Chernobyl: Fear of another explosion as nuclear reactions smolder in an inaccessible room

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Scientists say nuclear reactions have been discovered in an inaccessible room in Chernobyl that smolder “like embers at a barbecue.”

A wave of neutrons has been observed in a chamber known as Subreactor Room 305/2, 35 years after the disastrous nuclear disaster.

Neutrons are particles in an atom and are a signal of fission – the fission of an atomic nucleus, resulting in the release of large amounts of energy.

Scientists may need to intervene in the room, which has not entered since the disaster, to prevent another explosion.

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in April 1986, a sudden power surge at the Chernobyl nuclear power plant resulted in a massive reactor explosion, exposing the core and covering the western Soviet Union and Europe with radiation

in April 1986, a sudden power surge at the Chernobyl nuclear power plant resulted in a massive reactor explosion, exposing the core and covering the western Soviet Union and Europe with radiation

LFCMs at CHERNOBYL

The formation of LFCMs in Chernobyl is well known and the problems they pose are well documented.

LFCMs are a mixture of highly radioactive molten fuel and building materials that fuse together.

For example, during the meltdown of the Chernobyl reactor core, temperatures rose above 1600 ° C and the uranium fuel melted with the zirconium coating.

This formed a radioactive molten slurry that remained at an extremely high temperature. Propelled by its own weight, it mixed with steel, concrete, serpentine and sand.

The 100-ton mass of the glassy lava then spread to sub-reactor chambers, solidified into large masses, creating the infamous ‘elephant foot’, among other things.

“We only have assumptions,” said Maxim Saveliev of the Institute for Safety Problems of Nuclear Power Plants (ISPNPP) in Kiev, Ukraine. Science Magazine.

‘There are many uncertainties, but we cannot rule out an accident.’

Neil Hyatt, a nuclear materials chemist at the University of Sheffield, said the situation was like “the embers in a barbecue pit.”

“It reminds us that it is not a problem that has been solved, it is a stabilized problem,” he said.

The scientists use sensors to track a rise in the number of neutrons in the chamber, but they are slowly rising, suggesting there are still a few more years to figure out how to quell the threat, Science Magazine said.

The Chernobyl disaster occurred on April 26, 1986 at unit number four at the Chernobyl nuclear power plant, near the Ukrainian city of Pripyat.

The personnel on duty made mistakes during a safety test that triggered the nuclear reactor explosion – a fatal error documented in a recent HBO series.

The explosion that covers the western Soviet Union and Europe with radiation – leading to the largest man-made environmental disaster in history – and the greatest nuclear disaster ever.

More than 100,000 people were evacuated and a 20-mile exclusion zone was established that still exists.

Radioactive corridors where reactor No. 4 malfunctioned at the Chernobyl nuclear power plant - and the radiation levels are fifty thousand times higher than normal

Radioactive corridors where reactor No. 4 malfunctioned at the Chernobyl nuclear power plant – and the radiation levels are fifty thousand times higher than normal

At the time, emergency services responding to the accident used helicopters to pour sand and boron on the reactor waste to extinguish fires.

The sand melted with uranium fuel rods and their zirconium coating, as well as graphite control rods, to form a lava.

The lava poured into the basement chambers of the reactor hall and hardened into highly radioactive formations called lava-like fuel-containing materials (LFCMs).

A few weeks after the accident, crews completely covered the damaged unit in a temporary concrete structure called the ‘sarcophagus’ to limit the release of radioactive material.

The Soviet government also cut down and buried about a square mile of pine forest near the plant to reduce radioactive contamination at and near the site.

The sequence of events that led to the reactor explosion in Reactor 4 on the night of April 26, 1986

The sequence of events that led to the reactor explosion in Reactor 4 on the night of April 26, 1986

A sudden power surge at the Chernobyl nuclear power plant resulted in a massive reactor explosion, exposing the core and covering the western Soviet Union and Europe with radiation.  Pictured is a view of the Chernobyl nuclear power plant three days after the explosion on April 29, 1986

A sudden power surge at the Chernobyl nuclear power plant resulted in a massive reactor explosion, exposing the core and covering the western Soviet Union and Europe with radiation. Pictured is a view of the Chernobyl nuclear power plant three days after the explosion on April 29, 1986

But the problem is that rainwater can enter the sarcophagus, causing the number of neutrons to rise enormously.

The factory has since installed nozzles that emit gadolinium nitrate, which absorbs neutrons – but they can’t enter some basement rooms.

In 2016, the New Safe Confinement (NSC) – a massive structure built to contain the remains of the No. 4 reactor unit – was installed above the sarcophagus to keep rain out.

The New Safe Confinement (NSC, pictured) is a structure built to confine the remains of unit number four in Chernobyl

The New Safe Confinement (NSC, pictured) is a structure built to confine the remains of unit number four in Chernobyl

Since then, neutrons have been stable or declining in most regions – but not in sub-reactor chamber 305/2, where they mysteriously nearly doubled in four years.

“It’s just not clear what the mechanism could be,” Hyatt said – but there is a concern that the room may become a bigger threat as it dries, leading to an uncontrolled release of nuclear power.

While any explosive reaction would be contained by the NSC, it could threaten to tear down unstable parts of the aging sarcophagus and fill the NSC with radioactive dust.

There is no chance of a recurrence of the catastrophic explosion, in which two reactor workers were killed on site and a further 134 hospitalized with acute radiation poisoning.

But experts are considering sending in a specially developed radiation-resistant robot that can insert drill cylinders, which would suck up neutrons.

WHAT HAPPENED DURING THE 1986 NUCLEAR DISASTER?

On April 26, 1986, a power plant on the outskirts of Pripyat had a massive accident in which one of the reactors caught fire and exploded, spreading radioactive material into the surrounding area.

More than 160,000 residents of the city and surrounding areas had to be evacuated and unable to return, leaving the former Soviet site as a radioactive ghost town.

Last year, NASA scientists sent eight fungal species from the Chernobyl exclusion zone (shown in red) into space, where they were placed aboard the International Space Station.

A map of the Chernobyl Exclusion Zone is shown above. The ‘ghost town’ Pripyat is close to the site of the disaster

The exclusion zone, which covers a significant area in Ukraine and part of neighboring Belarus, will remain in effect for generations to come, until the level of radiation falls to a level that is safe enough.

The area is called a ‘dead zone’ because of the extensive radiation that persists.

However, the proliferation of wildlife in the area contradicts this and many argue that the region should be turned over to the animals that have settled in the area – creating a radioactive protected wildlife sanctuary.

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