Studies on transfer coefficient from grass to milk for 137Cs and 40K at Kakrapar Gujarat site, India

Transfer coefficient from grass to milk (Fm) for 137Cs and 40K was computed based on the activity measurement data in the respective matrix at Kakrapar Gujarat site, India, during 2013 - 2019. The annual geometric mean value of 137Cs activity in grass and milk samples varied from 0.13 to 0.48 Bq/kg dry wt. and 0.03 to 0.14 Bq/l, respectively. Activity observed during the year 2013 - 2019 is comparable with preoperational baseline activity level, which indicated its fallout origin. The site-specific Fm has varied between 1.0E-02 to 3.71E-02 d/l with a GM of 2.22E-02 d/l (137Cs) and between 6.69E-03 to 1.54E-02 d/l with a GM of 9.63E-03 d/l (40K), respectively. The annual effective dose due to the ingestion of 137Cs and 40K through milk consumption was found to be 0.036 μSv/y and 16.94 μSv/y, respectively. The result is an useful input for the estimation of radiation dose to human beings in accidental conditions.