Emergency measures taken after the accident

After the Chernobyl accident, the initial emergency measures taken at the nuclear station were fire-fighting and to stabilize the reactor. The fire in the plant was put out at 5 a.m. on 26 April 1986 after burning for more than 4 hours. The fire at the reactor core which consisted of a considerable amount of graphite had to be put out quickly so as to minimize the radioactive release. Emergency personnel employed aircraft to drop carbonized boron, dolomite, clay and lead to cover the damaged reactor. Pressurized liquid nitrogen was injected into the reactor base to remove heat from the core. A heat exchange passage was built and the base of the plant was reinforced to sustain the high temperature of the reactor core. To further prevent the leakage of radioactive materials into the atmosphere, a concrete confinement known as 'sarcophagus' was built to cover the remains of the damaged reactor core after half a year later, in November of 1986.

A number of offsite emergency measures were also taken. This included

1. protective measures for the public such as sheltering, evacuation and taking of radioiodine;
2. relocation of several tens of thousands of livestocks from the contaminated area; measures to prevent or reduce contamination of drinking water and underground water; food interdiction, in particular milk;
3. border control of people and vehicles within a radius of 30 kilometres(km) from the accident site; and
4. decontamination of houses, especially the public buildings including schools and kindergartens, within an area of 7,000 sq. km. Those houses that could not be decontaminated were demolished and burnt.