Environmental 137Cs contamination was suspected from accidents at spent fuel storage pits of a research reactor site in the Ta-han River valley in Taiwan. In order to further characterize this contamination, soil samples were collected and measured by a gamma-spectroscopy system in 1999. It was found that 137Cs contamination is distributed up to 4km from the reactor in an area covered mostly by rice and plant fields. 137Cs concentration in the topsoil ranged up to about 1000Bqkg-1, as compared with soil beyond the contaminated area, which does not exceed 15Bqkg-1. Spatial distribution of 137Cs was characterized by strong non-uniformity, which complicated our understanding of the distribution pathway of the radionuclides. The highest concentrations of 137Cs, up to more than 1000Bqkg-1, were found within a few rice fields. The relative location of these rice fields and the water supplies from local streams suggested that the 137Cs was distributed along water pathways in the valley.
ASJC Scopus subject areas
- Environmental Science(all)