Speaking of what changes have occurred in the human body after being irradiated, everyone will surely think of the two most influential nuclear leaks in history, one was the Chernobyl nuclear accident in the former Soviet Union in 1986, and the other was the Fukushima nuclear accident in Japan in 2011.
However, in the history of nuclear leakage, there is another "JCO critical accident in Tokaimura, Japan" that can definitely be recorded in history, although the death toll is only 2 people, the accident process is very typical and two employees have died in pain after more than 2 months of inhuman torture, which is unique in the history of medical treatment in the world!
<h1>Tokaimura JCO critical accident, should not occur low-level accidents</h1>
This is the accident that occurred on September 30, 1999, at the JCO nuclear fuel preparation plant in Tokai village, Naka Prefecture, Ibaraki Prefecture, which is a plant that recovers nuclear fuel from nuclear waste and breeding reactors, and is not complicated from the process point of view, the basic principles are as follows:
The resulting uranium compounds from dissolving nuclear fuel rods or yellowcakes (oxides of uranium) in a breeder reactor in nitric acid are followed by the preparation of uranium hexafluoride and then isotope separation to prepare enriched uranium (e.g., using centrifuges, etc.) to separate uranium-235 and uranium-238).
Therefore, in the JCO nuclear fuel preparation plant, there will be a dissolution tower and sedimentation tank, and the pure uranium content in the sedimentation tank shall not exceed 2.4 kg according to the regulations, which is set because fissile materials such as uranium and plutonium have a critical mass, and the critical mass is formulated for the following reasons:
Fission material has a minimum mass that satisfies the chain reaction fission, the principle is that the neutrons produced by fission hit the next uranium nucleus before flying out of the uranium material, and continue to fission, the resulting 2-3 neutrons continue to hit the minimum mass of the next uranium atom, because the nucleus inside the atom is very small, for the neutron the atom is very empty, so it must be large enough to guarantee hitting the next nucleus before flying out!
For example, the critical mass of uranium-233 (most of the general uranyl nitrate is uranium-235 and uranium-238) is 15 kg, so it is necessary to limit this critical mass, once exceeded, a chain reaction will occur, but this is still different from the chain reaction of the nuclear explosion, but there will also be super strong neutron radiation and gamma rays, which will cause nearby operators to suffer extremely strong radiation!
At 10 o'clock on September 30, 1999, three operators dissolved 2.4 kg of uranium oxide powder in a 10-liter stainless steel drum, then divided into 5 kg barrels, and then introduced into the sedimentation tank with the sampling hole of the funnel, and then stirred, in fact, this is no longer in line with the operating specifications, but as long as it does not exceed the critical mass, it is actually nothing!
But on the first day, they had already poured 26 liters of nitric acid oil solution with a concentration of 18.8% (380gU/L) into the sedimentation tank, and at 10:35, they poured a third barrel of nitric acid solution, at this time the sedimentation tank had exceeded 40 liters, and by concentration, it had exceeded 15 kilograms of pure uranium!
In an instant, a blue light of death burst out of the sedimentation tank (the stainless steel barrel could not prevent the neutron from penetrating at all), the amount of uranium nitrate solution in the sedimentation tank had reached a critical mass, and the fission reaction began, and the neutron and gamma ray alarm bells rang, and the sedimentation tank at this time had become a nuclear reactor exposed to the air, and the operation room had also become a dead zone.
Why is there a critical accident, 16 kg of uranium is far from reaching a critical mass
All three workers were exposed to great radiation, but when the critical reaction occurred, the two workers were about half a meter away from the sedimentation tank, and the person in charge (deputy foreman) was in the next room, and because of the distance, they escaped death!
However, although the Tokai Village Office had been established to establish the Disaster Countermeasure Headquarters, everyone did not know what had happened, and it was not until the Na-24 was detected in the vomit of the three operators that it was speculated that a critical accident might have occurred. But this is close to 16 kg of uranium, although the mass has exceeded the standard safety regulations, but far from the critical state, why is there a critical accident?
After the establishment of the Local Countermeasure Headquarters of the Tokai Research Institute, the nuclear energy experts of the Agency for Science and Technology, the Japan Atomic Power Research Institute, the Japan Nuclear Fuel Development Agency, and the power company discussed and analyzed, the cooling water jacket on the outside of the sedimentation tank played the role of a neutron reflector. Therefore, in a state much smaller than the critical mass, a critical state is reached!
So the JCO organized a death squad to drain the water, and urgently transported the boric acid solution into the sedimentation tank to absorb the neutrons, and the rescue work continued until the morning of October 1, and the reaction gradually stopped.
83 days and 211 days, the most painful process of death in the world
The accident rescue has ended, but the suffering of these three staff members has just begun, in addition to the three staff members on the scene, there are 213 other emergency rescue and workers were irradiated, but the rest of the personnel recovered their health after treatment, and two of the operators radiation is particularly serious, the largest amount of radiation is the closest to the sedimentation tank Ouchi Jiu, reaching 16-23Sv, and the more recent one is Shinobu principle person: 6-10 Sv.
However, when sent to the hospital, there is no abnormality on the surface of the body, except for the fact that Ouchi's right hand is a little abnormal, there is nothing unusual, the lethal dose of neutron radiation is 2 Sv (Seaver, radiation dose unit, generally use milliseifers and micro-Seaver), so all 23 pairs of chromosomes in the human body are completely destroyed by radiation, and cause the body's immune system to completely lose function and most of the cells are not regenerative and decayed!
Simply put, from this point on, ouchi and Shinobi's human life begins to count down, but how long it will be, and what is the process, although the medical staff and experts have the corresponding psychological preparation, but it is still beyond imagination, there is no more painful death process in the world!
A week later, the doctor was horrified to find that their skin was torn off after removing the tape, and it was getting more and more serious, the wound could only be attached to the band-aid, but the band-aid replacement tore off a layer of skin, which was the surface of the body, and the body was shedding of the mucous membrane of the digestive tract, continuous diarrhea, a lot of dehydration, and had to replenish a lot of body fluids.
Both Ouchi and Shinobu have hydropulmonary water, difficulty breathing, need a ventilator, the condition deteriorates rapidly, the skin of the whole body is not intact, bleeding is oozing everywhere, even the skin transplant after skin grafting can not be attached, it looks like a melting living corpse, and the most terrifying thing is that most of the time they are awake.
Because the internal and external mucosa and skin are no longer repaired and grown, every day is a large amount of bleeding, rescue must be a large number of blood transfusions, the heart load far exceeds the normal level, the burden of kidneys and livers exceeds the normal number of times, the final endless bleeding and the failure of various organs, 83 days after the accident, the closest to the sedimentation tank of the Ouchi long rescue ineffective death, 210 days later Shinobi principle people also died. Fortunately, the person in charge in the next room escaped and recovered.
In fact, both of them asked the medical staff to kill themselves when they were awake, but no one agreed, although the doctor's starting point was to try their best to save him, but everyone knew that they were bound to die, and blindly prolonging the painful time, witnessing their own continuous decay every day, why?
More precisely, instead of rescuing two operators who suffered from nuclear radiation, the Japanese medical community wants to record the death process of the human body after being severely exposed to nuclear radiation in real time, and the 83 days of rescue have public details, which is too cruel, a large number of bloody pictures can not be published at all, or even can not be described in too detail, otherwise this article review will not pass at all.
The Japan Broadcasting Corporation (NHK) recorded their rescue process throughout the process, which was compiled into a documentary and a book called "Japanese Nuclear Radiation Death Incident", which interested you can read, of course, you must not overestimate your psychological endurance, otherwise you may have nightmares!
Further reading: About radiation
Many friends have always been far away from radiation, as far as nuclear radiation, as close as mobile phone radiation, but radiation is indispensable in our lives, because the sun transmits heat to the earth is also radiation, all our radio communications are also radiation, and even our body itself is radiating infrared light outward!
The per capita dose of natural radiation worldwide is about 2.4 mSv years, and in China about 2.3 mSv years
In addition to the radiation of neutrons and electrons and atomic nuclei, most of the so-called radiation is the different bands of light, and nature itself has background radiation, so we are all surrounded by radiation all the time, but you don't have to panic at all, because you can't escape, such as carbon-based life, that is, all life on earth, there is carbon-14 in the body, it is radioactive, and it will decay.
As long as the radiation is within the safe range, it is healthy for human beings, and interested parties can check the indicators of radiation.