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

5.82
Seventy-year whole-body dose commitments have been calculated for the maximum individ-
ual using the data of Tables 4.4.3 and 9.3.34 in DOE/ET-0029, the methods described in
Appendix D and the following assumptions. For cases in other than a salt repository,
aquatic food is taken from, and recreational activities occur near, the 2.8 m /sec stream of
water from the repository (this assumption is perhaps overly simplistic since the stream
flows for only one year and little time is available for an aquatic ecosystem to be estab-
lished). Drinking water is taken from the river downstream from the point of contamination
entry (the majority of the regional population resides down stream from the repository and
the presumed point of entry of the stream). Contaminants in farm products and ground con-
tamination doses were determined based on irrigation of land with water from the river. In
the case of a repository in salt it was concluded that the 2.8 m3/sec effluent stream would
be so laden with salt that no fresh-water biota would be present and that the maximum indi-
vidual would derive his aquatic food from the river as opposed to the small stream.
Doses to the maximum individual are presented in Table 5.5.7. Population doses were
also calculated on the basis of contamination of water in the R river. Seventy-year dose
commitments to the maximum individual and the regional population were calculated for 1000,
100,000 and 1,000,000 years after closure of the repository.(a) Doses to the regional
population are presented in Table 5.5.8. Doses to other regions and for the breach in the
year of repository closure may be found in DOE/ET-0029.
The range of population dose for the flooding and faulting event 1000 years after clo-
sure amounted to 8.8 x 104 to 1.7 x 105 for spent fuel and reprocessing wastes, respectively.
Using the range of 100 to 800 health effects per million man-rem, the calculated total number of
health effects attributable to this event, if it occurred as postulated, would be 9 to 140 depend-
ing on fuel cycle.
The probability of a fault intersecting the repository in a typical bedded salt basin
such as the Delaware Basin has been estimated by Claiborne and Gera (1974) to be
TABLE 5.5.7. 70-Year Whole-Body Dose Commitment to Maximum Individual--
Repository Breach by Faulting and Flooding, rem
Time of Event Salt Media Non-salt Media
Closure + 1,000 Years
Spent Fuel 3.0 x 10-1 9.7
Reprocessing Waste 5.5 x 10 -
Closure + 100,000 Years
1.5 x 101
Spent Fuel 3.7 x 10 - 1 8.6
Reprocessing waste 6.7 x 10
Closure + 1,000,000 Years
- 2
1.5
Spent Fuel 1.8 x 10-1 4.3
Reprocessing waste
- 2
2.2 x 10
- 1
4.5 x 10
(a) Calculations were presented in the Draft DOE/EIS 0046-D for a stream breach in 2050.
In deference to comments on the unreasonableness of this event, it is not presented
here; detection would be almost certain and mitigation of affects possible. At
1000 years after closure the unrecognized contaminated stream does not seem
unreasonable.