Scientists monitoring the Chernobyl nuclear power plant say nuclear fission reactions are happening again in the remains of the reactor hall – 35 years after the core melted. .
35 years after the Chernobyl Nuclear Power Plant in Ukraine exploded in the world’s worst nuclear accident, fission reactions smoldered again in the uranium fuel blocks, which were ‘buried’ outside. in the reactor hall. Accordingly, the sensors of the Chernobyl monitoring agency are measuring an increase in neutrons coming from one of the inaccessible areas of the plant, indicating signs of a fission reaction taking place. out.
It is known that scientist Anatolii Doroshenko of the Institute for the Study of Safety Problems of Nuclear Power Plants (ISPNPP) in Kyiv, Ukraine, reported the problem last week during discussions about the dismantling. reactor.
“There’s a lot of uncertainty. But we can’t rule out the possibility that [one] more accident could happen,” said Maxim Saveliev, a researcher at ISPNPP.
The number of neutrons is slowing down, Mr. Saveliev said, suggesting that Ukraine’s authorities are still several years away from figuring out how to contain the threat.
About 95% of the initial fuel from the reactor is believed to have flowed into the basement rooms of the plant after the April 1986 disaster. They form compounds known as fuel containment materials. (FCM).
A year after the incident, a giant barrier made of steel and concrete, named “Coffin” was placed atop the rest of the reactor to prevent radiation from the FCMs from escaping. In 2016, the New Secure Confinement Facility (NSC) – a giant shielding structure – was placed over both the Shelter and the reactor was built at a cost of more than 1.5 billion Euros.
Since then, the number of neutrons has stabilized in most areas of the plant. However, the amount of neutrons again began to nearly double in four years, at some point like in room 305/2 of the reactor. This is also where tons of FCMs are buried.
Speaking to Science Mag, Neil Hyatt, a nuclear materials chemist at the University of Sheffield, described the situation inside the reactor hall: “It’s like embers in a barbecue grill.”
While there is no danger of a continent-wide nuclear explosion as was the case in 1986, expert Neil Hyatt believes the exponential increase in fission could cause ‘the release of uncontrollable nuclear energy’.
Experts also fear an explosion could cause a partial collapse of the old shielding, filling the NSC shield with ‘fallout.’
Currently, Ukrainian authorities are trying to determine if the reactions will go away on their own – or if special interventions are needed to prevent another accident from happening.
In fact, Ukraine has been looking to get rid of FCMs before they reach serious levels in the next few years. The government is expected to come up with the settlement measures by the end of the year. Current radiation levels are too dangerous for humans to take on their own to stabilize FCMs that cause fission. Thus, one option being worked on is to develop a radiation-resistant robot to drill into the FCM and insert boron cylinders, which function like neutron-collecting control rods in a reactor.