Assessment of the fresh water residence time will be made from the data. The well network, once established, will be available for resampling on subsequent trips we plan to the atoll to thoroughly assess the dynamics of radionuclide cycling in the ground water reservoir and to maintain a surveillance on the water quality. The program operation will be fashioned after our Enewetak ground water study and comparison of the data from both atolls should be especially valuable for predicting the mechanism and rates of constituents in ground water at Pacific atolls. The U. of Hawaii (Dr. R. Buddemeier) will have the analytical responsi- bility for major element analysis and LLL (V. E. Noshkin) will have the responsibility for radionuclide assessment. We will determine the concentrations of Csl137, Sr90, and plutonium in all samples by radio chemical techniques. Gamma emitters present in a ferric hydroxide precipitate will be identified and the levels assessed from the spectrometry data. Tritium will be measured on selected samples. Plant/Soil Sampling Program Purpose: The main thrust of the program will be to determine radionuclide concentrations in food species, to correlate these with soil concentrations at various depths, to determine nuclide availability to plants in the coral soils, and to relate the food-species radioactivity to other indigenous nonfood species which may have indicator species potential. The unique information that this survey will provide is: 1. Soil-to-plant and soil-to-fruit concentration factors for detectable radionuclides. 2. The relationship between food species and nonfood species at the same location. 3. The relationship between total soil radioactivity and the radioactivity which is aveilable to the plant in the soil: solution at the time of sampling. 4. The relationship of vegetation, soil, soil water, litter, and humus in the overall cvcling of radionuclides in mature food crops. 5. The re’ationship of lens water radioactivity to that in soil water and plants growing above the lens zone in order to determine the rate of loss (time dependent information) from the coral atoll environment. 6. 7. Intra-island variability in vegetation radionuclide concentrations. Supply the data base for assessment. of terrestrial foad chain transfer of radioactivity from the soil to man for long-term dose - evaluation upon rehabiliation of the atoll. 900251 ; . DOE ARCHIVES