23.04.2013 Views

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

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

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

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

6.49<br />

Various options to be considered for island disposal are summarized in Figure 6.1.7, with<br />

options for the reference concept designated. Details on the bases for selecting reference<br />

concept options are covered in various documents listed in Appendix. M.<br />

Because system options for island waste disposal beginning with the reactor and including<br />

steps up to the transportation requirements are similar to those for mined geologic reposi-<br />

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

that point on, the selected options are based on current program documentation.<br />

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

An island repository could handle all wastes from the uranium and plutonium recycle case,<br />

and from the once-through cycle.<br />

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

The reference island repository design is based on the concept discussed in Section<br />

6.1.3.1 and the waste disposal cycle options identified above. The fuel cycle and process<br />

flow for the reference concept are shown in Figure 6.1.8. The reference system assumes the<br />

transport <strong>of</strong> all spent fuel, HLW and transuranic wastes to the island sites.<br />

The waste forms and emplacement concept <strong>of</strong> canistered waste for island disposal would be<br />

the same as those for conventional mined geologic disposal discussed in Chapter 5.<br />

Predisposal Treatment and Packaging. The predisposal treatment <strong>of</strong> waste for the island<br />

disposal concept would be identical in most respects to the predisposal treatment <strong>of</strong> waste<br />

for mined geologic repositories. Chapter 4 discusses the predisposal systems for both spent<br />

fuel and HLW common to all <strong>of</strong> the disposal concept alternatives.<br />

Geologic Environments. The geohydrologic regime <strong>of</strong> an island, as diagrammed in Figure<br />

6.1.9, comprises a self-contained freshwater flow system (called the freshwater lens because<br />

<strong>of</strong> its general shape), floating on a sea-fed, saline ground-water base. There are two possible<br />

locations for the repository--in the lens <strong>of</strong> freshwater circulation and in the deep,<br />

near-static saline ground water - shown as A and B in the figure.<br />

Geographically, three classes <strong>of</strong> island have been identified:<br />

* Continental Islands - located on the continental shelves and including igneous, metamor-<br />

phic, and sedimentary rock types<br />

* Oceanic Islands - located in ocean basins and primarily <strong>of</strong> basaltic rock <strong>of</strong> volcanic<br />

origin<br />

* Island Arcs - located at margins <strong>of</strong> oceanic "plates", primarily <strong>of</strong> tectonic origin, and<br />

frequently active with andesitic lavas.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!