Lessons learned from Chernobyl and other emergencies: establishing international requirements and guidance

In the past 25 years, nuclear and radiological emergencies have occurred that cover much of the range of causes and types that had been anticipated by experts. Experience from response to these emergencies has clearly demonstrated the importance of an efficient response system that includes, among other components, emergency plans, procedures, and internally consistent operational criteria. An analysis of lessons identified from recent responses has shown that a lack of crucial components in the emergency response system could result in major radiological and nonradiological consequences at the national level. A rigorous examination of the response to past emergencies has shown that there is a need for additional consistent international guidance on taking protective and other response actions and for placing the guidance in a context that is both comprehensive for the decision makers and can be explained to the public. This paper briefly describes the lessons learned from past radiation emergencies and how these lessons are used by the International Atomic Energy Agency in developing the international guidance in the area of emergency preparedness and response. In particular, the paper discusses the proposed extended framework of emergency response criteria. The framework is composed of two fundamental parts: (1) generic reference levels and (2) a plain language explanation for each generic reference level to assist the decisions makers and the public in making informed decisions on the actions they should take when this level is reached. The system of generic reference levels covers the full range of potential and actual exposures, from those levels that can result in severe deterministic health effects down to those that allow for a return to normality.