On April 26, 1986, Reactor No. 4 at the Chernobyl Nuclear Power Plant in Ukraine exploded during a failed safety test. The blast sent radioactive material across Europe and caused fear far beyond the Soviet Union.
About 30 people died in the immediate aftermath of the explosion and emergency response. In the years that followed, many more people suffered from radiation exposure linked to the disaster.
Critics praised the series for turning one of humanity’s darkest disasters into powerful television. Viewers responded too, and tourism to the Chernobyl Exclusion Zone, which had already been growing, increased as more people wanted to see the site for themselves.
But long before the drama series aired, one piece of real footage from inside the site had already been shared online. And in many ways, it is more unsettling than anything made for TV.
What is Chernobyl like inside?
Alexander Kupny worked as a health physics technician at Reactor No. 3 in 1989. In the late 2000s, when unauthorized visits to parts of the site had become more common, he and his friend Sergei Koshelev decided to go somewhere almost no living person has ever entered: inside Reactor No. 4 itself.
Thankfully, the pair wore as much protective gear as they could get. They also filmed what they saw, leaving behind a rare record of a place most people could never safely visit.
At first, the footage looks like someone walking through a ruined basement. There are dirty walls, broken structures, old equipment, and darkness. Then the strange static across the screen starts to stand out.
It is radiation physically interacting with the camera sensor in real time. Each tiny flash and speck of noise is a sign of something invisible, deadly, and still present in the ruined reactor.
When the footage later resurfaced on Reddit, people were stunned by what they were seeing. The plain, grim setting became much more disturbing once viewers understood what the static meant.
“Every time the camera goes over something dark, the invisible death becomes visible with all the little speckles showing on the camera,” one user wrote. “That is the radiation interacting with the sensor.”
“Crazy how it affects the camera sensor,” said another.
Kupny and Koshelev survived the visit and made it back out of the reactor.
Many of the workers who spent months in and around that destroyed reactor in 1986 were not so lucky. Their work helped contain the disaster, but many paid a terrible personal price.
How the Soviets tried to cover up Chernobyl
The Soviet authorities first tried to keep the explosion quiet, since admitting the scale of the disaster would have been devastating for their global image.
They said nothing for more than 40 hours. When they finally made a public statement, they only said two people had died and that a committee had been formed. The real situation was far worse.
A radioactive cloud moved northwest into Belarus before spreading across much of Europe. Within hours, radiation was being detected hundreds of miles away, making it impossible to hide what had happened.
Legasov died by suicide on the eve of the second anniversary of the disaster. Reports have said he had been worn down by officials refusing to act on his safety warnings.
The first Chernobyl Sarcophagus was built to cover the destroyed reactor, while the later New Safe Confinement was moved into place in 2016.
Building Chernobyl’s Sarcophagus
With the reactor still burning and radiation levels high enough to kill, Soviet engineers had one urgent task: bury the wreckage as fast as possible.
They worked at extreme speed and under extreme danger to build a steel and concrete shell around the destroyed reactor. The job was risky, but officials saw it as the only way to contain the site.
The structure took 206 days to build and used more than 400,000 cubic meters of concrete. It became known as the sarcophagus.
A more permanent replacement, the New Safe Confinement, was later built and slid over the old sarcophagus in November 2016. The huge arched structure is roughly the size of the Stade de France, cost about $1.6 billion, and was designed to last 100 years.
But the structure is now facing serious problems. In February 2025, a drone strike damaged the dome, and later inspections found that its safety functions had been compromised. Temporary repairs have been made, but full restoration work is still needed to protect the site long term.
The most dangerous object on Earth: Chernobyl’s ‘Elephant’s Foot’
When Reactor No. 4 exploded during the failed steam test at the Chernobyl Nuclear Power Plant, the amount of radiation released was enormous.
The spread of radioactive material was devastating, and radiation was later detected as far away as Sweden.
Where Reactor No. 4 once stood, the area became a toxic wasteland. Out of that destruction came what many have called one of the most dangerous objects on Earth: the Elephant’s Foot.
How was the ‘Elephant’s Foot’ formed?
Uranium fuel inside the reactor core melted after the reactor overheated. When the steam explosion tore the reactor apart, heat, steam, and molten nuclear fuel mixed into a 100-ton flow of super-hot material that moved through the building and down through the concrete floor.
The mass eventually reached the basement of the facility, where it cooled and hardened. Researchers later named it the “Elephant’s Foot” because of its large, wrinkled shape.
The deadly formation was found by brave workers and volunteers who entered the reactor months after the disaster. At the time, it was still extremely hot and weighed an estimated 2.2 tons.
It was so dense that scientists reportedly had to use a Kalashnikov assault rifle to break off pieces for analysis.
It was also measured at almost 10,000 roentgens per hour. That has been compared to millions of chest X-rays in a single hour, which shows how deadly it was at the time.
It is also believed that standing beside the toxic mass for five minutes would have left a person with only around two days to live.
What is the state of the Elephant’s Foot today?
IFLScience reports that, over time, the Elephant’s Foot has lost some of its intensity because of natural radioactive decay. That has allowed some scientists, cleanup workers, and photographers to visit the area under controlled conditions.
Still, the site is not safe in any normal sense. It is not known for certain how much radiation the mass gives off today, because it remains shielded inside the Shelter Object covering the remains of Reactor No. 4.
