APPLICATION OF DECISION SUPPORT SYSTEM JRODOS FOR ASSESSMENTS OF ATMOSPHERIC DISPERSION AND DEPOSITION FROM FUKUSHIMA DAIICHI NUCLEAR POWER PLANT ACCIDENT

After the Chernobyl accident, the European Commission − under the auspices of its Research and Technological Development Framework Programme − has supported the development of the RODOS (Real-time On-line DecisiOn Support) system for off-site emergency management. The multiplatform version of RODOS was recently redesigned as a user-friendly system applicable for various computational platforms and easily customizable for different sites of nuclear power production. This new version was named JRODOS, as its software implementation base is Java language. In March 2011 JRODOS was customized for the site of the Fukushima Daiichi Nuclear Power Plant (NPP). JRODOS was applied to perform atmospheric dispersion and deposition calculations and to assess the doses to the public in the vicinity of the NPP. From the second half of March 2011 onward, results of the assessments were presented to the public and mass media on the website of the Karlsruhe Institute of Technology. The Numerical Weather Research and Forecasting model (WRF) has been implemented for the region around the NPP to produce threedimensional fields of the meteorological parameters that were further used by the JRODOS system. Prognostic and diagnostic assessments of the radiological situation in the vicinity of the site have been performed at least once per day with various source terms. Taking into account the high uncertainties in the source term estimation, the simulated results show a reasonable fit to the monitoring data obtained later. The study demonstrated the flexibility of JRODOS for the assessment of the consequences of nuclear accidents at different nuclear energy production sites.