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.

5.5<br />

5.1.1.2 Generic Basis for Repository Site Selection<br />

This section presents the generic basis for repository site selection and the design<br />

<strong>of</strong> the repository. Characteristics most desirable for site selection and how they relate<br />

to design are discussed. Criteria necessary for development <strong>of</strong> siting criteria and reposi-<br />

tory waste form design are presented.<br />

The most important site-selection factors can be derived from the six geologic con-<br />

siderations given in Section 5.1.1.1. In general, the most important factors are the hydro-<br />

logic regime, the tectonic regime, the multibarrier concept, and the thermal, physical and<br />

geochemical properties <strong>of</strong> the host rock. For any particular location, site-specific con-<br />

siderations peculiar to that site might be different and would take precedence.<br />

The site-selection process will proceed in stages as described below. Program scien-<br />

tists will select regions, areas, and sites, in that order, by their meeting defined<br />

requirements. Each stage <strong>of</strong> the site-selection process will add to the geologic information<br />

available for the preceeding stage and will better define uncertainties. Therefore, the<br />

site-selection process will yield progressively more significant data; that is, each phase<br />

<strong>of</strong> the process will further characterize site-specific considerations, thus reducing<br />

uncertainties.<br />

The following criteria are suggested for repository site selection to assure that the<br />

natural barriers function as planned:<br />

1. The repository site shall be located in a geologic environment with geometry<br />

adequate for repository placement.<br />

2. The repository site shall have geologic characteristics compatible with waste<br />

isolation.<br />

3. The repository site shall have subsurface hydrologic and geochemical characteris-<br />

tics compatible with waste isolation.<br />

4. The repository site shall be located so that the surficial hydrologic system, both<br />

during anticipated climatic cycles and during extreme natural phenomena, shall not<br />

cause unacceptable adverse impact on repository performance.<br />

5. The repository site shall be located in a geologic setting that is known to have<br />

been stable or free from major disturbances such as faulting, deformation and<br />

volcanic activity for long time periods.<br />

6. The repository site shall be located in an area that does not contain desirable<br />

or needed mineral resources, or to the extent presently determinable, resources<br />

that may become valuable in the future.<br />

Regional studies <strong>of</strong> stratigraphy and structural geology will be conducted to aid in<br />

site selection. Stratigraphy is the general characterization <strong>of</strong> the sequence <strong>of</strong> rock types<br />

both vertically and laterally. Structural geologic studies determine orientation <strong>of</strong> the<br />

rock units in space, direction <strong>of</strong> dip, configuration <strong>of</strong> folds, and the characteristics and<br />

attitudes <strong>of</strong> faults, joints, and other discontinuities. Adequate description <strong>of</strong> the

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

Saved successfully!

Ooh no, something went wrong!