NUCLEAR RISK AND VULNERABILITY

摘要

The risks for radioactive contamination and significant radiological consequences connected with sources in this or adjacent areas, in some cases predominantly affect the conditions at local and regional levels, yet in others appear to be far reaching, and of considerable concern for the whole Arctic region. Thus, it is of particular interest to expound on issues such as: Which sources appear to be the most dangerous ones for those living close to and far from these sites? Which regions are on the highest risk from a hypothetical accidental release in the Euro-Arctic? The purpose of this paper is to overview existing methodologies for complex nuclear risk and regional vulnerability assessments and their tests on estimation of a possible radiation risk to the population in the Northern countries in case of a severe accident at an NPP. For assessment of risk/vulnerability many different factors and indicators should be considered, including the probabilities: (i) probability of an accident of a certain severity at the radiation risk sites; (ii) probability of air transport pathways towards the area of interest from a risk object; (iii) probability of deposition/precipitation over this area during the transport of the plume along the trajectory; and the social-geophysical factors: (i) proximity to the radiation risk sites; (ii) population density in this area; (iii) presence of critical groups of population; (iv) ecological vulnerability of the area; (v) risk perception, preparedness of safety measures, systems for emergency preparedness; (vi) economical and technical means, counteracting consequences of a possible accident, etc. For estimation of vulnerability/risk for different regions, a risk function could be defined as a complex index of probabilities of risk for different factors and indicators. There are several approaches to define such a function. The most common method is used for estimation of possible dose for population and proceeds from the physical laws of radioactive matter transport from a nuclear reactor to Man. However, such an approach is inconvenient for an analysis of factors of different nature like, for example, geophysical processes of radionuclide transport and social-economical factors. So, alongside with the direct method, some authors suggest simpler and more universal approaches, based on a combination of different factors and probabilities of separate processes with appropriate weights. An optimal strategy for complex nuclear risk and regional vulnerability assessments in the Arctic and Sub-Arctic, based on a combination of different specific methods is suggested and discussed