strong><br />

such transportation are important. Emphasis in this discussion is placed on aspects unique<br />

to island disposal.<br />

Two, possibly complementary, international considerations would have to be studied for<br />

island disposal. On the other hand, an initital motivation for island disposal is that it<br />

could provide an international repository for use by many countries. On the other hand,<br />

the siting <strong>of</strong> a repository on an island over which the U.S. does not have soveriegnty would<br />

require the approval <strong>of</strong> the nation that does.<br />

International concerns could arise from countries in the vicnity <strong>of</strong> a proposed island<br />

repository. For example, if a remote island in the South Pacific were selected for an is-<br />

land repository, nations bordering the South Pacific might feel they were exposed to risks<br />

while receiving little or no benefit. Regardless <strong>of</strong> whether specific treaties were re-<br />

quired, nations adjacent to any island disposal site ould be likely to voice concern and<br />

seek international assurance <strong>of</strong> the safe operation <strong>of</strong> these facilities.<br />

6.1.3.5 Potential Impacts Over Long Term (Postemplacement)<br />

Potential Events<br />

As in land disposal <strong>of</strong> radioactive waste, island disposal would require careful as-<br />

sessment <strong>of</strong> the processes by which the radionuclides could migrate from the containers<br />

through the various barriers to man's environment. Actual island emplacement <strong>of</strong> any quan-<br />

tity <strong>of</strong> such waste could occur only after the completion <strong>of</strong> a program to demonstrate, by<br />

analysis and experiment, the retention capabilities <strong>of</strong> each <strong>of</strong> the natural and man-made<br />

barriers to migration.<br />

<strong>Waste</strong> Encapsulation. The waste form and canisters used for island disposal might<br />

be similar to those used in a mined geologic repository on the mainland. Studies <strong>of</strong> the<br />

specific effects <strong>of</strong> ground-water chemistry in either the freshwater lens or deep saline<br />

zones would provide data for establishing leach rates in the crystalline rock site.<br />

Ground-Water Transport, Freshwater Lens Location. <strong>Waste</strong> emplaced in the freshwater<br />

lens might be exposed to the very slow ground-water circulation within the lens. The ve-<br />

locities would depend on rock permeabilities, porosities, precipitation, and surface hydro-<br />

logy. A simplified conceptual view <strong>of</strong> the potential pathways and barriers is shown in Fig-<br />

ure 6.1.10.<br />

<strong>Waste</strong> in the freshwater lens circulating system might be expected to discharge at the<br />

shoreline. Natural ground-water flow patterns might be affected by thermal convection and<br />

repository construction. Concentrations at the exit zone have not been estimated.

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