" | | The other option evaluated is that of chemical competition. We have established a series of experiments showing that K (potassium) added to the K-deficient coral soil is very effective in preventing the uptake of 137Cs into food crops, including coconuts (BARC, 1988; Robison et al., 1988). — Through the addition of K, the !37Cs concentration can be reduced by more than 90%, so estimated doses at Bikini Island from al] exposure pathways, including the terrestrial food chain, would be below the current Federal guidelines. radiation In addition, the added K increases the quality, growth rate, and productivity of the vegetation. | The major advantage of the chemical-competition alternative is that it eliminates the tremendous environmental option. insult inherent in the excavation The mature coconut trees and all other vegetation can be left in place. In addition, all the surface soil with organic matter is left in place. A perceived disadvantage is that although the 137¢s can be reduced in food crops by adding K so that the total estimated doses are below 170 mrem/y, the '37cs and the 905r, 239+240py, and 241Am, are still present in the soi}. The !37cs and 90Sr will disappear due to radiological decay and environmental loss in about 90 y. very Jong periods The 239+240py and 24am will of course be present for of time. However, the estimated doses from these radionuclides are very low, and the radionuclides will become less available as they move deeper in the soil column. ACKNOWLEDGMENTS We appreciate very much John Rehder, the excellent support of James William Phillips, and Bobby Lynn Smith Johnson, in the field and laboratory phases of the project. Carol Stoker and Steve Kehl have been of great reduction, and evaluation of the data help in the organization, resulting from the analysis of samples collected at Bikini Atoll. Mark Mount has played a key role in the quality-control phases of our analytical effort. The processing of thousands of samples, the data retrieval and reduction was completed through the superb efforts of the following people: Jeff Brazelton, Nina Brown, Karen Davis, Mike Granillo, Liena Boone, Steve Hall, Richard Herbert, Henry Jones, Ben Kuhn, Joe Silveria, Stan Thompson, and all the people who worked on the 1978 NMIRS project. 72 (The latter group of people