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

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Draft p. 3.6.4<br />

Issue<br />

361<br />

ALTERNATIVE DISPOSAL CONCEPTS<br />

It is noted here that containment is required for 250,000 to 500,000 years. This<br />

appears inconsistent with current proposed criteria, which would require that the wastes<br />

maintain their integrity until they reach a radioactivity level comparable to ore bodies.<br />

This would entail about 500 to 600 years <strong>of</strong> storage, not 500,000. (124)<br />

Response<br />

In establishing early criteria, ultra conservatism was used. It is felt that any<br />

radioactive material entering the water column should have lower radioactivity than natural<br />

ore bodies, and therefore a time much longer than 500 years is needed. The figure <strong>of</strong><br />

500,000 years may, however, be too large.<br />

Draft pp. 3.6.4, 3.6.7<br />

Issue<br />

Under "Water Column," there is a statement that bottom currents are slow and uniform.<br />

However, in Section 1.3.6 the DEIS says bottom currents are weak and variable. This incon-<br />

sistency should be corrected. (113-EPA)<br />

It is stated that: 'Bottom currents in the MPG areas <strong>of</strong> the North Pacific are gen-<br />

erally weak and variable.' A reference should be provided. How weak and variable bottom<br />

currents affect emplacement, radionuclide migration, heat transfer, etc.,, should be dis-<br />

cussed. (208-NRC)<br />

The bottom flow is not uniform and plate-like. The mean flow is thought to be slow,<br />

but there is a transient component that is related principally to the tides. Within about<br />

5 m <strong>of</strong> the bottom there is a boundary layer that is thought dynamically analogous to the<br />

lowest 2 km in the atmosphere. See Weinbush, M. and W. Muck (1970): The Benthic Layer in<br />

The Sea, Vol. 4, pt. 1, A. E. Maxwell, Editor. (23-DOC)<br />

Response<br />

The discussion on water columns has been revised and condensed for the final State-<br />

ment; the inconsistancy noted above no longer appears. Bottom currents are weak and vari-<br />

able. (See also Bishop 1975, and Talbert 1976.)<br />

Draft p. 3.6.5<br />

Issue<br />

It is noted that the waste should decay to innocuous levels. It would appear appro-<br />

priate to define innocuous levels. (124)

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