Minimal radioactive discharges from Indian nuclear plants: study

Researchers at the Bhabha Atomic Research Centre in Mumbai have found that radioactive discharges from Indian nuclear power plants have minimal environmental impact, reinforcing India's commitment to its nuclear power program.

Based on an analysis of radiological data of 20 years (2000-2020) from six nuclear power plants based in India, researchers at the Bhabha Atomic Research Centre (BARC), Mumbai have found that the radioactive discharges from the nuclear plants and the resultant potential environmental impact have been “minimal”. “The findings hold potential significance for reinforcing India’s commitment to advancing its nuclear power programme,” the authors write. “The minimal public doses underscore the safe operation of Indian nuclear power plants. The study’s findings have the potential to dispel unfounded beliefs, serving as a catalyst to reinforce India’s commitment to advancing its nuclear power programme, thus encouraging policymakers and the public to reconsider their perspectives.”

The period of study for the Kudankulam Nuclear Power Station is from 2013 to 2020. The other six power plants studied are: Tarapur Atomic Power Station, Madras Atomic Power Station, Kaiga Generating Station, Rajasthan Atomic Power Station, Narora Atomic Power Station, and Kakrapar Atomic Power Station. The results were published recently in the journal Science of the Total Environment.

While samples were collected and measured for a maximum radius of 30 km of each nuclear plant, the study found that the concentrations of fission products beyond 5 km radius was below the minimum detectable activity of the instruments used, implying that the monitored values were “insignificant”. The study has therefore focussed only on the concentrations of fission products and neutron-activated nuclides values within 5 km of each nuclear plant.

The gaseous waste that is released to the atmosphere through stacks consists of fission product noble gases, Argon 41, radioiodine, particulate radionuclides —cobalt-60, strontium-90, caesium-137 — and tritium. The liquid discharge consists of fission product radionuclides — radioiodine, tritium, strontium -90, caesium-137 — and activation products like cobalt-60. The radioactive discharges are carried out through dilution and dispersion and by “adhering to strict radiological and environmental regulatory regimes”.

As per the study, average gross alpha activity in air particulates at all the seven nuclear plants was less than 0.1 megabecquerel (mBq) per cubic metre. “Though these gross values in air particulates appeared to be nearly the same across all the nuclear power plants, the Narora atomic power station (NAPS) exhibited higher maximum values than the other nuclear plants. This was attributed to the higher atmospheric dust load at NAPS compared to the other sites,” the authors write.

In the case of specific marker, the average radionuclides (iodine-131, caesium-137, and strontium-90) in air particulates across all the seven sites and the average iodine-131 activity concentration was below 1 mBq per cubic metre, while in the case of caesium-137 and strontium-90, the average concentrations were three orders lower and below 10 microbecquerel per cubic metre, they write.

In the case of rivers and lakes, the concentration of caesium-137 and strontium-90 were below 5 mBq per litre, while the concentration was less than 50 megabecquerel per litre in sea water near the nuclear plants.