The first part of this review discusses the importance of risk. Man seems to have a longing for risks, like a part of the human nature. If risks are missing, they have to be invented, as needed parts in the emotional attraction of sports, amusement parks, traveling, etc.; this is the emotional part of risk. There is also a rational part of risk, in selecting such objects in ordinary life big industry, with a technology poorly understood by the general public, is a favored target. In that category no better choice can be made than the nuclear industry in general, and the nuclear waste in particular. To the public, through laymen like journalists and politicians, the risk from nuclear waste seems only to be treated emotionally, while to the scientists and technicians it is an object of exact calculation: probability of accident times consequence. If there is any relation between the emotional and the rational risk perceptions (for example, it is believed that increased knowledge will decrease emotions), it will be a desirable goal for society, and the nuclear industry in particular, to improve the understanding by the laymen of the rational risks from nuclear energy. This review surveys various paths to a more common comprehension – perhaps a consensus – of the nuclear waste risks.
The second part discusses radioactivity as a risk factor and concludes that it (becquerel) has no relation in itself to risk, but must be connected to exposure, either external or internal, leading to a dose risk , i.e, a health detriment, which is commonly expressed in terms of cancer induction rate. Dose-effect relations are discussed in light of recent scientific debate.
The third part of this report describes a number of hazard indexes for nuclear waste found in the literature and distinguishes between absolute and relative risk scales. The relative risk is obtained by dividing the risk value associated with the source (e.g. a waste repository) by the risk (derived according to the same principle) of some known risk source (e.g. a uranium ore deposit in nature). The absolute risks as well as the relative risks have changed over time due to changes in radiological and metabolical data and by changes in the mode of calculation. Some of the effects of such changes are summarized in two Tables and an Appendix, and in a number of diagrams showing different absolute and relative risks vary with radiation protection data, reference choice, waste source, and time.
To judge from the literature, the risk discussion is huge, even when it is limited to nuclear waste. It would be very difficult to make a comprehensive review (or, rather, brew) where all viewpoints are digested, and from that extract the essentials. Therefore, we have chosen to select some publications, out of the over 100 at the end of this report, which we summarize rather comprehensively; in some cases we also include our remarks.