Welcome to: the self-talking president
Today, let’s talk about the story of elephant foot, elephant foot is Chernobyl nuclear accident melted furnace core .
We are more familiar with these stories about Chernobyl, such as how soldiers rescued disasters, how 160,000 square kilometers became a forbidden zone for humans, how tens of thousands of people were tortured by nuclear radiation, etc. These stories happened on the ground.
But have you ever wondered what kind of story is happening under the ground, in those invisible places, and the melted furnace core?
Elephant foot
The first time someone saw it was in the 6th month after the explosion. In the autumn of 1986, a rescue team went deep underground and they saw it from a remote camera. This pool of solidified lava is like an elephant's foot, and the radiation value around the elephant's foot is as high as 12,000 roentgens per hour.
That is to say, if you approach it,
30 seconds, there will be blurred vision due to lens damage within a week;
two minutes, your cells will begin to collapse, internal organs And the skin began to bleed;
four minutes, vomiting and diarrhea came, the body began to leak like a sieve;
five minutes, then you have about 40 hours.
The rescuers retracted their cameras from the corner. They knew that they were facing the deadliest thing in the world.
But they have to do something...
explosion
Six months ago,On April 26, 1986, at 00:05, the reactor exploded. The 2,000-ton lid on it was blown up and the entire building was broken down.
Then, the condensate in the pipe poured back, and the high temperature of thousands of degrees in the reactor caused condensate water to instantly turn into steam, so the second explosion occurred again, this time the cover was lost The nuclear fuel was sprayed directly into the air, and the fire was spreading. Residents walked to the street and watched the fire from a distance. Firefighters also rushed to the scene, but they didn’t know that the air was already full at this time. Radioactive dust.
The following are the rescue stories we are familiar with-firefighters who sacrificed, a company of heroes rushing upstairs, the evacuation of more than 100,000 people, and a radiation exclusion zone that has been closed until now.
In fact, these stories revolve around the nuclear fuel that was bombed into the sky at that time. The nuclear fuel that was bombed into the sky is 5% of the entire core fuel, and 95% remains in the reactor. It melts the core, swallows cement, glass, and pipes along the way, and spreads downwards like volcanic lava.
At the bottom, the elephant foot is condensed in the pipe of corridor 217.
These substances composed of the meltdown of the core have a special term called Corium, which is one of the deadliest substances in the world.
In reality, there have been only five Krems in total, and the first appeared in the 1979 Three Mile Island nuclear accident in the United States.
The second one appeared in the Chernobyl accident.
The other three were all produced in the 2011 Fukushima nuclear accident .
Krem is always accompanied by a nuclear reaction,Its temperature is very high and its radiation is extremely strong. The only time humans observed it up close was in the Argonne laboratory. Scientists sealed the 2000℃ Krem in a container and took this video. Finally Dip Krem into the water, killing it completely.
The robots of the Fukushima Nuclear Power Plant have also sneaked into the reactor and filmed Krem's video.
Rescue Team
Back to the previous story, in the autumn of 1986, after seeing the elephant's feet, the rescue team decided to continue sampling and take it back to the laboratory for analysis.
So they sent out the remote control car again, and wanted to use the drill on the car to sample.
There was a high temperature around the elephant's foot. When the drill bit touched the elephant's foot, it was found that the inside of the object still maintained a high temperature of 300°C, and the drill couldn't move it at all.
How to sample?
According to the records on the Russian Encyclopedia, at that time, a marksman took out an AK rifle, loaded armor-piercing bullets, and began to skillfully shoot elephant feet from a distance...
This method worked. The fragments from the elephant’s feet splashed out, and the remote control car went to retrieve the fragments.
The rescue team continues to move forward, while the members of the team are receiving high-intensity radiation.
Radiation
In the previous story, we talked about Ouchi, Srotin and Bukowski, and all mentioned the principle of radiation death.
In fact, radiation is divided into non-ionizing radiation and ionizing radiation .
The sign of non-ionizing radiation is such a graphic like WIFI, high-voltage electricity, radio, microwave oven, electric light, and even visible light,They are all emitting non-ionizing radiation, which is safe.
The sign of ionizing radiation is this commonly known nuclear radiation pattern. X-ray film, CT, and radiotherapy are all ionizing radiation, and the most lethal of ionizing radiation is the release of nuclear materials. Sub-radiation.
These neutrons are very dangerous, they will bombard the chromosomes in human cells, and our DNA is stored in these chromosomes.
Originally, if one or two points on the DNA are broken, the body is capable of repairing it. After the repair, the cell is not damaged. It is still the same as before. It divides and proliferates according to the DNA blueprint to ensure the normal operation of the human body. .
But if there are too many dead spots on the DNA, for example, bombarded by a large number of neutrons, at this time, the body cannot repair the DNA, so the broken DNA will cause chromosomal aberrations.
Once the chromosome is aberrated, there are two endings waiting for the cell:
The first is the death of the cell on the spot. If a large number of cells in the body are directly killed by neutrons in a high-intensity radiation environment, Cherno will appear. In Bailey's movie, the scene where a fireman suddenly falls to the ground as he walks.
The second is that the cell survived after chromosome aberrations, but at this time, there are two more cell fates.
The first is that the aberration is too severe, and the cells can no longer divide and proliferate normally. Therefore, these cells will naturally die after their lifespan expires, and there will be no new cells to supplement.
If there are too many cells that cannot be renewed, then the human body will experience a little bit of rotting of internal organs, organs, and flesh and blood. Skin and internal organs are all cells that renew very quickly, so they will be the first to rot But the brain cells, nerve cells and cardiomyocytes are very slow renewal cells.Therefore, they will ensure that you are not dead while the skin and internal organs are rotted a little bit, and they will also ensure that your consciousness is clear. You can only watch your body turn into a sieve little by little.
The firefighters of Ouchi, Slotin and Chernobyl have all experienced this horrible torture.
After chromosome aberration, cells have a second fate, which is slightly better than not being able to replicate. They can barely divide and proliferate according to the aberrant chromosomes, and these abnormal chromosomes will also be passed on to the next generation. Cells, therefore, in the process of replication of this deformity, a new generation of cells can easily become cancer cells, leading to an outbreak of cancer in the human body.
However, even if the new generation of cells does not become cancer cells, there will be some functional problems. If there are more cells, it will easily lead to the disorder of human tissues and organs and cause loss of function. Diseases seriously affect life expectancy.
This is the real reason why the officers and soldiers who participated in the rescue and nearby residents died very early in the future.
The mission of the rescue team
The rescue team walked around the elephant's feet with radiation. We don't know what the final fate of the team members will be.
But the rescue team brought back two important data from the ground.
First, the elephant foot is still in the building, which is much better than the worst-case scenario imagined by the scientists. It will not penetrate the foundation and penetrate into the groundwater veins for the time being.
Second, the samples and field data of the elephant foot are brought back. These data show that the elephant foot has cooled down and it is almost impossible for it to sink in the future.
Why do elephant feet cool so fast? I didn’t say that it will continue to have a nuclear reaction.Will it swallow everything on the road?
Friends who have watched the Chernobyl movie would have thought of it. Behind this, it is actually because more than 400 coal workers went into the rescue immediately after the accident.
They withstood the ultra-high-intensity radiation and the underground high temperature of nearly 50 ℃. It took only one and a half months. Before June 24, they dug a 168-meter-long tunnel and placed it on the elephant’s foot. A cooling layer was built below.
Then, relying on this cooling layer, in late November, Chernobyl was covered by the Soviets with an entire sarcophagus. This sarcophagus consumed 400,000 cubic meters of concrete and more than 7,300 Tons of steel, it eventually sealed up 740,000 cubic meters of contaminated buildings and soil to prevent nuclear radiation from being released again.
This was a big battle that mobilized 350,000 people. On the surface, everything was safe, the radiation source was sealed, and the personnel were evacuated.
But in fact, in the sarcophagus, the story of the elephant's foot is not over yet. It lies on the body of Chernobyl and continues to survive, still emitting radiation day and night.
1996
In 1996, Elephant Foot welcomed another visitor. He was called Artur Korneyev. He was 47 years old at the time and was a Kazakh radiation expert.
He rushed to the scene to support soon after the Chernobyl nuclear accident, and later continued to participate in the design and construction of the sarcophagus. He knew the status of the sarcophagus very well.
In the sarcophagus, more than 200 tons of Krem are sealed in total.
Ten years have passed, and the sarcophagus, which was originally expected to be guaranteed for 20-30 years, is in jeopardy in Konev's view.
So,He decided to go deep inside the sarcophagus, find the elephant's feet, investigate and reassess the risk.
Then, he flashed his torch and fumbled forward in the sarcophagus...
Originally, we didn't know the story after this, and Konev's name never appeared again.
The only thing we know is that after the Konev expedition, in 1998, Europe decided to help Chernobyl rebuild a protective shield to protect the sarcophagus.
Maybe Konev used his life in exchange for the precious data for building the protective cover.
But it wasn't until eight years ago, in 2013, that someone suddenly posted this photo on the Internet.
There is a strange graininess in the photo, as well as ghostly flashes.
In the beginning, netizens said that this is definitely a PS work, and deliberately used this underworld filter to scare people.
It is impossible for anyone to approach the elephant's foot. If this is true, then both the person and the photographer in the photo are committing suicide, and it is impossible for anyone to have seen the elephant's foot alive.
But then it turned out that this photo was real and it was dug up from the database of the International Nuclear Safety Commission (INSP) by a reporter.
Now this website is still accessible, but you need permission to view the big picture, and friends who are interested can check it (https://insp.pnnl.gov/-library-uk_ch_6.htm).
While digging up this photo, the reporter also found that the original title of this photo read: Project Deputy Director, Artur Konev, is examining elephant feet, the photographer is ominous, autumn 1996.
Artur Korneev, Deputy Director of Shelter Object, viewing the ‘elephants foot’ lava flow, Chornobyl NPP. Photographer: Unknown. Fall 1996.
It is precisely because of this title,Konev's story has returned to our field of vision.
It turns out that he was so close to the elephant's feet. Is he still alive? Or does he have colleagues?
In 2014, a reporter from The New York Times (Henry Fountain) found Konev himself in Ukraine. Fortunately, he was a weak but healthy 65-year-old man. Everything was normal except for cataracts.
Finally, Konev told the origin of these photos. Back then, he went into the elephant feet room by himself, calmly detected the data, and left this famous selfie with an automatic camera and flashlight. , The graininess in the photo was due to neutrons bombarding the film, and the ghost flash was due to insufficient lighting from the flashlight at the time, and Konev used a long exposure. There is no second photographer nearby to take pictures for him.
At that time, the temperature in the elephant’s foot room was significantly higher than outside, which proved that the nuclear reaction in the elephant’s foot had not been completely extinguished...
Konev went on to say that he was able to survive because in 1996, Elephant feet have been cooling for 10 years, and the radiation value is not so high.
710 rule
The specific reason is that there is a 710 rule in nuclear radiation. This is that technical experts like Konev have summed up their experience through a lot of practice.
That is, from the first few days after the explosion, for every 7 times the number of hours increases, the radiation dose will be reduced by 10 times.
For example, it took 7 hours to reduce the radiation dose from 1000 roentgens per hour to 100 roentgens per hour. Then, it takes about 7 times as much as 7 hours to reduce from 100 roentgens to 10 roentgens, which is 49 hours.
Konev calculated according to this law, and the radiation dose in the elephant foot room is already safe.
So, he dared to enter the room alone to collect data and take photos.
The final facts also prove thatKonev's estimate is not wrong.
Safety Dome
After Konev's expedition, construction of the safety dome began. This is a large arch with a height of 110 meters, a width of 257 meters and a length of 165 meters, using more than 3,600 tons of steel.
Inside the arch, there is enough to house the Statue of Liberty and a Colosseum .
The arch is first made in the factory, and then transported to the 180-meter track west of the No. 4 reactor for installation. After installation, it is moved across the track to the top of the No. 4 reactor to cover it. The
project took more than 20 years and was completed by the end of 2018.
During the construction process, some engineers still need to enter the sarcophagus to monitor real-time data.
Among them, there is an engineer named Alexander Kupnyi. He was interviewed by the media and posted a video of himself entering the sarcophagus in 2009 on the Internet.
From this video, we saw the elephant’s feet again. At this time, the temperature of the elephant’s feet was only a few degrees higher than the surroundings. Kupney said that the air around the elephant’s feet tasted a bit sweet. Feel like ozone.
Kupni also said that these engineers are not afraid of elephant feet and radiation, because these radiation doses can be assessed, experience and calculations can allow them to avoid harm, but they are most afraid of, It's actually rainwater.
In 1990, a heavy rain suddenly hit the sarcophagus. At that time, a colleague of Kupney rushed into the reactor hall with radiation.Spray the gadolinium nitrate solution. A few years later, automatic spraying equipment was finally installed in the sarcophagus, but the colleague was already sick and died in 2002.
Originally, this story is like those Soviet soldiers who rushed to the top of the building. We would think that it is a rescue story that has passed. Behind the disaster, these heroes are silently taking on it.
However, just in May of this year, scientists issued the same warning as Kupni, saying that rain might have invaded the elephant foot room.
The neutron concentration in Room 305, the monitoring point upstairs in Elephant Foot, has doubled in the past 4 years.
This may mean that by the end of 2021, the elephant's feet may re-burn and cause another explosion.
The principle behind this is probably like this.
The three roles of water
Water has three roles in nuclear reactors.
First, when coolant is used, nuclear reaction will release a lot of energy, and water can quickly circulate to take away this energy; second, water happens to become With water vapor, turbine can be driven to generate electricity; everyone should understand these two functions well.
But in the reactor, water actually has a third very important role, which is to be used as a moderator.
How does water slow down the reaction as a moderator?
Nuclear fuel uranium will release neutrons when it is fissioned. In the theoretical model, these neutrons will bombard other uranium nuclei. After the uranium nucleus is bombarded, it will fission and produce 3 new neutrons. With 3 new neutrons, it can bombard 3 new uranium nuclei and produce 9 more neutrons.
and so on,It will produce a chain reaction and then cause an explosion. If this reaction is controlled, it is a nuclear power plant. If it is out of control, it is an atomic bomb.
However, during actual operation, engineers discovered that these neutrons released by uranium are very fast, up to 20,000 km/s.
is such a high speed. In reality, it is difficult for the uranium nucleus to catch it and let it continue to participate in the chain reaction. Therefore, engineers have to find a way to slow down these neutrons, preferably to ten thousandths of the original speed. one.
What should we do?
At this time, engineers suddenly thought of the hydrogen atom in the water. The mass of a hydrogen atom is 1.078u, and the mass of a neutron is 1.0087u. The masses of these two small balls are just about the same.
Friends who have played billiards must know that the white ball is about the same weight as the colored ball. When the white ball hits the colored ball at high speed, the white ball will immediately slow down and the colored ball will fly out at high speed.
This is actually the principle of decelerating neutrons, which is physically called momentum conservation (Newtonian pendulum). It may be more intuitive from a mathematical point of view that neutrons collide with stationary hydrogen atoms.
After the impact, the mass of the hydrogen atom multiplied by the velocity + the mass of the neutron multiplied by the velocity should = the mass of the neutron before the impact multiplied by the velocity.
It’s just right after a meal. Just hit a hydrogen atom to slow down the neutron to an ideal one ten thousandth.
Therefore, water naturally becomes the best slow-down material.
understands the principle of the moderator, and the problem of resurgence of elephant feet can be solved.
Originally, the elephant’s foot has been cooled for 35 years. The chain reaction in it has become weaker and weaker, and the neutrons released have become less and less. This is because it has left the water without the help of a moderator. The sons flew out at high speed, without stimulating a new chain reaction inside,Produce more neutrons.
However, once water and moist air contact the elephant feet that have been cooled, at this time, the elephant feet have a moderator, which can reactivate the chain reaction that has become very weak.
Once this reaction breaks through the critical state, the nuclear reaction will restart and produce a new explosion...
Originally, engineers have always used gadolinium nitrate to deal with water. Gadolinium nitrate is a solution that can absorb a large number of neutrons.
Once the water bursts with neutrons, it must be calmed down with gadolinium nitrate as soon as possible.
However, the problem now is that the safety dome not only affects the natural evaporation of water, but also occasionally allows rainwater to seep into the sarcophagus from the dome. This will cause the sarcophagus to become more and more humid, and the water will flow down and continue to flow. Go to the place where the elephant's feet are.
The devices that were originally designed to automatically spray gadolinium nitrate can only deal with surface problems, and have no effect on the water that seeps into the ground.
So, Chernobyl is waking up, and this report really adds another worry to the troubled 2021.
A photo I have never seen before
At the end of my collection of elephant foot stories, I found another photo on the Internet that I had never seen before.
The person who posted the photo said that this is a photo taken in 1990, four years after the explosion. The photo belongs to Dr. Bill Zoller from the Department of Chemistry at the University of Washington at .
says on the back of the photo, this is a slide I got from a Russian, it shows the so-called elephant feet, taken by a photographer, but then the Russian told me ,The photographer died of radiation poisoning from .
In other words, the price of this photo is a living life.
The elephant's feet did not die, and the body of Chernobyl was still lying in the huge dome and sarcophagus.
Many people have sacrificed themselves silently here, just like everyone mentioned above and the photographer of this photo, maybe it’s just a little bit of data, they just have to do it Made a huge sacrifice.
and we rarely know their stories.
Well, today’s story will be shared here, thank you all.
Finally, the lady said
It turned out that this is a story of unsung heroes.
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Elephant feet: Chernobyl's remains burned again _p7 549 _p7 _pbr 563_pbr0
