137Cs in Urine of Tourists Who Visited Kiev Late in April, 1986. - Estimation of the Intake of 137CS and 239Pu Due to the Nuclear Reactor Accident

Gamma-ray spectrometry analysis was made of urine samples from 43 tourists who had visited Kiev late in April, 1986. Seven of 43 samples contained significant amounts of 137Cs ranging in concentration from 0.14 to 0.40 pCi/ml along with other fission products. The initial intake of 137Cs was estimated to be 50 to 230 nCi, which would result in a rise of the level of 137Cs retention up to two orders of magnitude. Tourists' baggage was also submitted to gamma-ray spectrometry analysis at NIRS*. The results suggested the presence of 239Np in air in Kiev and the possibility of the inhalation of its daughter nuclides by tourists. The intake of 239Pu was estimated to be 220 to 1400 pCi from each estimated value of the 239Pu/239Np radioactivity ratio in the fuel, the 239Np/137Cs ratio in air and the 137Cs body burden.