The Chernobyl disaster was the most catastrophic accident to ever occur at a nuclear power plant. The accident caused the direct deaths of 31 people, but there were also deaths from radiation poisoning, a helicopter crash and 6,000 cases of thyroid cancer in and around the region of the disaster, it was confirmed in 2008. Some of these long-term effects, particularly the cancers, are being continually investigated today.
On the 26th April 1986 (approaching 30 years ago) the disaster began whilst a system test was being carried out at the fourth reactor of the nuclear plant, based in Pripyat, Ukraine. An unforeseen power surge occurred to which an emergency shutdown was attempted. One of the reactor vessels experienced a breach, which caused a number of steam explosions. The graphite moderator was exposed to air, which caused it to set alight. The ignition caused a release of highly radioactive fallout into the air and eventually affected the western Soviet Union and other parts of Europe, especially Pripyat itself.
The International Nuclear Safety Advisory Group (INSAG), formed specifically to identify causes of the disaster supported the original presumption that the Operators were to blame. Their investigation found there to be huge breaches of rules and regulations.
"During preparation and testing of the turbine generator under run-down conditions using the auxiliary load, personnel disconnected a series of technical protection systems and breached the most important operational safety provisions for conducting a technical exercise."
There was a large gap in the experience and knowledge of reactor physics and engineering, which is thought to have had detrimental effects on the decisions made and ignorance of the safety regulations. There was also a lack of communication between the operators and the safety officers, which was thought to have an influence on the events. The possibilities of the accident occurring were constantly pushed aside and ignored, because it was thought that it was such an unlikely risk that didn’t need to be addressed.
Noble gases (e.g. xenon and krypton) that were inside the reactor contaminated the air momentarily after the explosion occurred. With ionizing radiation entering the atmosphere, many citizens in the surrounding area and workers at Chernobyl contracted acute radiation syndrome (commonly known as radiation poisoning). This will begin to take effect within a 24 hour period after high exposure to radiation. The ionizing radiation causes damage to DNA within the body’s cells, causing symptoms such as nausea, vomiting and other common symptoms related to a lack of blood count. The radiation poisoning can also cause skin changes and various types of cancer.
After the disaster, the incident of congenital defects increased to 40% over a 6 year period since the disaster. This suggested that it was the main cause of infant deaths in the region.
The future of Chernobyl
The area surrounding 19 miles directly outside the power plant has now been named the ‘zone of alienation’, which has been described as a ghost town. The 300 people living there refused to leave when the area was evacuated and it’s highly overrun by plants and wildlife due to the lack of human activity.
On the 26th April we will remember those that lost their lives due to the devastating Chernobyl disaster.