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.

Response<br />

248<br />

GEOLOGIC CONSIDERATIONS<br />

Hydrology is discussed as an important factor in selecting the site, qualification <strong>of</strong><br />

the site and assessing the potential for retrievability <strong>of</strong> the waste. The subject is<br />

divided into surface hydrology (draft p. 3.1.47) and groundwater, as a separate topic,<br />

(draft p. 3.1.48-49). The final Statement includes Hydrologic Considerations under Factors<br />

Relevant to Geologic Disposal (See final Appendix B), and then under final Section 5.1.1.2,<br />

as one <strong>of</strong> the most important factors in repository site selection.<br />

Draft p. 3.1.47<br />

Issue<br />

One commenter pointed out that for tectonics and seismicity, the critical point to dem-<br />

onstrate is that the activity pattern is such that future action is not likely to occur dur-<br />

ing the repository's life. This should be expressed in terms <strong>of</strong> probability and acceptably<br />

low probabilities need to be defined. (154)<br />

Response<br />

This is true and hopefully will be done. The difficulty is in assigning acceptable<br />

probabilities to events in the distant future, as well as defining what is acceptable in<br />

terms <strong>of</strong> these-pnrobabilities. One solution is suggested in the second paragraph draft<br />

p. 31.1L.5. Tiistprpobllem is receiving study.<br />

Draft p.- 3.I.48<br />

Issue<br />

The emplacement medium should be <strong>of</strong> an older age, and be overlain and surrounded by<br />

rocks <strong>of</strong> younger age, so that the absence <strong>of</strong> significantly adverse activity for an ade-<br />

quately long time period can be demonstrated. (154)<br />

Response<br />

The requirement thattthe medium be overlain and surrounded by younger rocks may be<br />

unnecessarily restrictive.. For a disposal medium and site location, the stability and<br />

character are more important than whether or not there are younger rocks overlying the dis-<br />

posal material. See the comment for pp. 3.1.1-3.1.3 about the Canadian Shield, for example.<br />

Draft p. 3.1.48<br />

Issue<br />

Regarding jointing, faulting and fracturing, one commenter recommended the addition <strong>of</strong><br />

the following sentence: "They increase the time and cost <strong>of</strong> investigations, complicate the

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

Saved successfully!

Ooh no, something went wrong!