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.

Draft p. 3.1.54-62<br />

Issue<br />

275<br />

MULTIBARRIERS FOR DISPOSAL<br />

One commenter stated that since glass is already an adequate waste form, there does<br />

not seem to be any need to emphasize the need for "additional experimentation." The com-<br />

menter also stated that it is unfortunate that calcine, which has more real operating expe-<br />

rience behind it than any other waste form, is given scant praise. (154)<br />

Response<br />

It has not yet been established that glass is a fully acceptable waste form. For exam-<br />

ple, proposed NRC performance criteria, 10 CFR 60, E, (published 5/13/80) would require<br />

reasonable assurance that radionuclides be contained for at least 1000 years. Research is<br />

required to provide this assurance. Other experimentation is that normally associated with<br />

taking a process from a pilot plant status and scaling it up to a full-scale operating<br />

plant.<br />

Concerning calcine, the operating experience has been with wastes that are generally<br />

over a factor <strong>of</strong> 100 less radioactive than commercial HLW and that have a quite different<br />

chemical composition. Granular calcine may be a satisfactory defense waste form for the<br />

long-term but it would probably have to be consolidated by incorporation in a matrix or by<br />

pressing and sintering before it would be a suitable HLW form. These latter processes have<br />

been studied to a limited extent and are discussed in Section 4.3 <strong>of</strong> the final Statement.<br />

Draft p. 3.1.55<br />

Issue<br />

The leach rates <strong>of</strong> spent fuel in typical groundwaters at temperatures to be expected<br />

in spent fuel repositories are more important than leach rates <strong>of</strong> spent fuel in room temper-<br />

ature deionized water. (113-EPA)<br />

Response<br />

The comment is correct and such leach rates are being obtained in the ONWI-sponsored<br />

<strong>Waste</strong> Rock Interactions Technology program at Battelle-Northwest Laboratories. However,<br />

leach rates obtained in room temperature deionized water are not irrelevant. They furnish<br />

a good initial reference point for comparison, and experience has shown that they do not<br />

differ from groundwater by more than a factor <strong>of</strong> ten at the same temperature.

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

Saved successfully!

Ooh no, something went wrong!