Response to an accident in theory and in practice

Although numerical upper and lower levels of dose for countermeasures applicable in the early and intermediate phases after an accident had been identified at the time of the Chernobyl accident, there were no internationally agreed values for derived intervention levels. Emervency plans, including some criteria and procedures for intervention in the event of an accident affecting nuclear installations within national boundaries, had been developed generally as a part of licensing procedures. However, countries were ill-prepared to deal with the effects of transboundary radionuclide releases originating in other countries. At the Chernobyl site, a number of workers suffered whole-body doses which produced various forms of acute radiation syndrome. although no member of the public was exposed to such a high dose, it soon became apparent that the lower intervention level for evacuation adopted in the USSR (250 mSv whole-body dose) could be exceeded, and eventually even the upper intervention level of 750 mSv if the population remained in the immediate vicinity of the accident site. In some areas within the western part of the USSR, it was therefore necessary to implement the full range of possible countermeasures. In other European countries, the dose equivalents committed from the first year of exposure and intake ranged between a few μSv and about 1 mSv, being in the order of μSv or tens of μSv outside Europe in the Northern Hemisphere. In this article, we review the reactions of national authorities to the accident; and, in the second part, we consider informally the response of world news media to the accident, and its influence on public perception.