BASELINE EVALUATION STUDY OF NATURALLY OCCURRING RADIONUCLIDES IN SOIL SAMPLES FROM VICINITY OF INDIA'S FIRST FAST REACTOR FUEL CYCLE FACILITY (FRFCF), DAE COMPLEX, KALPAKKAM, INDIA

The activity concentration of 238U, 232Th and 40K were measured in the soil samples collected from Fast Reactor Fuel Cycle Facility (FRFCF) site, using high-resolution gamma-ray spectrometry. This study is aimed to establish the baseline data of naturally occurring radionuclides within the site. The average activity concentrations were found to be 416.5, 61.7 and 622.3 Bq kg-1 for 40K, 238U and 232Th, respectively. The activity concentrations and its radiological indices were evaluated and were compared with the international values reported by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The ratio of 40K/232Th and 40K /238U were calculated, which indicates the presence of 5.79 and 2.69 times more K-bearing minerals as compared with Th and U-bearing minerals in the soil samples, respectively. The study provides baseline information on concentration of radionuclides and background radiological assessment of the FRFCF site.