Soil-to-Plant Concentration Ratios for Assessing Food Chain Pathways in Biosphere Models

Napier, Bruce A. ; Fellows, Robert J. ; Krupka, Kenneth M.

Pacific Northwest National Laboratory (U.S.)

关键词: Biosphere;    Soil Chemistry;    Bioavailability;    12 Management Of Radioactive Wastes, And Non-Radioactive Wastes From Nuclear Facilities;    Waste Disposal;   

DOI  :  10.2172/926965
RP-ID  :  PNNL-16741
RP-ID  :  AC05-76RL01830
RP-ID  :  926965

美国|英语

来源: UNT Digital Library

【 摘 要 】

This report describes work performed for the U.S. Nuclear Regulatory Commission’s project Assessment of Food Chain Pathway Parameters in Biosphere Models, which was established to assess and evaluate a number of key parameters used in the food-chain models used in performance assessments of radioactive waste disposal facilities. Section 2 of this report summarizes characteristics of samples of soils and groundwater from three geographical regions of the United States, the Southeast, Northwest, and Southwest, and analyses performed to characterize their physical and chemical properties. Because the uptake and behavior of radionuclides in plant roots, plant leaves, and animal products depends on the chemistry of the water and soil coming in contact with plants and animals, water and soil samples collected from these regions of the United States were used in experiments at Pacific Northwest National Laboratory to determine radionuclide soil-to-plant concentration ratios. Crops and forage used in the experiments were grown in the soils, and long-lived radionuclides introduced into the groundwater provide the contaminated water used to water the grown plants. The radionuclides evaluated include 99Tc, 238Pu, and 241Am. Plant varieties include alfalfa, corn, onion, and potato. The radionuclide uptake results from this research study show how regional variations in water quality and soil chemistry affect radionuclide uptake. Section 3 summarizes the procedures and results of the uptake experiments, and relates the soil-to-plant uptake factors derived. In Section 4, the results found in this study are compared with similar values found in the biosphere modeling literature; the study’s results are generally in line with current literature, but soil- and plant-specific differences are noticeable. This food-chain pathway data may be used by the NRC staff to assess dose to persons in the reference biosphere (e.g., persons who live and work in an area potentially affected by radionuclide releases) of waste disposal facilities and decommissioning sites.