Already the nuclear industry, in its relatively brief history, has had serious accidents which have led to the release of large quantities of radioactive materials into the environment.
These are a British reactor fire at Windscale, where the graphite moderator overheated, and the disaster [previously explained] at Kyshtym in the Urals.
The British accident sent a plume of radioactive contaminants across Britian to Denmark and over the European continent. Part of it passed across the Irish Sea into Ireland... the greatest contamination occured close to the reactor itself.. thousands of gallons of milk had to be poured out because it contained high levels of iodine-131.
Every attempt was made to cover up the implications of the Windscale Fire... no advice was given to the public in the vicinity or indeed in the path of the plume to take simple precautions - such as staying indoors when the radiation in the air had reached its peak.
By the time of Chernobyl in 1986, all European countries had networks of radiation-monitoring stations, particularly in sensitive areas such as those close to nuclear power plants.
It was therefore no coincidence that the first indication in the West of a nuclear disaster somewhere in the Soviet Union, and very quickly pinned down to the Ukraine, was from abnormally high level readings of radioactivity in the air at Forsmark nuclear power station on the Eastern side of Sweden.
Indeed, when workers arrived at the Swedish station on the morning of the 28th April 1986, they were stopped from entering the plant because of contamination on their faces, hands and clothing. Activity was also found on cars in the car park, on the ground, and in puddles of water. Workers were therefore sent away and both local and central authorities were notified to put them in a state of readiness for carrying out routine emergency action and establishing countermeasures.
Within the first day, the emergency task force had concluded that evacuation of any of the Swedish population, sheltering them or advising them to take iodine tablets to counter the fallout of radioactive iodine would not be justified. Similar conclusions were reached throughout Western Europe, although more careful analysis of the situation in hot-spot areas revealed later that a more judicious approach might well have been followed.
Radiation levels in the Ukraine increased over three years before returning to May 1986 levels. As we learned from the Chernoble accident, we can expect, then measured high radioactivity in livestock to increase six months after the initial fall-out. If the initial weather conditions were rain when the plume reached other cities and nations, the levels of radioactive caesium in livestock will continue to increase in those areas. Obviously, not all localities are measured for fall-out, and some areas will be entirely missed (especially in the countryside) and people who live there left in ignorance. What we have learned is we should be on our guard if it rains heavily at a time when the radioactive cloud is somewhere in the vicinity. If there is contaminated air in the vicinity, we should not go outside, nor drink rainwater, and not go for a swim. Animals must be sheltered and kept inside for many weeks. This reduces the exposure to short-lived radio-isotopes like iodine-131. Contamination of food will be a problem where fall-out has contaminated the supply of wheat and feed. Wild vegetation tends to be more efficient at concentrating radioactive material than well-fertilized domestic crops. Game animals that live on these plants are likely to have higher levels of radioactivity compared with domestic ones. Some buildings are more effective in shielding us from radiation than are others. The best protection is found in an air-tight building, concrete blocks or apartments. The traditional wooden structures are less protective. If you remain in the area, you might move to a prefabricated air tight home. Filters in an air cleaning system will have to be replaced following a radioactive event, and care must be taken when changing and disposing of the contaminated filters. If iodine tablets were not issued, uptake of radio iodine may be lessed by consuming kelp. The main task after a major radiation release should not be to hose down vehicles, roads, buildings, because that only disperses the particles into the soil; the main task is to confine the contamination and dispose of it at a safe site. When the source of decontamination is closed and secured, the task of collecting fall-out begins. The Soviets sprayed a light, sticky plastic film over the surface of the ground, which was later gathered and disposed. The first few centimeters of topsoil have to be taken to a secure landfill site. Buildings can be coated with special paint, and roads may be tarred to bind radioactive fallout for collection and disposal.