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

D.1.1.5 Ingestion of Food Crops
D.3
Food crops may become contaminated by deposition of radionuclides directly from the air
or from irrigation water upon the plant su.-faces or by radionuclides taken up from soil pre-
viously contaminated via air or water. Many factors must be considered when calculating
doses via ingestion of these foods. These factors account for the movement of radionuclides
from release to the receptor and form a complex sequence (Baker et al. 1976).
Equations used to calculate such doses are given in two parts: the first accounts for
direct deposition onto leaves and translocation to the edible parts of the plant, while the
second accounts for long-term accumulation in the soil and root uptake.
For sprinkler irrigation and for deposition of airborne materials both parts of the
equation are used, while only the part dealing with root uptake is required for ditch irri-
gation. Tables of transfer factors and plant uptake factors are stored in files in the pro-
gram FOOD (Baker 1977). The program can handle nine crops and their pathways to man. The
output of the program lists the concentrations of radionuclides in the food crops and the
fraction of the concentration due to each part of the equation (i.e., leaf or root). It
also lists the dose to each organ from each nuclide/crop combination, with a summary of
total doses from all crops and nuclides combined.
The nuclides 3H and 14 C are treated as special cases in the FOOD program. The con-
centrations in the initial environmental media (air or water) are calculated on the basis
of the specific activity of the nuclide in the naturally occurring stable element.
D.1.1.6 Ingestion of Animal Products
Five products--milk, eggs, beef, pork, poultry--are included in the FOOD program. The
concentrations in the animals' feed are first calculated as discussed above for human food
crops.
The equation, the quantities of animal feed and water consumed, and a listing of the
transfer factors (fraction of each day's intake appearing per liter of milk or kilogram of
eggs or meat) are given by Baker et al. (1976). The output of FOOD lists doses to various
organs by nuclide and food type and summarizes total dose from all nuclides in milk, eggs,
and meat (beef, pork and poultry).
D.1.1.7 Accumulated Doses from Foods
The computer program PABLM was written to calculate cumulative radiation dose to people
from the ingestion of food. A total of eight food categories (leafy vegetables, other
above-ground vegetables, root vegetables, fruit, grain, eggs, milk, and meat) can be
selected with corresponding consumption rates, growing periods, and irrigation rates or
atmospheric dilution parameters assigned by the user. Radionuclides may be deposited by
water used for irrigation or directly from the atmosphere onto vegetation or the ground for
the expected operating life of the facility. Dose commitments to the whole body and six
internal organs from 186 radionuclides can be accumulated for a specified dose period. However,
computer core space limitations restrict input considerations to only four organs