In the early hours of 26th April 1986, the biggest nuclear disaster ever hit Soviet Russia in what is now Ukraine. Initially, Russia attempted to cover up the disaster yet when other countries started to detect heightened levels of radiation, Russia was forced to admit that there had been an accident at a nuclear facility in Chernobyl.
The engineers at the nuclear power plant had begun an experiment to see if the cooling pump system would work on low power should the external power source fail. Control rods are used in nuclear reactors. They are made from boron, which is effective in absorbing neutrons which in turn, slows down nuclear fission in the reactor. A number of these rods were remotely lowered into the reactor to reduce the energy output of the reactor to 20% of its capacity. However too many of these rods were dropped and the nuclear fission reaction nearly stopped completely, running at only 7% of its total capacity. Worried that the output would cease completely, engineers began to raise the rods. Just over 20 minutes later, the energy output had only risen to 12%. Then, there was a sudden power surge. This caused the cooling water to turn to steam. At this time, only 6 boron rods remained in the reactor, despite the safe minimum number being 30. An emergency shut down was caused, and the rods began to re-enter the reactor. However, this displaced the coolant and focused the reaction in the base of the reactor. The pressure this caused was immense, and soon, there was a large explosion blowing the top off the building, and shooting radioactive material skywards. A fire then broke out which burned for a full 9 days.
In total, over 100 times more radiation was released from the explosion than the two atomic bombs dropped in world war 2. Most of the fallout was deposited in what is now Belarus, Ukraine, and Russia, although all countries across Europe detected some degree of fallout.
The disaster was made worse by the slow response by the authorities. The nearby town of Pripyat, home to more than 49,000 people, were initially left unaware. They were told that the smoke rising from the power plant was a routine process. However, only a few hours after the explosion, people in the town started to fall ill, some fatally. It was 2pm, over 12 hours after the explosion, that people were finally being evacuated from Pripyat. People were told to only take essentials as they would return in 2-3 days. Yet as of today, Pripyat remains a ghost town.
2 people died in the initial explosion and 100 firefighters received acute radiation syndrome, killing 29 in a few months and 18 more over the following years. Beyond this, it is very difficult to tell how many died from radiation in the town of Pripyat and further afield as it is difficult to tell what number of cancers were caused as a direct result of the explosion. Estimates vary from the United Nations, which predicted 4000 deaths to Greenpeace’s estimate of 93000.
Preventing Further Damage
After the explosion, a hastily built cap was constructed around the reactor to contain further fallout leaking into the environment. This soon fell into disrepair and was replaced last year, by a cap expected to last a century, at a cost of $1.6 billion.