NEW TRENDS IN DISPERSION STUDIES FOR SITE SELECTION OF NUCLEAR POWER PLANTS

The work deals with the manifestation of the role of dispersion analysis in site selection and evaluation of nuclear power plant (NPP) with emphasis on new applied trends and approaches used in defining the dispersion parameters at concerned site and expected concentrations. According to the regulations of International Atomic Energy Agency, the site proposed for NPP installation should have certain criteria. The estimation of concentration of radioactivity due to effluent releases in air and water during normal operation/accident conditions from a nuclear power plant is an important component of the regulatory safety assessment. The article discusses models used in dispersion analysis. The Gaussian-plume Model (GPM) used from the 1960 is applicable to ideal conditions of uniformity and steady state under which the data don t change with distance and time. In the last decade models which are functions in distance and time have been developed and used in dispersion analysis with more sophistication. These models take into account the effect of the following phenomena such as complex terrain, coastal conditions, boundary layer turbulence, pollutants accumulate in calm conditions and building downwash.