Thoron levels in the dwellings of high background radiation area located around Kudankulam nuclear power plant

Abstract Thoron concentration levels have been measured in the high background radiation area located around Kudankulam nuclear power plant i.e. in the Agastheeswaram, thovalai taluks (sub-district) of the Kanyakumari district using solid-state nuclear track detectors. Measurements have been carried out on quarterly cycles making four measurements at each location throughout a year. Totally 100 dwellings have been selected for the study. Thoron concentration has been found to vary between 4.6 and 143.5 Bq m −3 with the geometric mean value being 25.1 Bq m −3 . Results have been analyzed for different categories of dwellings with respect to their construction type.