Importance of thermal ecological studies in environment management around nuclear power plants

In thermal power plants, only about 30% of the heat energy generated is converted to electricity. Remaining heat is released to the environment either to atmosphere or to the nearest water body. During the operation of plants, it is essential to ensure that the release of heated effluent does not lead to any harmful consequences to eco system. Ministry of Environment and Forest (MoEF) has stipulated stringent regulation with respect to temperature of the heated effluent that can be released to the environment. All power plants under DAE are strictly following this stipulation. As a pro-active step, Department of Atomic Energy (DAE) carried out a comprehensive environmental impact assessment studies at Kalpakkam (coastal) site and at Kaiga (inland) site. The studies at Kalpakkam were coordinated by Water and Steam Chemistry Laboratory, Kalpakkam and the studies at Kaiga site was coordinated by Environmental Survey Laboratory, Kaiga. In addition to temperature mapping at the mixing zone, a detailed analysis of influence of heated effluent on water quality, primary productivity, benthic eco system, bio geochemical cycle, fish composition and diversity were carried out by different specialist groups under a coordinated BRNS project. The comprehensive thermal ecological studies clearly indicated that release of heated effluents does not lead to any significant impact on the overall ecosystem of the respective water body at Kalpakkam and Kaiga sites. Data generated in these studies are very useful in the designing suitable out fall system so that ecology of the aquatic body is not disturbed. This paper presents the highlights of the importance of such studies and salient features of the studies. (author)