Ocean circulation modelling for aquatic dispersion of liquid radioactive effluents from nuclear power plants

Full text of publication follows: Recently, three-dimensional models have been used for aquatic dispersion of radiological material in relation to nuclear power plant siting based on the Notice No. 2003-12 'Guideline for investigating and assessing hydrological and aquatic characteristics of nuclear facility site' of the Ministry of Science and Technology (MOST) in Korea. Several nuclear power plants have been under construction or planed, which are Shin-Kori Unit 1 and 2, Shin- Wolsong Unit 1 and 2, and Shin-Ulchin Unit 1 and 2. For assessing the aquatic dispersion of radionuclides released from the above nuclear power plants, it is necessary to know the coastal currents around sites which are affected by circulation of East Sea. Model Description In this study, a three dimensional hydrodynamic model for the circulation of the East Sea has been developed as the first phase, which is based on the RIAMOM (Research Institute of Applied Mechanics' Ocean Model, Kyushu University, Japan). The model uses the primitive equation with hydrostatic approximation, and uses Arakawa-B grid system horizontally and Z-coordinate vertically. Model domain is 126.5 deg. to 142.5 deg. of east longitude and 33 deg. and 52 deg. of the north latitude. The space of the horizontal grid was 1/12 deg. to longitude and latitude direction and vertical level was divided to 46. This model uses Generalized Arakawa Scheme, Slant Advection, and Mode-Splitting Method. The input data were from JODC (Japan Oceanographic Data Center), KNFRDI (Korea National Fisheries Research and Development Institute), and ECMWF (European Center for Medium-Range Weather Forecasts). Results and Further Study The modeling results were simulated well northwest eddy near the Ulleung basin which could influenced the ocean dispersion of radionuclide in the East Sea. The local current model and aquatic dispersion model of the coastal region will be developed as the second phase. The oceanic dispersion experiments will be also carried out by using ARGO Drifter around a nuclear power plant site. (authors)