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

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6.84<br />

Because the options for the waste disposal steps from the reactor up to, but not in-<br />

cluding, the transportation alternatives are similar to those for a deep geologic reposi-<br />

tory, the options selected for the reference design are similar for the two concepts. From<br />

that point on, the options selected for the reference ice sheet design are based on current<br />

program documentation for ice sheet disposal.<br />

<strong>Waste</strong>-Type Compatability<br />

Ice sheet disposal by meltdown has been considered primarily for solidified, high-level<br />

wastes from nuclear fuels reprocessing. It would also be applicable for direct disposal <strong>of</strong><br />

spent fuel, without reprocessing, although meltdown would be marginal if the fuel were em-<br />

placed 2 years after reactor discharge. The feasibility <strong>of</strong> meltdown emplacement <strong>of</strong> cladding<br />

hulls and fuel assembly hardware is questionable because the canister heating rate from<br />

radioactive decay would be less than 1/10 that in HLW waste canisters.<br />

For most TRU waste, the heating rate would be less than 1/1000 that expected in HLW waste<br />

canisters, and the meltdown concept does not appear to be feasible. Without blending with<br />

HLW, disposal <strong>of</strong> this waste would be limited to storage in surface facilities on the ice or<br />

emplacement in shallow holes in the ice. For these options, the waste would be buried gradu-<br />

ally in the ice sheet. Contact handled and remotely handled TRU wastes could be handled in a<br />

similar manner. Because <strong>of</strong> volume and cost considerations, TRU wastes are assumed to be<br />

placed in other terrestrial repositories.<br />

<strong>Waste</strong> System Description<br />

The ice sheet waste management system is detailed in Figure 6.1.15. This system concept<br />

is very similar to the very deep hole concept since both spent fuel and the uranium-<br />

plutonium recycle cases could be treated and mined geologic repositories could augment<br />

disposal.<br />

The reference ice sheet disposal concept is not yet well defined. None <strong>of</strong> the three<br />

basic emplacement concept alternatives proposed in the literature (Battelle 1974, EPA 1979,<br />

and ERDA 1976) has been selected as a reference or preferred alternative. <strong>Waste</strong> disposal by<br />

any one <strong>of</strong> these three concepts would be either in the Antarctica or Greenland ice sheets. A<br />

generalized schematic <strong>of</strong> the waste management operational requirements is provided in Figure<br />

6.1.16 (Battelle 1974). The schematic shows the basic system operations (EPA 1979):<br />

* Predisposal treatment and packaging at the reprocessing plant<br />

* Transporting solidified waste from the reprocessing plant or interim retrievable surface<br />

storage facility by truck, rail, or barge to embarkation ports<br />

* Marine transport by specially designed ships during 1 to 3-month periods <strong>of</strong> each year.<br />

* Unloading the waste canisters at a debarkation facility near the edge <strong>of</strong> the land mass<br />

* Transporting over ice by special surface vehicles or aircraft on a year-round basis, as<br />

practicable<br />

* Unloading and emplacing the waste canisters at the disposal site.

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