To Open The Sky

Accidents Involving Nuclear Energy

Incidents and Accidents

The table below presents a chronological list of over 940 color-coded symbols, each of which links to the description of a single Incident. The central code in each symbol identifies the country responsible, following the two-letter ISO country codes. The number at upper left is intended to give the INES level of severity for each incident. The number at lower right indicates the number of people affected, on a sort of logarithmic scale: "1" means 10 or fewer people; "2" means 11 to 100, and so on. Finally, you'll see the symbol text in large and small sizes. These designate major and minor incidents, respectively. If there are deaths or serious injuries, I rate an incident major. Release of lots of radiation to the outside might also qualify as major, even with no immediate casualties. An example is the drying up of Lake Karachai in Siberia, which allowed years of rad-waste dumping to drift over the countryside as dust.

The great majority of these events are minor in effect: Contamination of a single building, with no personnel exposed, or a reactor scram with no damage. But the thing to remember is that a pattern of minor problems often leads to a major problem, and certainly suggests that some changes ought to be made. That is why I've sought to include as many as I can. The record of nuclear power is replete with such problems, and while things are getting better, there is no justification for complacency.

Two caveats: INES (International Nuclear Event Scale) levels really apply only to reactor incidents, and are not always published. Neither is the number of people affected always available. What it comes down to is, in most cases I've had to guess at these numbers.

The seven INES levels are color-coded, and I reproduce those colors here. But the eleven color codes in the chronological chart have a different purpose: They represent the type of incident. For example, red means a reactor accident; olive drab stands for military weapons facility incidents. There's really no good way to convey the meaning of these symbols purely in words. For a full explanation, use the keys below.