Anatoly Doroshenko is assigned to enter Chernobyl’s reactor 4 to take vital radioactivity readings
Mykhaylo Palinchak
The shattered remains of Chernobyl’s reactor 4 are one of the most remote places on Earth. Not only are the ruins physically dangerous, but they are highly irradiated, pitch black and covered with crumbling, concrete sarcophagi, which are, in turn, covered with new secure confinement structure.
But it’s important that scientists understand what’s going on inside. and that work falls Anatoly DoroshenkoA young scientist at the Institute for Safety Problems of Nuclear Power Plants (ISPNPP). He has what could be considered the most dangerous job on the planet: crawling deep within the reactor ruins to take readings and samples, getting within 8 meters of the core, sometimes once a month.
“It’s not scary,” Doroshenko tells me, as he stands next to a scale model of Chernobyl in the institute’s laboratory in the exclusion zone around the plant. “I was ready for this for a long time. You just have to be in this moral position to accept it and accept the need to do it.”
“It’s really a strange feeling. I think it can be compared to the feeling of conquering Everest, flying into space or exploring the ocean floor. A certain adrenaline rush is always present.”
He has a list of tasks to complete each deep inside the reactor, but has a limited amount of time to do them, so he needs to balance haste and care. “You must have the knowledge of what you are going to do, where you are going to go. You must have control over yourself,” says Doroshenko. He repeats that second part twice, almost as a reminder to himself.
“You have to know that everything is contaminated. And if you’re touching something, you have to know what you’re touching, because you don’t want to contaminate your clothes or yourself,” he says. “The main thing is that you have to be aware of your plans, because there is not so much time that it is safe to be there. You want to work, and you also want to see something (interesting), but this is not an excursion. You are there working, so you have to be aware of everything you need to do and keep that in your mind.”
If Doroshenko is visiting less dangerous parts of the reactor, he will wear a hat, protective gloves and a respirator. In areas with greater contamination, he will also add a full-body suit, or a third layer of a polythene suit to protect against dust. She also has lead aprons that can be placed on top, but the weight and bulkiness make it difficult to deal with the tight spaces inside.
As a young scientist, he was taken by an older employee to the main circulation pumps that normally cooled Reactor 4 and were part of the safety testing that led to the 1986 disaster. “It’s a very important place to see and it’s very famous. We’re seeing all the destruction caused by the eruption.”
Inspection of the inside of the coffin containing reactor 4 in Chernobyl in 1991
Images Group/Shutterstock
“The key safety for us is the knowledge, not the suit,” the researchers say. Olena Pareniuk On ISPNP. “Anatoly is one of our key workers, and he looks tired and a little sad, as we all are, but he is doing a great job. We don’t have that many young people who are good at dosimetry measurements.”
Doroshenko’s boss, Victor KrasnovThe acting director of science at ISPNPP says generations of scientists have gone inside the reactor since 1986 to take measurements and install sensors. There, they find confined spaces, pipes filled with radioactive water, and large sections of corium – a mixture of fuel, concrete and metal melted in the 2500°C heat following the disaster, which has dripped and made its way through the ruins to form unusual shapes.
“The first people to actually go in there came up with these slang names for all these objects: elephant’s leg, cat’s house, dog’s house, octopus beam, mammoth beam,” says Krasnov. “Everything inside is destroyed, so all paths are quite challenging.”
The risks are almost endless. There is a 2200-ton upper biological shield that once stood on top of Reactor 4, and is now nicknamed Elena. It was tossed like a coin in the explosion and today rests on the debris at an angle of 15 degrees. If it were to collapse, it could leave behind precarious ruins and spread vast amounts of radioactive dust.
1986 image of the “elephant’s foot” inside Chernobyl’s reactor 4, a molten mass of nuclear fuel and other material
Photo 12 / Alamy
Part of the long-term risk, and need for regular, accurate readings, comes from occasional spikes in nuclear activity. No one knows where all the fuel material is inside the reactor, and it becomes active occasionally.
When uranium or plutonium fuel decays radioactively, it emits neutrons, which can fuel a fission reaction if the neutron is captured by another radioactive nucleus. However, large amounts of water slows down these neutrons, preventing them from being captured. Immediately after the disaster, the coffin created dry conditions inside the reactor, leading to a neutron spike.
Later, there was more water, partly because the concrete shelter was full of holes that allowed birds and weather in, so humidity became higher and neutron flux decreased. “Right now, since the new secure confinement has been installed, the humidity is low, so we are expecting that some accidents may occur and we need to know in advance,” says Krasnov. So it’s important that Doroshenko continues to dig inside to better understand the situations.
Despite the rigorous safety procedures adopted at Chernobyl, it will never be safe to crawl inside an exploded reactor. “And that’s why I’m worried about my health, because if I don’t worry about it, I can make mistakes. I don’t know if I will have health problems in the future, but I know that if I follow radiation safety standards, I can minimize these risks.”
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