Keywords: operational intervention levels, radiological emergency, dose prediction, uncertainty, variability, nuclear reactors, nuclear accidents, nuclear emergency, emergency preparedness, emergency management, dose distribution, temporary relocation, non-urban environment, core melt accident, Monte Carlo simulation
Validation of the concept of default operational intervention levels in nuclear reactor accidents by Monte Carlo calculations
The concept of Operational Intervention Levels (OILs) is introduced by the IAEA to predict a dose to an individual in the case of a nuclear reactor accident. Deterministic calculations on the averted dose lead to a single number only. Large uncertainties are associated with such predictions, because many parameters have an inherent uncertainty and variability. For these reasons, Monte Carlo (MC) calculations were made in this paper to demonstrate the variation of the results and the compliance with the preset numbers. Results of calculations taking into account several conditions will be presented to show the dose distribution of the prediction as well as key issues. Although this was only a limited examination of the uncertainties involved, it appears that the default OIL-4 is a reasonable basis for making decisions concerning temporary relocation in a non-urban environment early after a core melt accident.