Variability in dose estimates associated with the food-chain transport and ingestion of selected radionuclides
Dose predictions for the ingestion of /sup 90/Sr and /sup 137/Cs, using aquatic and terrestrial food chain transport models similar to those in the Nuclear Regulatory Commission's Regulatory Guide 1.109, are evaluated through estimating the variability of model parameters and determining the effect of this variability on model output. The variability in the predicted dose equivalent is determined using analytical and numerical procedures. In addition, a detailed discussion is included on /sup 90/Sr dosimetry. The overall estimates of uncertainty are most relevant to conditions where site-specific data is unavailable and when model structure and parameter estimates are unbiased. Based on the comparisons performed in this report, it is concluded that the use of the generic default parameters in Regulatory Guide 1.109 will usually produce conservative dose estimates that exceed the 90th percentile of the predicted distribution of dose equivalents. An exception is the meat pathway for /sup 137/Cs, in which use of generic default values results in a dose estimate at the 24th percentile. Among the terrestrial pathways of exposure, the non-leafy vegetable pathway is the most important for /sup 90/Sr. For /sup 90/Sr, the parameters for soil retention, soil-to-plant transfer, and internal dosimetry contribute most significantly to the variability in the predicted dose for the combined exposure to all terrestrial pathways. For /sup 137/Cs, the meat transfer coefficient the mass interception factor for pasture forage, and the ingestion dose factor are the most important parameters. The freshwater finfish bioaccumulation factor is the most important parameter for the dose prediction of /sup 90/Sr and /sup 137/Cs transported over the water-fish-man pathway.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 5248513
- Report Number(s):
- NUREG/CR-2612; ORNL/TM-8099; ON: DE82016259; TRN: 82-013944
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
FOOD CHAINS
RADIONUCLIDE MIGRATION
MAN
RADIATION DOSES
AQUATIC ECOSYSTEMS
BIOLOGICAL ACCUMULATION
CARBON 14
CESIUM 137
DOSE EQUIVALENTS
DOSIMETRY
ENVIRONMENTAL EXPOSURE PATHWAY
INGESTION
MATHEMATICAL MODELS
STRONTIUM 90
TERRESTRIAL ECOSYSTEMS
TRITIUM
ALKALI METAL ISOTOPES
ALKALINE EARTH ISOTOPES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON ISOTOPES
CESIUM ISOTOPES
DOSES
ECOSYSTEMS
ENVIRONMENTAL TRANSPORT
EVEN-EVEN NUCLEI
HYDROGEN ISOTOPES
INTAKE
INTERMEDIATE MASS NUCLEI
ISOTOPES
LIGHT NUCLEI
MAMMALS
MASS TRANSFER
NUCLEI
ODD-EVEN NUCLEI
PRIMATES
RADIOISOTOPES
STRONTIUM ISOTOPES
VERTEBRATES
YEARS LIVING RADIOISOTOPES
510302* - Environment
Terrestrial- Radioactive Materials Monitoring & Transport- Terrestrial Ecosystems & Food Chains- (-1987)
520302 - Environment
Aquatic- Radioactive Materials Monitoring & Transport- Aquatic Ecosystems & Food Chains- (-1987)