On April 26th, 1986, one infamous event rocked the world. It seemed like any other day before Ukraine’s Chernobyl Nuclear Power Plant exploded in the wee hours. It has been 34 years since that unfaithful day. However, even after heaps of government investigation and scientific research, several questions about the accident lie unanswered.
Let us dig deeper into the Chernobyl accident – the worst ever nuclear disaster to hit our planet.
Where is Chernobyl?
According to the World Nuclear Association, the Chernobyl nuclear power plant is located about 81 miles north of Kuev, Ukraine. It is around 12 miles away from the border of Belarus on the south as well. The power plant has four reactors built during the 1970s and 1980s. It also possesses a human-made reservoir, fed by the Pripyat River. Designed to cool the reactors, the reservoir is close to 8.5 square miles.
At the time, Pripyat was a newborn city and at just 2 miles away, it was the closest to the power plant. The town had around 50,000 residents in 1986. Chernobyl, however, was an older and much smaller town. It was around 9 miles from the powerplant and housed about 12,000 people. The rest of the area is comprised of woodland and farms.
The power plant
As mentioned previously, the Chernobyl plant used four RBMK-1000 nuclear reactors, designed by the Soviets. However, now, all engineers and scientists are aware that this design is flawed. Made in the form of a pressure tube, the reactors used an enriched U-235 uranium dioxide. This was utilised as a fuel to heat the water, producing steam to run the turbines and produce electricity.
Most nuclear reactors use water to control the atomic core’s reactivity by getting rid of excess steam and heat. However, the RBMK-1000 reactors used graphite instead to maintain an ongoing reaction in the centre. In this way, the core is heated and more steam bubbles are produced. Thus, making the nuclear core more reactive and not less. According to engineers, in this circumstance, a positive-feedback loop is created called a “positive-void coefficient.”
Explosion at the Chernobyl nuclear power plant
As per the reports of the U.N. Scientific Committee on the Effects of Atomic Radiation, the explosion occurred on April 26th, 1986, during a routine maintenance check. There was a compromise in safety regulations as operators turned off vital control systems for the electrical systems to be tested. Hence, causing the reactor to attain dangerously low power and varying levels.
Nuclear Energy Agency says that the fourth reactor was shut down the previous day to carry out maintenance checks. Although there is some dilemma about the cause of the explosion, most people believe it was first caused due to excess steam and then because of hydrogen’s influence. The positive void coefficient caused the increase in steam, which caused a large power surge that the operators could not control.
The explosions occurred at 1.23 am with the destruction of reactor four and a fire. The radioactive debris from the plant began to rain over the area and adjacent buildings caught fire. This was only the start of a catastrophic event as the wind carried toxic fumes and dust.
Within a few hours of the accident, two operators were killed. Over the next several days, the death toll of the plant workers climbed due to radioactive sickness. Emergency crews made efforts to contain the radiation leaks and fires, but in vain.
Although the initial fire was put off around 5 am, it took ten days and 250 firefighters to stifle the fire from the graphite fuel.
Most of the radiation leaks were from iodine-131, cesium-134, and cesium-13, which were fission products. Although Iodine-131 has a shorter half-life of eight days, it quickly settled itself in the thyroid gland as it was present in the air. However, what was more alarming is that Iodine-131 isotopes have longer half-lives, around 30 years. So, their leaks were extremely hazardous.
After 36 hours of the accident, evacuations began in Pripyat. But, sadly, by then, most of the population complained of headaches and vomiting. The officials closed 18 miles of the area surrounding the plant. Later on, the emergency crew evacuated 16,000 residents.
According to the U.S. Nuclear Regulatory Commission, twenty-eight workers of the plant died within four months. This included some brave ones who put their lives at risk to prevent any further leaks.
During the explosion, the winds were mostly from the east and south. So, most of the radiation travelled northwest toward Belarus. But, the Soviet authorities did not inform the rest of the world about the severity of the situation right away. However, when Sweden revealed concerns about the leak in their country, scientists could conclude more details regarding the explosion. According to the United Nations, the Soviet authorities were then forced to reveal information about the full crisis’s extent.
A total of 31 people died within three months of the accident. As for those below the age of 18 during the explosion, between 1991 and 2015, almost 20,000 of them were diagnosed with thyroid complications. Although there may be additional cancer cases and other life long effects from the accident, the overall number is much lower than feared initially.
Some experts feel that the fear of poisoning led to tremendous suffering than the disaster itself. For instance, several doctors advised pregnant women to undergo abortions to remove the risk of delivering children with congenital disabilities. However, in reality, the level of radiation was far too low to cause any concerns.
Shortly after the accident, trees around the area died due to radiation. The region, known as the “Red Forest” is because of the trees’ bright ginger colour. Later, officials buried them to avoid any further danger. Pripyat, Chernobyl and 1000 miles surrounding the plant is an “exclusion zone,” where only scientists and government officials visit.
Despite the risks, the power plant supplied power to the country. In December 2000, it stopped functioning after the shutting down of the last reactor.
Today, due to humans’ absence, the area is rich in wildlife like wolves, deer, lynx, beaver, eagles, boars, elk, and bears. However, some areas with high radiation show stunted trees. The site, although shows recovery, is not even close to normal.
Since the catastrophe, several safety regulations were revised and implemented. Programs such as the International Atomic Energy Agency (IAEA) and the World Association of Nuclear Operators formed. Modification of the RBMK reactors happened to increase safety around the world.