Recent proposals for a new U.S. standard for high-level waste disposal would
limit the average dose to individuals in the vicinity surrounding a geologic
repository. This would be a new approach to protecting the public from
environmental releases of radioactivity. Heretofore, criteria adopted for
geologic disposal have limited the reasonable maximum exposure to a future
hypothetical individual. Here we present quantitative analyses of the
relation between maximum exposure and vicinity-average exposure, resulting
from future human use of ground water contaminated by radioactive releases
from a repository.
Estimating the vicinity-average exposure would require postulates and
guesses of location and habits of future people. Exposure probabilities
postulated by others show that proposed dose limit to the vicinity-average
individual would be a far more lenient standard than the traditional dose
limit to reasonably maximally exposed individuals. The proposed
vicinity-average dose limit would allow far greater concentrations of
contaminants in ground water than would be allowed by normal standards of
ground water protection. A safety standard that limits vicinity-average
exposure should also include limits on maximum exposure.