1986

Chernobyl Disaster

The advent of nuclear power as an alternative to fossil fuels for the generation of electricity starting in the second half of the twentieth century has resulted in the construction of more than 450 nuclear power stations now in operation around the world, accounting for about ten percent of the world’s total electricity generation. While the safety record of this growing industry is generally outstanding, because the systems being used often involve high pressures, temperatures, and (by definition) radioactivity, accidents do occur.

The worst nuclear power accident to date occurred in April 1986 at the Chernobyl nuclear power plant near the town of Pripyat, in the Ukrainian Republic of what was then the Soviet Union. During a safety test, one of the station’s reactors overheated and caused an uncontrolled nuclear chain reaction, or criticality accident, that led to a catastrophic steam explosion and an intense open-air fire that released large amounts of radiation high into the atmosphere, as well as radioactive fallout directly onto the local environment. More than 50,000 people were evacuated from the regions around the plant, including the entire towns of Chernobyl and Pripyat. More than fifty people, including many employees and first responders, died either immediately or shortly after the accident, and as many as 4,000 additional cancer deaths are predicted to occur from people who had been living in the region near the facility. Shortly after the accident and evacuation, a 1,000-square-mile (2,600-square-kilometer) “exclusion zone” was set up around Chernobyl. The Zone, as it is called, remains a vast, unpopulated, semi-urban landscape to this day, and is a solemn reminder of the potentially devastating effects of a nuclear power plant accident.

In 1990, the International Atomic Energy Agency (IAEA) established the “International Nuclear Event Scale,” rating nuclear accidents from 0 (no safety concerns) to 7 (major accident with widespread health and environmental effects). Chernobyl was the only level-7 accident until 2011, when some of the Fukushima Daiichi nuclear power plant’s reactors outside Tokyo, Japan, overheated as a result of a large earthquake and tsunami. The worst nuclear accident in the US, the 1979 partial meltdown of a reactor at the Three Mile Island nuclear power plant in Pennsylvania, rates as a 5 on the IAEA scale.

A 2017 photo of the Chernobyl Victims Memorial, in front of the nuclear power station’s reactor #4 building, part of which is now a cement sarcophagus entombing the original reactor chamber.