Chernobyl: Why the nuclear power plant continued to operate after the accident and when it was no longer radioactive

Chernobyl recently experienced some of its most stressful moments since the 1986 disaster.

At the beginning of the Ukrainian invasion, Russian troops captured the plant and its environs in late February, and the Ukrainians recaptured the territory a month later.

These events draw attention again to the plant where the worst nuclear disaster in history took place.

The International Atomic Energy Agency (IAEA) and the World Health Organization (WHO) estimate that the April 26, 1986 crash caused 56 direct deaths and at least 4,000 deaths among workers and locals.

It left a 30-kilometer perimeter around Pribat, a plant-operated town about 100 kilometers north of Q, which is almost uninhabitable. This is called the exclusion zone.

The events of 1986, which were covered up by the Soviet Union at the time, were widely documented in later years and reached the public in a variety of forms, from reports to books to HBO’s hit 2019 miniseries.

However, Little is known about the history of Chernobyl after the accident.

The recent invasion of the Russian military illustrates something that many have ignored: the nuclear power plant has not been sealed and closed, but is still connected to the power grid and more than 2,000 workers continue to work.

In fact, after Reactor No. 4 exploded in 1986, Continued to generate electricity for nearly a decade and a half With the remaining three units.

This raises some questions about Chernobyl after the disaster, now in the midst of the conflict between Russia and Ukraine, and its future.

For 14 years and 7 months, first the Soviet Union and then Ukraine had facilities in place to guarantee the region’s electricity supply.

This has made neighboring countries anxious. Fear of a new accident In Soviet RBMK-100 furnaces, tempered with graphite, due to design defects.

In fact, when did the alarms go off in 1991? A turbine of reactor No. 2 caught fireThis led to the closure of the facility, while No. 1 was closed in 1996, five years later.

After several years of negotiations, Ukraine agreed with the G7 to decommission the plant in exchange for assistance of 1,500 million euros (approximately US $ 1,650 million), and on December 12, 2000, Reactor No. 3 was finally operational. It was definitely turned off.

As for the unfortunate Reactor 4, it was after the accident Exposed more than 200 tons of radioactive materialIn late 1986, to prevent leakage, it was urgently sealed with steel and concrete sarcophagus.

But it was a temporary shell, hastily built to last a maximum of 30 years. Radiation, snow, rain and wind made it worse In 2013, one of the walls and part of the roof collapsed.

In 2016, after seven years of work, the NSC (abbreviation “New Safe Prison” in English) was opened, designed to contain radioactive remains. For a century.

It should be noted that the Chernobyl plant is located in the center of the exclusion zone All human activities were prohibited Except for working in a very dangerous place: a nuclear power plant.

“Despite the high levels of radiation to current working standards, this allowed operators’ normal work without endangering them,” Argentine nuclear engineer Aníbal Blanco explains to BBC Mundo, a researcher at the National Atomic Energy Agency (CNEA). ) And specializes in the Chernobyl accident.

However, the expert points out that “in accordance with current international regulations on radiation protection for workers in the nuclear sector, In that situation work will not be allowed today”.

During those years the staff at the nuclear plant stayed in their positions for shorter shifts and constantly calculated their radiation exposure.

Although it has not produced electricity since 2000, Chernobyl It cannot be removed and requires constant management.

“All the people working at the Chernobyl nuclear power plant We must continue to work to eliminate the effects of the 1986 disasterதுணை, Deputy Ihor Kryvosheyev, chairman of the committee to repair the damage caused by the Chernobyl accident in the Ukrainian parliament, told BBC Mundo.

The plant says it “now aims to ensure nuclear safety” within the limited reactor 4. The splitting reactions continue By the concentration of radioactive elements.

About 2,400 employees are registered at the plant, ranging from scientists and technicians to chefs, doctors, paramedics and members of the National Guard.

The former carries out many essential tasks, such as the replacement of nuclear fuels or the maintenance of facilities containing sarcophagus and radioactive waste.

These jobs require constant electricity.

When Russian troops arrived in the Prypyat area on February 24, the power outage, which lasted several hours, was forced to use emergency diesel generators without any serious danger.

However, whatever happens due to conflict or some other reason The power will be cut off for several days or weeks?

Aníbal Blanco warns that “this should not happen in any of these facilities.”

“In the worst case scenario – total power loss for several days – the water in the pools will evaporate and the spent fuel components (ECG) will be released into the air,” he explains.

Exposure to such substances “raises the ambient radiation and overheats the ECGs, causing cracking and release of radioactive particles into the environment,” he says.

Kryvosheyev, for his part, believes the disaster could be huge.

“If the ventilation system of NSC 4 of the reactor does not work and the power is cut off for a long time, the radioactive dust will spread beyond the sarcophagus and beyond the exclusion zone. Pollutes clean areas of Ukraine and Europe”.

Arrival of Russian troops at the end of February Caused a sharp and sudden increase in radiation levels In the zone.

This created fears that a radioactive leak could be caused by the impact of a projectile or explosive on the plant.

However, that is not the reason for it. The passage of troops and heavy vehicles in the first phase of the war raised dust in the exclusion zone, where radioactive material accumulated.

“That radioactive dust in the environment sets alarms on the detectors. Then, when troops and vehicles are stopped, it fades and the radiation level drops to a previous level,” says Blanco.

When Russian troops captured Chernobyl There were about 200 workersWho was in the facility for 25 days until his release on March 20.

They kept 169 Ukrainian national guards in the facility of the plant and then took them prisoners to Russia, kyiv officials said.

“They were taken hostage and forcibly taken away,” the Ukrainian deputy condemned.

Kryvosheyev accuses the Russian military of using the exemption zone “as a military base to store ammunition and ammunition”, which he believes could lead to a nuclear disaster that could have “devastating consequences for Europe and the entire planet.”

Russian officials, for their part, promised to guarantee the power supply to the plant, and pointed out that Ukraine was responsible for any incident that might take place there.

However, on April 1, Ukraine reasserted control of the plant.

Ukraine’s state nuclear company, Energoatom, claimed to be Russian soldiers “Significant levels” of radiation were revealed When you stay for more than a month.

The plant will be completely eliminated in 2064. Why so long?

Aníbal Blanco argues that job removal is “very complicated and requires careful planning”.

“The sarcophagus construction of Reactor 4 involves not only maintaining the areas where radioactive waste and units 1 to 3 have spent the deposited fuel, but also replacing these used fuels and then gradually disposing of 3 units of unused sites.

Krivoshev, for his part, promises 2064.This is a reference date only”.

“Our scientists have developed a plan with steps to implement until that year, and our state is ready to fund and implement those activities.”

Anyway, he says, “The Chernobyl problem Stay here for thousands of years”.