introduce
Nuclear energy is the energy released by nucleus through nuclear reaction, which is a great discovery in human history. Using a small amount of nuclear material can release a great deal of energy. This is one of the most promising future energy sources for mankind, but the use of nuclear energy also has great risks. Nuclear disasters in history are also well known.
The idea of using nuclear energy to fly into space appeared in the early days of human exploration of space. In the eyes of scientists, this seems to be the only way for long-distance space flight. Although the United States was the first country to install a nuclear reactor on a spacecraft, it recognized its danger and did not study it in depth. Obviously, the Soviets were much bolder than the Americans and caused a nuclear accident in 1978, which was condemned by the international community.
begin
In the 1960s, the United States built the first nuclear reactor for spacecraft and the only nuclear reactor launched into space. 1in April, 965, the Americans launched a satellite with a nuclear reactor (using uranium 235 as raw material). The satellite worked for a month and a half. Work stopped because of the failure of the carrier satellite. The satellite is still in orbit and will remain in space for the next 4000 years.
Soviet scientists were not idle, and they also thought of applying nuclear reactors to satellites. They have developed a series of nuclear reactor prototypes, such as BES-5 Buk, which are specially designed and manufactured for the US-A series of satellites (known as RORSAT in the west). The US-A series satellites are part of the space intelligence system, and their main job is to track the movements of American aircraft carriers. The Soviet Union launched 3/kloc-0 such satellites.
The Soviet Union began to develop nuclear devices for spacecraft later than the United States. The first sample "romanescard" was successfully tested in 1964- 1965, but it was only a sample and was not launched into space. The reactor was developed by Kurchatov Institute.
By the end of1960s, the Soviet Union had developed a new type of reactor, which used uranium-235 as fuel, just like American reactors. 1June, 970, this device was first installed on the "Cosmos 367" satellite and sent into space. Cosmos 367 satellite worked for 1 10 minutes, and then the core of the reactor began to melt. The satellite was forced into an abandoned orbit.
Then the Soviet Union made three successful launches. 1April, 973, the accident happened again. Due to the transmitter failure, the launch vehicle failed, the satellite could not enter the orbit, and the reactor crashed into the Pacific Ocean. After several successful launches, the US-A radar reconnaissance system was put into use at 1975.
Later, Soviet experimenters successfully launched four satellites with nuclear reactors again, and launched Cosmos 954 on September 1977+08, which is also the most famous satellite in the whole US-A system. Because it almost caused an accident.
offtrack
Two months after the launch of Cosmos 954, American radar detected that it was out of orbit. 1978 65438+1October, American intelligence agencies realized that the Soviet Union might have lost control of Cosmos 954 satellite, and scientists predicted that it would enter the earth's atmosphere between/kloc-0 and October 23 and 24. At that time, during the Cold War, the Soviet Union kept the details of its satellites secret. The United States suspects that the "Cosmos 954" satellite uses nuclear reactors as its main energy source.
If this is true, the situation is very dangerous. A satellite with a nuclear reactor is out of control and is about to fall to earth. As you can imagine, this is a serious disaster. Unfortunately, this is true! So is there a system on the satellite that can push the reactor to a higher orbit in an emergency and prevent the nuclear device from falling to the earth?
In order to find out the specific situation, the United States directly sought real information from the Soviet Union. Moscow quickly confirmed that the satellite was indeed equipped with a uranium -235 reactor. But Soviet officials ruled out the possibility of a nuclear explosion because the critical mass of uranium in the equipment did not exceed. In addition, Moscow guarantees that the design of the reactor will make it disintegrate and burn when entering the atmosphere. At the same time, the Soviet Union does not deny that due to satellite decompression, radioactive debris may reach the surface of the earth, and slight radioactive pollution may occur in the falling area.
"What if a Soviet satellite with a nuclear reactor enters the earth's atmosphere?" This is a problem that the whole world is facing at the beginning of 1978, and it is impossible to determine the place!
The American authorities believe that the world should be informed that a nuclear reactor is descending from orbit and will soon land on the earth's surface. If this information is released to the whole world, it will inevitably cause global panic. The United States decided to inform several of its allies. Scientists are also urgently calculating the trajectory of the satellite, hoping to determine its falling position as soon as possible. Through calculation, scientists predict that one of the trajectories may fall in the Soviet Union, while the other trajectories are in Canada.
Falling and looking
1978 On the morning of June, the Soviet satellite Cosmos 954 burned in the atmosphere and then crashed in northern Canada. The scattering range of radioactive fuel and debris is expected to be within 654.38+10,000 kilometers. Residents of Yellowknife in northwest Canada became witnesses. Someone saw an object similar to an airplane, streaking across the sky with a burning flame, and dozens of small objects nearby followed it, emitting bright red light. The facility contains 45 kilograms of uranium, and scientists are worried that the area will be polluted.
Canada is vast and sparsely populated, especially in the northern region. Fortunately, radioactive debris fell into an uninhabited area in northern Canada. The authorities urgently need to organize a complex expedition to look for satellite debris in cold and snowy places.
Canadian workers were immediately sent to the scene of the satellite crash. The United States wanted to help, and the Canadian authorities agreed. The United States dispatched five C- 14 1 military transport planes and equipped them with relevant equipment and personnel.
Some military and technical personnel first arrived in Neve, Ye Luo. Residents of this quiet northern city were shocked to see people wearing yellow protective clothing walking around and measuring radiation values. Experts have determined that the area to be investigated and searched for debris is 40,000 square kilometers.
First of all, the area needs to be inspected from the plane, which is equipped with radiation detection equipment. If the device shows an abnormality in a box, check it in more detail from the helicopter.
The first fragment of the satellite was not discovered by the military, but by tourists who set up winter camps here. They took a dog for a walk outside and saw a metal object that looked like antlers. One of the tourists stepped forward, picked it up and returned to the camp. They soon learned the news of the satellite crash, because they asked by radio why the plane flew back and forth frequently in this area. After that, tourists from the winter camp reported their findings to the staff of the nearest weather station.
The search team considered how to get close to the wreckage. If the wreckage is active, hundreds of roentgens can be emitted every hour (the lethal dose is about 600 roentgens). In fact, the original radiation range is 10- 100 roentgen per hour.
65438+1October 3 1 day, four paratroopers were sent to the camp. They stayed in the camp for a while, mainly watching the scene and feeding the dogs that couldn't walk.
Other search teams continue to work. In winter in northern Canada, the days are short. It took about 2 hours to fly to the wreckage, and the team members braved the cold wind of MINUS 40 degrees to deal with the wreckage. One of the search teams far away from the main scene, for some reason, the helicopter couldn't start, so they had to spend the night in the tent. This experience made scientists so unforgettable because it was too cold.
On February 10, a large number of moderate radiation sources were found on the ice surface of Danu Lake, the second largest lake in Canada. The search team found many objects ranging from microscopic to the size of corn kernels. Laboratory analysis shows that these particles come from the reactor core. Scientists probably know what happens at the core of a nuclear reactor: it burns in the atmosphere, but it is not completely burned out. The unburned part was blown away by the wind, covering an area of over 80,000 square kilometers. The specific infection area will not be determined until the end of February.
The search operation has a new task. How to clean up such a vast microscopic radioactive particle field? The distance between them may reach hundreds of meters. The scene was divided into several areas, and helicopters equipped with special equipment capable of capturing tiny radiation began to fly at low altitude. Experts sorted out the data recorded by helicopters in groups, and the detected particles were collected in plastic bags with snow. The work lasted for several weeks.
Another issue is also very important: communication with North American aborigines. At the beginning of the search operation, hundreds of Inuit gathered to ask why a large number of troops and equipment interfered with their normal life. There are no such phrases as "satellite" or "radiation" in the language of the Inuit people, so it takes creativity and imagination to communicate with them. Inuit asked the military, what effect will radiation have on people and animals? Finally, they accepted all the explanations and performed their traditional dance for the search team.
The search was code-named "Dawn" and about 120 American scientists participated. It was not until the end of March that they went home one after another. The "Morning Light" operation lasted 84 days and 66 kilograms of debris were found. All fragments are radioactive to some extent, except a large fragment weighing18kg.
The editor-in-chief of the local newspaper once joked that the Soviets contributed more to the local economy in a few days than the Canadian government did in a year!
But for the government, the economic effect is negative, because the cost of action is high. It's almost time to settle accounts with the Soviet Union. We don't know how much it will cost. The Canadian authorities charged the Soviet Union $665.438 billion. 1981April, the Soviet union agreed to pay half of this sum.
be picky
Although there were no casualties, the incident led to a serious scandal. It is worth mentioning that the nuclear-powered spacecraft in the United States also fell. For example, many well-known Apollo 13 accidents, a spaceship carrying 3.9 kilograms of plutonium 238 fell into the ocean. Isotopes will be active for thousands of years, but radiation will not leak into the environment because of the strong shell.
But the situation of the Soviet "Cosmos 954" satellite may be very different. This is a nuclear reactor in operation, which crashed on the territory of another sovereign country. At that time, the United States and the Soviet Union were in a state of cold war. Therefore, the war of words about this incident is also fierce. The Soviet Union insisted at the UN General Assembly that the accident was not serious. Some countries require spacefaring countries to take more measures to ensure the safety of such activities.
Follow-up and prohibition
After the incident, the Soviet Union temporarily stopped launching satellites with nuclear reactors, and the security system was also improved. In case of emergency, satellites can be manually put into other abandoned orbits, and a system for injecting fuel elements from reactor containers is added, which ensures the combustion of harmful substances and debris in the atmosphere.
198 1 year, the Soviet union resumed the launch of nuclear reactor satellites. 1982, Cosmos 1402 was successfully launched, but its fate was the same as Cosmos 954. At the beginning of 1983, it crashed out of control and fell into the sea this time.
Through tests, scientists found that the crash of the "Cosmos 1402" satellite caused rainfall in Arizona. 1984, air samples collected in a coverage area of about 30 kilometers showed that about 45 kilograms of uranium-235 were injected into the atmosphere from the "Cosmos 1402" satellite.
1988, the international community demanded to stop using any nuclear materials in space, because the technical safety of this device is too low. The United Nations explicitly prohibits such activities. Since then, no country has launched nuclear materials into space.