Until we learn how to get energyfrom fusion reactions, the most effective and economical way of its extraction will be nuclear power plants. Only they can provide a huge amount of energy with minimal fuel consumption. The problem is different. All this fuel, after becoming the category of "spent nuclear fuel" (SNF), becomes a burden on our planet. It must be put somewhere and you have to pay for progress. As they say, the entrance is the ruble, the output is two. But how can you cope with it so that this fuel does not harm the planet and its inhabitants? It turns out that there are several very effective ways besides burial. Let's see what the “exhaust” of a nuclear power plant turns into.
- 1 What are the types of radioactive waste
- 2 What to do with radioactive waste
- 3 How nuclear industry waste is stored
- 4 How to process nuclear fuel
- 5 Where is nuclear fuel disposed of?
- 6 Why do they bury nuclear fuel rather than destroy it?
- 7 Nuclear Fuel Alternative
What are the types of radioactive waste
First of all, you need to understand thatRadioactive waste is generated not only from nuclear power plants, but also from other areas of human activity. For example, from research and laboratory work with radioactive isotopes, radiation therapy of cancer patients and from radioisotope thermoelectric generators (RTGs), which are used in hard-to-reach places for energy. Although, recently they have been used mainly only at space stations.
There is another very large sourceradioactive waste, namely the military industry, and especially the legacy of the Cold War. It is rockets, bombs and submarines of that time that are still being processed and pose a threat of infection.
In general, radioactive waste per year is producedhundreds of thousands of tons, but not only due to the fact that so much fuel is produced, but due to the fact that according to the requirements of the IAEA (International Atomic Energy Agency), radioactive waste is recognized as any production waste that has an output level above the standard level. So here comes equipment, machinery, cranes, overalls, appliances, even stationery and entire cars. According to the standards at the enterprises, everything is constantly checked, and before writing off, a control measurement is made and the decision is made to simply discard or dispose of it.
By the way, I hasten to please you. Contrary to popular belief, that everything is brought to Russia for a penny and buried in the Far East, this is not so. Moreover, since 2011, a law has been in force that prohibits the transfer of nuclear waste across the border (in both directions) with the exception of the return of fuel waste that was produced in Russia or the USSR. This ensures compliance with the requirements of contracts for the supply of fuel and equipment.
How does a nuclear power plant work? Are nuclear plants dangerous?
Naturally, in our country there should bethe normal number of enterprises that deal with the further fate of radioactive waste and they are, for example, the well-known software "Mayak". It is interesting that, contrary to popular belief, waste is not only disposed of, but also found in other, often useful applications.
What to do with radioactive waste
There are several ways to solve the furtherthe problem of radioactive waste. The main ones are processing, storage and disposal. Sometimes they resort to combined methods that can be used in any combination, if this allows you to achieve the correct result.
First of all, before starting work, waste is collected from enterprises that work with appropriate materials.
According to current legislation, workwith radioactive elements and their waste can only enterprises that have the appropriate license. The operation of enterprises is limited by strict rules and the principle of “what is not prohibited, what is allowed” does not work. On the contrary, “what is not allowed is forbidden”.
Waste is transported to plants in specialcontainers, which can be steel, lead, reinforced concrete, enriched with boron polyethylene and others. All waste is transported with strict observance of safety standards, and large consignments even accompanied by convoys.
How nuclear industry waste is stored
For some wastes, a decision is made to store them. This happens when the processing is very expensive or complicated, as well as when all other methods are no longer suitable.
An example of what is easier to bury thanrecycle, are the nuclear submarines of the Cold War. In the midst of the arms race in the USSR, there were more than two and a half hundred, and now about five times less. The remaining two hundred boats, like floats, were in jokes until the time came to turn them over. Yes of this, three compartments (reactor and two neighboring) were cut out of them and sent for storage in special packages. The rest was processed normally.
Such storage is carried out on a rocky base. To do this, they even removed part of the hill so that they did not stand on the ground, through which groundwater pollution could occur, which would carry all the elements even further.
Such storage is completely safe, but looksso-so. And simply, it's better to hide this waste out of sight. To do this, approximately the same storage facilities are made, but bunkers are built around them and all this is sprinkled with earth so that they do not at all give themselves out. This is done only with not very hazardous waste, which can still be recycled after some time.
Sometimes for temporary storage are doneartificial canned concrete boxes, which are also called wet, but this is also a temporary measure. To do this, they still have thick concrete walls, but they are not able to safely store waste within themselves for hundreds and thousands of years. For this, it is not necessary to build storage facilities, but full-fledged burial grounds. We will talk about this a little lower.
You just need to understand that some waste hashigh radioactivity, and some not. In addition, the half-life of one isotope is tens of years, such as tritium, and some, billions, for example, of some uranium isotopes.
How to process nuclear fuel
For reprocessing spent nuclear fuel andother wastes use a completely different approach depending on what is specifically recycled. For example, part of the solid waste is burned in special furnaces with a sophisticated air filtration system. The ash and ash obtained at the outlet are buried for a long time in burial grounds. So waste takes up significantly less space and does less harm.
If the waste is liquid, it is concentrated byevaporation. Then they are also sent for long-term storage, if nothing else can be done with them and they carry a great danger. To do this, they are packed in thick barrels of 100 or 200 liters of lead or steel.
Why do you think scientists are concerned about the atomic problem?
However, most of the waste can beRecycled for future use, for example, in medicine or research. Such wastes are those that contain uranium-235, uranium-238, plutonium and a number of other isotopes. Thus, up to 97 percent of nuclear fuel can be reprocessed. That is, as we see, the fuel itself is not so scary for the environment. It is very well reused. A completely different matter is the waste that cannot be recycled and cannot (and there is nothing) to store. This is where the headache really begins.
Where is nuclear fuel disposed of?
You must understand that the waste of the nuclear industry,which have high radioactivity and are no longer needed by anyone, must be disposed of so that they reliably lie in their "house" for thousands and even tens of thousands of years. Scientists have long come to the conclusion that the most reliable places for this are rocks at great depths.
Generally storage in rock formations is verypromising and provides the very tens of thousands of years of reliable conservation. The Earth itself helps in this, but what within our world can be more eternal than its firmament? Therefore, rocks are needed. For example, in the United States there is an active debate over the construction of the Yucca Mountain burial ground in the Nevada desert. It should go hundreds of meters into a volcanic mountain range. Even Sweden, one of the most environmentally friendly countries, is considering burial options inside rocky foundations. And since 2015, Finland has been practicing this and continues to expand the usable storage capacity. It turns out that there is nothing wrong with that? It turns out so.
Rock burials at a depth of 400meters and more are so reliable that they can withstand even a meteorite that will destroy life on Earth. Then it will begin to evolve again, and the waste will still be securely hidden.
As temporary burial sites in emergencycases, man-made repositories are used. Thick concrete bases are being prepared for them. Radioactive waste is placed in these pools, after which several more layers of concrete are poured on top. Sometimes, pouring with molten borosilicate glass is also used as an additional safety measure. So conservation will be even more reliable, but still this method is used more as a last resort, since rocks are a much more permanent thing. They were a million years before us, they will be a million years after us, and we can only guess how concrete will behave after 100 years. Sorry, predict.
For example, there are such burial grounds in Chernobyl, whereit’s just no sense to take out tons of land and other garbage. In order for pollution to be even a little less, especially hazardous waste is collected in such landfills, equipped directly on site.
An important point in the construction of burial groundsis accounting for spent fuel heating. Due to the fact that it is still active, processes taking place at the atomic level lead to heating of the material. This is taken into account and burial grounds have a special heat-dissipating structure. If this is not taken into account, an uncontrolled increase in temperature may end badly
Not so long ago, it’s very hot in our Telegram chatdiscussed the topic of waste disposal in space. In principle, this idea is very good. It is enough to launch containers with waste in the direction of the Sun or in pursuit of the Voyagers and the problem is solved, but the price tag of such work will be just cosmic. Perhaps sometime at a new stage in the development of technology, after about 1000-1500 years, our descendants will be able to find a way to cheaply put them into orbit and then they will send all our garbage from the landfills to hell.
Why do they bury nuclear fuel rather than destroy it?
You need to understand that technology is nowtechnologies in 50-100 years or more are at a completely different level. Based on this, it makes sense now not to engage in expensive deep processing of radioactive waste. It will still not be possible to completely clear them out, but after tens and hundreds of years of industry, rare isotopes may be needed that people of the future can find in the very repositories and burial grounds that we are building now.
There is also the possibility that in the futuretechnologies have reached a new level and what we simply cannot process now will be enough to pour from a bucket (of course, exaggerated) and everything will become normal. So far, scientists are doing everything they can, but burial and recycling are in balance, and not in the desire to process as much waste as possible at any cost.
Nuclear fuel alternative
An excellent alternative to nuclear fuel and nuclearStations in general are thermonuclear reactors. I already talked about them and, if interested, you can read in detail in a separate article on our website.
In a nutshell, this technology wasinvented back in the fifties of the last century. For its implementation, a tokamak (toroidal chamber with magnetic coils) is used. A vacuum is created in it, and instead of air, a mixture of deuterium and tritium is pumped (variants of hydrogen compounds). Under the influence of a magnetic field, the mixture heats up to a plasma state - the fourth state of aggregation of a substance. Its temperature reached 70 million degrees Celsius as early as 70 years ago. In the ITER international tokamak, which is being built in the south of France, the plasma temperature will reach 150 million degrees. The walls of the chamber at such a high temperature do not melt due to the fact that all the plasma is in a suspended state. Almost in a vacuum.
This technology is safe. Even tritium with little radioactivity has a half-life of only 12 years. Such an installation cannot explode even in the case of an emergency, since the pressure inside is much lower than atmospheric pressure, and in case of violation of the conditions, the plasma formation immediately ceases. Even simply shutting off the fuel supply will immediately stop the reaction.
What is Tokamak? Just about a fusion reactor
The best part is that you literally need fuelminimum. So, 80 grams of a mixture of deuterium and tritium, which are very easily obtained from plain water and cost a penny, produce as much energy as 1,000 tons of coal burned.
Unfortunately, so far the technology cannot beimplemented on an industrial scale, but with a favorable scenario, it will take only 10 years. After that, we can get an almost endless source of energy in the form of a small sun on Earth. And most importantly, the price of such energy will be minimal, as well as the risks of receiving it.