The paper provides details on the re-engineering of the European decision support system for nuclear emergencies RODOS. Being a Java based product, the new RODOS version named JRodos introduces a cross-platform solution capable to run on most operation systems, including Windows and the main UNIX derivates. The re-engineered system preserves computational models from RODOS v6.0, adding a powerful GIS support and applying modern database technologies with flexible configuration possibilities. JRodos import functionality includes the support of EURODEP measurement files and GRIB 1 meteo data. The system operates successfully on Windows (NT based versions from Windows 2000 to Windows 7) and UNIX machines (OpenSuSe, Ubuntu, Solaris), both ×86 and ×64. Any RODOS further development will be realized in the JRodos version aiming to have this as the main operational version for the next 10 years.

To simulate the radionuclide transport in stratified water bodies the THREETOX three-dimensional time-dependent flow and transport code has been developed. The prognostic variables are the three components of the velocity field, temperature, salinity, surface elevation, suspended sediment concentration, the radionuclide concentration in the solute, suspended sediments and bottom deposition. The model was applied to the Kiev reservoir and Dnieper-Bug estuary to predict the radionuclide fields of Chernobyl origin. Results revealed that THREETOX appears to simulate well the radionuclide migration in the stratified and homogeneous water bodies with complicated geometry and time-dependent flow.

One of the major objectives of the 6th Framework EC RTD EURANOS (European Approach to Nuclear and Radiological Emergency Management and Rehabilitation Strategies) project was to improve the RODOS (Real-time on-line decision support) system in its operational applicability. In the first phase of the project two possibilities for the main system development has been discussed: either to carry out refinements in the current version of RODOS or to consider a complete software re-engineering. The RODOS Users Group (RUG) finally concluded that the latter option was one to be realised. As a result a JAVA based version named JRODOS has been developed introducing a cross-platform solution capable to run on most operation systems, including Windows, Macintosh and the main UNIX derivates. The re-engineered system preserves computational models from RODOS, adding a powerful GIS support and applying modern database technologies with flexible configuration possibilities. Furthermore, these new GIS functionalities allowed implementing advanced simulation models for simulating countermeasures in inhabited areas (ERMIN - European Model for Inhabited Areas) and food production systems (AGRICP – Agricultural Countermeasure Program). Both simulation models have been part of the EURANOS project and represent state of the art modelling capabilities in their respective area.