Analysis of operational gamma radiation monitoring in relation to baseline data in and around Kudankulam nuclear power project site, Tamil Nadu

Continuous monitoring of natural background radiation has grown significantly important in recent years. It not only monitors the environmental radiation levels but also provides the public assurance with regard to the safety of nuclear power plants. This paper discusses the preoperational (2003–2014) and operational (2015–2024) gamma radiation levels in and around the environs of the Kudankulam Nuclear Power Project (KKNPP) site, using thermo luminescent dosimeters (TLDs). Twenty-seven locations were selected for the TLD survey, all of them being situated in the various sectors, up to a distance of about 30 km from the site center. In general, there is a 20% variation across every location’s annual dose rate. The operational annual average gamma radiation level is found to be 1.23 ± 0.32 mGy/a which is less than the preoperational level of 1.36 ± 0.46 mGy/a. The reason for this anomaly is that a considerable amount of monazite-bearing sand has been replaced with building materials such as concrete, which have lower concentration of radioactivity.