O Chernobyl accident it was the biggest nuclear accident in the history of the whole world. It took place in the then mighty and imposing Soviet Union that boasted power and ascendancy in all its achievements.
Index
On April 26, 1986 in the city of Priopyat, 20 km from the city of Chernobyl, in the then Soviet Union, which was extinct and now belongs to Ukraine, everyone went on with their lives without imagining that the 1:23:47 Mon. from the dawn of that day, the horror of destruction and death would arrive.
In reactor 4 of the V.I.Lenin nuclear power plant, during a safety test, a serious explosion occurred which resulted, in the first instance, in the death of two men and a fire that lasted for days.
Upon completion of the scientific expertise on site, it was found that the cause was pure human error. Because the RBMK reactor, used in plants in the Soviet Union, had a serious error in the design of its creation, being the main cause of the tragedy.
With the big explosion, the reactor was exposed, throwing tons of reactive material into the atmosphere. The wind contributed to this radioactive material being carried to the northern and western regions of the city of Prypyat and from there, it spread throughout the world.
In a short time, high levels of radiation were identified in Belarus, Sweden, Poland, Austria and in more distant places such as Canada, the United Kingdom and the United States.
Sweden was the first country to warn the world that something very serious and bad had happened in the Soviet Union.
Before that, the Soviets were trying to hide the problem of Chernobyl accident and sort of silently resolve so as not to damage your nation's reputation.
The Chernobyl plant worked just like the other nuclear plants, the fissile fuels were stored in the reactor.
The reactor caused the energy created by the fission of the unstable elements, plutonium and uranium, to heat and evaporate pure water at 270°C. This water reaches very high temperatures.
And because of that, when this heated water is released, it moves the turbines that are connected to the generator. And these generators, which work like big magnets, are wrapped in a lot of conducting coils.
Electric current is generated by the phenomenon of electromagnetic induction, while the generator works, the electric current is in motion.
At the plant there were 4 RBMK-1000 nuclear reactors that could generate 1000 MW of electrical energy per reactor. At the time of the Chernobyl accident, the plant produced 10% of the country's electricity.
The plant was also the third nuclear plant produced in the Soviet Union and which used RBMK reactors, that had an outdated technology, as they had been produced 30 years before the terrible date of the tragedy.
Inside the reactors there were hundreds of uranium 235 pellets. They were on long metallic rods, dipped in a tank of distilled water that was used to regulate the nuclear fission system.
Each reactor was covered with a thick, large layer of graphite. The four reactors at the Chernobyl plant were produced between 1970 and 1977 and the graphite surrounding the reactors moderated the nuclear reactions.
This moderation exerted deceleration of the neutrons emitted in the nuclear cracks, transforming the component into thermal neutrons that were transferred to the graphite in the form of heat.
And when it comes into contact with graphite, the water also absorbed heat and had its evaporation in a controlled manner. Today it is known that these reactors are not 100% safe when working at low power.
The graphite covering the reactors moderates an excess amount of neutrons, releasing too much heat. And in this way, the water vapor inside the reactor and the internal pressure increases.
The water vapor is insufficient compared to the amount of water in its liquid state used to cool the fuel cells. And so, the chain reaction gains acceleration until its moderation is impossible.
Other than that, the Chernobyl reactors needed an essential device to prevent leakage of radioactive material: a steel and concrete dome for containment.
O Chernobyl accident was a list of human errors with breach of security measures. On the fateful day, a text was written on the turbines of reactor 4.
This is to know how long the turbines would be able to continue operating with an abrupt power outage. This test would have been done a year earlier and it was noticed that the turbines stopped too quickly.
And to solve this problem, new devices were installed and needed testing. The plant operator did not deactivate the reactor's automatic shutdown system. When he realized it, it was too late.
The nuclear reaction was very unstable and the amount of energy produced was 100x more than its always used power. So the plant technicians made a decision: to pump xenon gas inside the rods.
These pellets had 210 tons of uranium 235 and had the capacity to absorb neutrons emitted by nuclear fission. It was not possible to control the fission using xenon to stabilize the reactor.
In an act of desperation, boron-containing rods were manually placed in an attempt to curb neutron emission. But when these rods were inserted, they expelled a certain amount of water into the reactor.
The remaining water heated and evaporated, expanding violently. The pressure that was produced by this water, loosened the plate that covered the reactor that weighed 1000 tons.
A large volume of vapor containing cesium137, strontium 90 and iodine 131 was released into the atmosphere. And two seconds later came the second explosion that ejected fragments from the fuel pellets.
And with the explosion, heated graphite fragments were also ejected, totaling 300 kg of carbon fragments. The frame reactor core, due to the absurd temperature, melted and became incandescent, starting a huge fire.
And contaminated clouds, laden with radioactive material, took over the skies, with several radioisotopes and after this second explosion, the reactor was compromised.
A total of 300 tons of water per hour were used in an attempt to lower the reactor temperature. Until the tenth day of chernobyl accident, about 5000 tons of boron, dolomite, lead and clay were poured into the reactor.
O Chernobyl accident released about 100 MCI (megCuries) being considered the biggest radioactive accident of humanity and making the city a ghost territory.
____
Subscribe to our email list and receive interesting information and updates in your email inbox
Thanks for signing up.
