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

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48<br />

RADIOLOGICAL ISSUES<br />

it has been suggested in the recent DOE Position Paper to the NRC rulemaking hearings on<br />

nuclear waste storage and disposal (DOE 1980a) that normal variations experienced in natural<br />

background could reasonably serve as an upper bound for allowable standards for the impact<br />

<strong>of</strong> waste management.<br />

Draft p. 3.1.35, First Paragraph<br />

Issue<br />

This paragraph suggests that the fission product problem terminates with the decay <strong>of</strong><br />

90 Sr and 13 7 Cs. While this may be substantially true for the production <strong>of</strong> heat and for<br />

acute radiation hazard, it is not true for the significance <strong>of</strong> the waste as a health hazard.<br />

Doses from 9Tc, 1291, and 13 5 Cs are not negligible over a long time frame. This problem is<br />

repeated in the last sentence <strong>of</strong> the next paragraph. (113-EPA)<br />

Response<br />

The wording "majority <strong>of</strong> the dose": was not intended to imply what the commenter says<br />

it does. Doses from longer lived nuclides, 99 Tc, 1291, and 135 Cs, are small because their<br />

abundance is low. Even at very long times the contribution to dose would be expected to be<br />

relatively small in comparison with that from 23 6 Ra.<br />

Draft p. 3.1.38<br />

Issue<br />

In the early phases, actinide elements, particularly 23 8 Pu and 24 1 Pu, are significant.<br />

Tritium (3H) may also be significant. In the long time frame 135Cs and 14C might also be<br />

significant. (113-EPA)<br />

Response<br />

The paragraphs referred to are describing the division <strong>of</strong> radionuclides into two main<br />

groups; 1) short-lived fission products and 2) long-lived fission products and actinides.<br />

No attempt has been made to determine which actinides are significant with respect to time.<br />

The lists <strong>of</strong> nuclides presented in each paragraph is prefaced by the words "Some <strong>of</strong> the key<br />

isotopes". The significance <strong>of</strong> 3 H and 14C is dependent on the fuel cycle and <strong>of</strong>f-gas treat-<br />

ment system at reprocessing facilities.<br />

Draft p. 3.1.38<br />

Issue<br />

239Pu should be considered a long-lived isotope. (17)

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