Non-destructive determination of 235U, 238U, 232Th and 40K concentrations in various consumed nuts and their implication on radiation dose levels to the human body

The naturally occurring radionuclides of U-238,U-235,U-234, Th-232 and K-40 and their daughter products are a potential source of radiation found in food. We have determined these five radiation sources in five popular consumed nuts. We used the following neutron activation analysis reactions of U-238(n,gamma) U-239, Th-232(n,gamma)Th-233 and K-41(n,gamma)K-42 to determine U-238 and Th-232 and K-40, respectively. Using known activity ratios of uranium stable isotopes we determined the activity of U-234,U-235, while K-40 was found by the determined concentrations of K-41 in the nuts. While the radiation doses are small we have established a reliable methodology to determine these radionuclides in typical edible nuts.