The initial impact
As a result of two explosions radioactive gasses and material were flung far into the atmosphere. The majority of the material settled in the surrounding area, but the lighter matter was carried on the wind and into nearby countries, including Belarus, Russia, Scandinavia and parts of Europe and would have a lasting impact. Despite the enormity of the accident no report was made about it until 2 days later when the Swedes detected a dramatic increase in wind-borne radiation.
The initial casualties included two workers that had been killed instantly in the blast and more than thirty firefighters who had been sent in to fight the blaze. The 1000 emergency workers sent to help with clean up and the on-site personnel from that first day suffered high exposure to radiation which would later lead to serious health effects. In addition some 100,000 people had to be evacuated from their homes in an attempt to avoid the radiation.
The cause of the incident
Over the weeks following the official report it was discovered the serious errors had been made on the part of workers in the plant. The first discovery was that the indirect cause of the explosions had been an unauthorized test. The test was an attempt to figure out what would happen if the power to the plant had failed.
During that unauthorized test many mistakes were made that eventually lead to the explosions. The first and most important mistake was turning off the emergency coolant system. During the test the core of the reactor was allowed to reach 5000 degrees Celsius, the temperature rising from an unexpected power surge. This extremely high temperature produced molten metal. The metal then reacted with the cooling water to produce hydrogen gas and steam, which was the direct cause of the explosion.
The after-effects of the Chernobyl disaster
The effects of the accident were far-reaching. The long term effects of the plant explosion were, and still are, much more disastrous than the immediate losses. The result of exposure to the radiation could be significant numbers of people dieing of cancer. The fallout levels from the accident were eventually much higher than that of the atomic bomb dropped on Hiroshima.
Immediate areas surrounding the plant were the most affected. All nearby plants and animals were contaminated and experts predict that it may be hundreds of years before the land could be arable again. Those who live in the contaminated area face serious long term health effects. Other areas were also affected by the radioactive material that was carried on the wind. The radiation was carried as far as Italy and some Italian vegetables were even found to be contaminated. Also affected were the animals in Europe. For a time fresh meat the originated in Eastern Europe was banned by the European Community (the EC)
Chernobyl today
The nuclear plant unit 4, where the explosion occurred, is now covered over with a concrete structure designed to allow the rest of the plant to continue operating. However that structure is not efficient and because roughly 200 tons of radioactive material remains a new Safe Containment structure is currently being built. Despite the horror of the incident some lessons have been learned. Among them are the new safety regulations currently in place for new reactors.
Sources:
World Nuclear Association ‘Chernobyl Accident’ http://www.world-nuclear.org/info/chernobyl/inf07.html
http://www.chernobyllegacy.com/
Medvedev, Zhores A. The Legacy of Chernobyl. W. W. Norton & Company (February 1992)
