Assessment of off-site early countermeasures in the event of a LOCA in a research reactor

Off-site early emergency management actions due to a potential release from the Greek Research Reactor-1 are assessed with the aid of a modern decision support tool. To this end, a hypothetical loss-of-coolant accident has been assumed under two distinct ventilation schemes of the reactor building. Five, site-typical, meteorological scenarios have been applied based on observed conditions that demonstrate the effects the released radioactive plume has on the surrounding urban area. The JRODOS (Java-based Real-time On-line DecisiOn Support) system has been used to calculate gamma radiation doses, estimate the affected areas and assess early countermeasures in accordance with national legislation. The results indicate that the suggested countermeasures may need to be applied only to a very limited area in a few of the considered weather scenarios.