Environmental radiation measurements and comprehensive impact assessment around a nuclear power plant site in Kaiga, India

This paper presents the results of environmental monitoring of Kaiga site and impact assessment due to the operation of two PHWR type reactors. Measurements of radionuclides were carried out in atmospheric, terrestrial and aquatic environmental compartments using state-of art techniques and radiological impact due to external exposure, ingestion, inhalation and skin absorption pathways to individual member of public evaluated. A hypothetical case of OBT intake through contamination of crops due to tritium is also considered. The paper also presents the results of estimation of Site Specific Transfer Factors required for the impact assessment modeling. The parameters required for dose evaluation and respective uncertainties for each parameter were attributed. The dose distribution was estimated using parameter uncertainty analysis from all the pathways and for all the major radionuclides. Dose distribution was found to be lognormal and ranges from 0.2 - 5.8 μSv.a^-1 (at 95% Confidence) with a mean value of 1.1 μSv.a^-1 in the year 2006. Since the upper limit of 95% confidence level is below the regulatory limit, violation of the limit is highly unlikely. Statistical analysis of ¹³⁷Cs concentration in soil and sediment samples indicate that there is no build up of ¹³⁷Cs in the environment as compared to pre-operational value (p<0.001). (author)