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

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H.3<br />

number <strong>of</strong> MPI in the environment versus time. The potential hazard measure (PHM) (Gera and<br />

Jacobs 1972) is an index that is proportional to the quantity <strong>of</strong> radionuclides buried as a<br />

function <strong>of</strong> time and modified by the probability that this material will reach man. The<br />

hazard index (HI) (Claiborne 1975) is a quantity that is proportional to the specific toxic-<br />

ity <strong>of</strong> a radionuclide. It was formulated to assess the benefits <strong>of</strong> actinide removal from<br />

high-level waste. The hazards available index (HA) (Bruns 1976) is a modification <strong>of</strong> the<br />

hazards index that includes a pathways transport efficiency. It has been used to compare<br />

the hazard from Purex waste to the hazard from fallout. The isolation time (T) (Voss and<br />

Post 1976) is the time radionuclides must be held to limit their concentration in ground<br />

water to one MPC. It was introduced to characterize the effectiveness <strong>of</strong> geologic isolation<br />

in restraining the transport <strong>of</strong> radionuclides via the groundwater transport path. The rela-<br />

tive toxicity index, RTI (Haug 1977, Hamstra 1975, Haug 1976, Cohen and Tonnessen 1977,<br />

Rochlin 1977), is the ratio <strong>of</strong> the hazard indices <strong>of</strong> nuclear waste to uranium ore. This<br />

index has been generalized to compare to toxicity <strong>of</strong> nuclear waste to the toxicity <strong>of</strong> other<br />

naturally occurring toxic elements.<br />

Although each hazard index has merit for a particular set <strong>of</strong> conditions,the provision<br />

<strong>of</strong> simple measures <strong>of</strong> hazard can confuse rather than clarify. For this reason hazard<br />

indices are infrequently used in this Statement and dose and associated health effects are<br />

presented instead.

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