ESTE-DECISION SUPPORT SYSTEM FOR NUCLEAR AND RADIOLOGICAL ACCIDENTS.

Described are functions, models and approaches of software tool Emergency Source Term code (ESTE), which is decision support system for crisis staff in case of nuclear or radiological accidents. The first task of ESTE in emergency situation at nuclear facility is to evaluate state of reactor core or state of fuel in spent fuel pool, on the base of state of barriers which should prevent the release of radionuclides to the environment. The main task is to prepare outputs, which can be utilised for recommendation of protective measures. Measures include sheltering, iodine prophylaxis and evacuation inside the emergency planning zone and potentially beyond the zone. The paper summarizes approaches of ESTE, including dispersion models and reverse modeling approach applied for estimation of real release to the atmosphere of the environment. Compared are intervention levels implemented in ESTE for urgent measures in Slovakia, Czech Republic, Bulgaria, Iran and Austria.