Читать книгу Industrial and Medical Nuclear Accidents - Jean-Claude Amiard - Страница 22

We have seen that criticality accidents (resulting from an unintended chain reaction) were frequent in the military arena between 1945 and 1970 [AMI 19]. This type of accident has also occurred during the manufacture of nuclear fuel for nuclear power reactors, in the latter themselves, and in industrial and medical applications of nuclear technology (linear accelerators, radiotherapy). Accidents can occur in aqueous fissile media, in solid or dry metal media, and in mixed solid/liquid media. On the contrary, no cases have been reported for “powder” media.

Most accidents occurred in the United States (Hanford, Idaho Falls, Los Alamos, Oak Ridge and Wood River Junction) and in the former USSR (Obninsk, Electrostal, Mayak, Tomsk and Novosibirsk) [MCL 00] (Figure 1.1).

Since 1945, 60 criticality accidents, only six of which occurred after 1978, have occurred worldwide, mainly in research reactors and in laboratories. This means that until the early 1980s, there was more than one accident per year. The last three accidents occurred in Tokai-Mura, Japan (two in 1997 and one in 1999).

In a significant number of cases, these accidents resulted in immediate deaths or severe radiation exposure leading to premature death. Criticality accidents resulted in 17 deaths [GAM 07], 19 deaths [IRS 09a] or 20 deaths [MCL 00] depending on the sources. The procedure to be followed in the event of a criticality accident has been detailed by Miele and Lebaron-Jacobs [MIE 05].

Figure 1.1. Chronology of the main criticality accidents (adapted from [MCL 00]). For a color version of the figure, see www.iste.co.uk/amiard/industrial.zip