Some say that there are millions of tons of nuclear waste in the world and that they will never be safely buried, in connection with which Greenpeace blocks the railways along which nuclear materials are transported, and demands to curtail the entire nuclear industry overnight. Others argue that real nuclear waste from nuclear power plants around the world is placed in a cube with a side of ten meters. How to understand who is right and who is wrong? And why is what for some “waste” is viewed by others as a valuable investment in the future? Let's try to figure it out.
How much nuclear waste is on the planet today
Nuclear reactors consume surprisingly little fuel: a gigawatt reactor produces only about 30 tons of spent nuclear fuel (SNF) per year. Therefore, over the entire period of operation of nuclear reactors in earth history, they generated only 370 thousand tons of spent fuel, and 120 thousand of these tons have already been reprocessed.
Nuclear power plant fuel in almost all cases is UO2, uranium dioxide, whose density is 10.97 tons per cubic meter. That is, the total volume of spent, but still unprocessed nuclear fuel is less than 23 thousand cubic meters. Even together with the shell, all this will fit into a cube with a side of 29 meters. It is clear that not all of the reprocessed spent nuclear fuel has disappeared - some have gone to storage again. In any case: all the spent nuclear fuel in the world in the entire history of nuclear power is placed in a cube with a side of 30 meters.
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This figure is useful to keep in mind whenever you hear about the "unsolvable problem of nuclear waste disposal." Even if the spent nuclear fuel were really waste - and below we will show that this is not at all the case - its volume is very small. Especially if we compare it with the volume of waste in other energy sectors.
For example, coal energy in Russia alone has accumulated more than 1.5 billion tons of hydrated ash and slag mixture, and its mountains occupy 28 thousand hectares (280 square kilometers) in our country. Moreover, they are often located close to the centers of cities such as Novosibirsk, Kemerovo, Chelyabinsk, Irkutsk, Krasnoyarsk, Novokuznetsk, Ulan-Ude: coal-fired thermal power plants were built for a long time, and the cities gradually surrounded them on all sides. Anyone who has been near such an ash dump in a decent wind knows: being on the leeward side, without a gas mask, it is better not to breathe (and not open your eyes again), but try to run out somewhere where the wind drift does not go.
The huge numbers in the paragraph above are actually modest. In the United States, almost ten times more energy is generated from coal than in Russia, and in China, tens of times more. In these countries, the volumes of unburned coal fuel are much higher, as well as the negative effects from it on human health and the environment.
By the way, it is coal power engineering that is the main source of uranium-thorium pollution of the environment. The "world average" ton of coal contains seven grams of uranium and thorium (roughly equal in proportion to both). The world burns eight billion tons of coal per year. It is easy to see that thermal power plants provide the planet with 55 thousand tons of uranium and thorium annually. In all the spent nuclear fuel in the entire history of mankind, uranium is several times less than in what coal energy throws into the air in just ten years.
With the big difference that uranium from reactors in sealed containers goes to special surface storage facilities, but from billions of tons of burnt coal, it goes straight into the air. Fifteen kilograms of which each of us passes through our lungs every day - that is, five tons per year. Therefore, if you live next to a coal-fired power plant, then with an extremely high probability in your body there is quite an increased content of both uranium and thorium - and it will become even more.
Breeder reactor: why spent nuclear fuel is the main energy reserve of countries
However, in reality, the actual volume of nuclear waste is not equal to the volume of spent nuclear fuel. As noted by the Law on the Use of Atomic Energy (No. 170-FZ), nuclear materials and radioactive substances are considered waste, the further use of which is not envisaged. But, as we have already noted, 97% of the spent nuclear fuel in the reactor is uranium and plutonium, that is, what can be used to make new nuclear fuel. A kilogram of either of these two metals, when fully utilized, gives eight million kilowatt-hours of electricity (with an NPP efficiency of about 33%).
Complete combustion is impossible in one fuel cycle: once the fuel passed through the reactor, it loses a few percent of the initial content of the fissile isotope. A kilogram of uranium that has passed through the reactor once will generate only 620,000 kilowatt-hours, not eight million.
That is why Rosatom is aiming at recycling - the repeated passing of spent fuel through nuclear power plants. Moreover, in all cycles, the volume of the spent fuel mass will decrease somewhat, since with each new cycle, part of its mass is converted into energy.
As part of such recycling, each ton of spent nuclear fuel will generate eight billion kilowatt-hours of electricity. 12 huge wind turbines with a capacity of eight megawatts and a height of 200 meters each have been producing the same number over 25 years of operation. This amount of electricity is consumed by an average Russian city with a population of one million.
In total, 23 thousand tons of spent nuclear fuel have been accumulated in Russia. A simple arithmetic operation shows that ~ 180 trillion kilowatt-hours can be obtained from them - and this is more electricity than our country has consumed in its entire history. Today, it consumes a trillion kilowatt-hours a year, and if this level did not grow, spent nuclear fuel could provide 180 years of such consumption.
All this shows that it is seriously impossible to call spent nuclear fuel "waste" - as is sometimes done in the media. Just as it is impossible to take seriously the proposals for his "eternal" burial under the ground.
If you sell a ton of gold, you get $ 60 million (six billion cents) - enough to buy a billion kilowatt-hours at retail (six cents per kilowatt-hour). In other words, from one kilogram of spent nuclear fuel, using recycling, you can get the same amount of electricity as from the sale of eight kilograms of gold. From 23 thousand tons of spent nuclear fuel accumulated in Russia, one can get as many kilowatt-hours as from the sale of 180 thousand tons of gold. And this is more than the gold reserves of all countries of the world combined. Who in their right mind would decide to bury such a thing underground?
And in Russia, since 2018, they have been producing uranium-plutonium MOX fuel based on exactly those isotopes that are contained in such a once already spent material. And in the BN-800 reactor, MOX assemblies are used to generate electricity: that is, the process of converting the accumulated spent nuclear fuel into real energy has already been launched.
Today, the overwhelming majority of reactors in the world are based on slow neutrons, and they cannot be used to “multiply” nuclear fuel using spent nuclear fuel. At first glance, the mass construction of breeder reactors of the BN-800 type is still a matter of the distant future. However, this is not quite true.
The thing is that, in addition to purely economic considerations, there are also environmental ones. There are no fast reactors in France today, so there they burn fuel on reactors with slow neutrons. The efficiency of this process is not so high: only 40-50% of the spent fuel can be converted into new fuel. But this does not stop the French: other European countries pay them extra for the disposal of their fuel, which makes the process profitable.
It is obvious that the one who will be the first to deploy inexpensive fast reactors (such as the BN-1200 planned by Rosatom, the cost of which is planned to be equal to the price of a slow reactor, such as VVER), will receive a huge advantage. Its reactor will turn into fuel twice as much of the spent nuclear fuel, that is, it will be able to halve its volume and simultaneously obtain a huge amount of energy.
So far, this process has been solidly hampered by the fact that the cumulative GDP growth in Russia has been close to zero over the past ten years, which is why there is not so much demand for new power plants. However, we can say with confidence: in the future, there is no way to get away from recycled fuel.
In this regard, the Russian spent fuel stored under the mountain in Zheleznogorsk should be assessed as the main - both energetically and even economically - the country's reserve. There are thousands of tons of potential usefulness comparable to gold of the same weight.
Reactor-afterburner in mountain halls: the second stage of the recycling scheme
As we found out, the question "how much nuclear waste is there in the world" is much more complicated than it seems. From the above, we learned that 97% of the spent fuel can be used. It is tempting to calculate the volume of nuclear waste from reactors by simply multiplying 250 thousand tons of SNF by the remaining 3% (0.03) - this is exactly the fraction of that part of the spent fuel that cannot be used in BN-800 reactors. The resulting figure of 7.5 thousand tons for the whole world seems small. All this will fit into a cube less than ten meters on a side. But, in fact, this estimate of the volume of nuclear waste is greatly overestimated.
It's all about the composition of these three percent. They are formed during the decay of uranium-235 in an ordinary slow-neutron reactor and consist of almost half of the periodic table. But most of all there is zirconium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, iodine, xenon, cesium, barium, lanthanum, cerium and neodymium.
Most of these isotopes do not pose a serious radiation hazard and can be used in industry. Fortunately, rhodium, palladium, silver with neodymium are not the cheapest metals, the consumption of which has been growing rapidly over the past decades. By the way, there are already methods for their extraction during the reprocessing of spent fuel.
Other decay products of uranium are highly radioactive, but that is why they are valuable. For example, technetium, cesium and radioactive iodine are widely used in nuclear medicine, an industry that has experienced a steadily growing demand for fissile materials over the past twenty years. Strontium and a number of other isotopes are used to produce radioisotope energy sources: it is they that power pacemakers, buoys, unattended beacons and a number of spacecraft.
There is also a third type of fission products, the so-called minor actinides: neptunium-237, americium-Am-241 and 243, curium-242, 244 and 245. These materials have a short lifespan, but therefore they divide at such a rate that in direct sense of the word glow in the dark (reddish or purple light). It would be nice to use them to generate energy, but, alas, their concentration in the fuel element is too low for such a trick. And even if they are removed from there, such fuel will quickly disintegrate, and it gets too hot to make an ordinary fuel element out of it.
Rosatom already knows how to remove uranium and plutonium from spent fuel, but until recently it was not clear what to do with minor actinides.
However, in recent years, technology has been developed that can close this issue. The key role here is played by a substance with the name, which is difficult to pronounce from the first time, lithium tetrafluoroberyllate, which Rosatom prefers to call the FLiBe salt.
This compound has serious advantages, giving it the ability to be an excellent coolant for nuclear reactors using fast neutrons, and even the ability to use minor actinides mentioned above in such reactors. The fact is that fluorine, lithium-7 and beryllium do not absorb neutrons, do not slow them down - unlike such a coolant as water. In addition, lithium-beryllium salt melts at plus 459 ° C, and boils only at plus 1430 ° C. This is extremely important for the efficiency of the reactor: the more the coolant is heated, the higher the efficiency according to the Carnot cycle. In a typical modern reactor (for example, a VVER), water is cooled, which is not heated above + 322 ° C (otherwise it becomes difficult to use).
And to obtain acceptable economic parameters, a water reactor holds water under a pressure of 160 atmospheres, which requires an extremely durable reactor vessel that costs a lot of money. The salt of beryllium and lithium is so heat-intensive that the pressure in the reactor with its use is atmospheric - and there is no need for a heavy-duty body.
It must be said that not only lithium-beryllium salt can be heated very strongly: sodium boils almost at plus 900 ° C, and in BN-800 it is heated to about plus 550 ° C. Therefore, its efficiency is close to 40%, while for VVER-1200 it is not higher than 35%. For the same reason, the pressure in the BN-800 primary circuit is atmospheric. But lithium-beryllium salt has advantages over sodium as well.
First, its heat capacity is four times higher than that of sodium (that is, it needs less in volume). Secondly, it does not burn when it comes into contact with air, but sodium burns - and that is why France and Japan today do not have such reactors (there were fires on sodium fast reactors in both countries). Fluorides are generally extremely difficult to oxidize, so the FLiBe salt is nearly impossible to ignite (and this is a noticeable advantage).
Lithium tetrafluorberyllate has another important feature: uranium, plutonium, and minor actinides dissolve in this salt. Due to this, it is possible to make a reactor without fuel elements, where tetrafluorides of plutonium and minor actinides will be dissolved in lithium and beryllium fluorides. When they disintegrate, the salt pool will heat up, heat the second circuit, and that, in turn, will already generate steam, which will rotate the turbine and generate electricity.
Since the active zone here is completely liquid, then as neptunium, americium and curium decay, it is possible to gradually remove from there the plutonium-238 formed during their decay and add more and more portions of minor actinides. By the way, plutonium-238 is also not a waste, but a very valuable source of energy for space probes and rovers. It is on Russian plutonium-238 on Mars that Curiosity operates.
An experimental reactor of this kind with a capacity of 10 megawatts is planned to be built at the Mining and Chemical Combine of Rosatom in Zheleznogorsk. It is not called "mountain" by chance: it was cut down in the rock under a natural mountain so that it could withstand an atomic strike. The LB-120 reactor once worked there (LB - according to the initials of Lavrenty Beria, the head of the atomic project in the year the enterprise was founded).
After the shutdown of the last reactor for the production of weapons-grade plutonium there, the foothills of the plant are empty. But this is unlikely to last long: a demonstration afterburner reactor will be built there, and it is also planned to create an industrial, gigawatt afterburner there, the low-grade heat from which will be able to warm the city of Zheleznogorsk.
If its trial operation goes as planned, in ten years the plant plans to build a larger reactor-afterburner of minor actinides - 1000 megawatts, at the level of VVER-1000 in terms of electrical power.
In order to efficiently extract lanthanides and other elements from the reactor "bath", Rosatom is developing a technology for the three-stage extraction of components from the gradually replaced fuel of such an afterburner reactor. To do this, liquid bismuth will be introduced into it, and then, into bismuth - metallic lithium, which easily reduces the necessary elements from oxides, which will allow them to be obtained in pure form.
In one of the stages, residual plutonium and minor actinides will be extracted (although they burn out in the reactor, but not 100%), and in the other, lanthanides will also be extracted. Unburned plutonium and actinides will then be reintroduced into the reactor bath, becoming the "second round" fuel.
As a result of the operation of the afterburner, the minor actinides are mainly relatively short-lived isotopes of cesium, strontium, zirconium and molybdenum. Even if the first and second are not useful in radioisotope "batteries" - their half-life takes only 30 to 50 years. That is, after 500 years, the activity of the "afterburner" waste will fall to the level of natural uranium - and they will become practically harmless.
Rosatom is aiming at this: so that products with the same radioactivity that ores extracted from the ground at the beginning of the nuclear fuel cycle had to be buried in the ground.
When using 97% of spent fuel in fast reactors of the BN-800 type and afterburning the remaining 3% in an afterburner like the experimental one currently under construction in Zheleznogorsk, the total volume of waste in the spent nuclear fuel will be much less than 1% of its original mass. In other words, out of 250 thousand tons of unrecycled spent fuel to date, less than 2.5 thousand tons of waste will be obtained. In terms of volume, it is hundreds of cubic meters. And out of 23 thousand tons of spent nuclear fuel accumulated in Russia - about 230 tons, less than 25 cubic meters.
All this shows how little waste actually comes out of the gates of the nuclear power plant. For more than 60 years of operation of the nuclear power industry, it has been possible to accumulate only 2,500 tons of what, in fact, cannot be processed. Yes, this one hundred cubic meters of waste (for the whole world) will have to be stored in containers for 500 years before it can be buried in the ground. And still, in terms of mass, it is very small: when one large windmill is dismantled, which has worked out its life, hundreds of tons of waste are generated, which today, as a rule, are simply buried in a landfill. For a trillion kilowatt-hours of production, wind turbines only produce spent fiberglass blades at least 150 thousand tons - but this does not prevent them from being considered an environmentally friendly source of energy.
And what does Greenpeace then call "millions of tons of nuclear waste"?
All these figures are perplexing. Periodically, representatives of Greenpeace claim that there are millions of tons of nuclear waste in the world, and in Russia alone there are more than a million tons. But what millions of tons are we talking about if atomic reactors in their entire history and half a million tons of fuel have not been used? And in a quarter of a million of unprocessed initial fuel of real waste - 1%?
With Greenpeace's numbers, everything is not so difficult: the main thing is not what they count, but who counts. Greenpeace employees cannot say "nuclear energy leaves less waste per kilowatt-hour than wind turbines" - even if this is true. Therefore, to make nuclear power plants look worse in the eyes of public opinion, greens write in nuclear waste … uranium hexafluoride.
The organization even says that Russia also imports such "nuclear waste" from Germany. And they say: "European producers are interested in Russian contracts not so much for the additional enrichment of DUHF, but for its disposal [in Russia]." True, there is a nuance: in Russia, nuclear waste is not buried at all, even its own. Moreover, this applies to uranium hexafluoride - a compound, both components of which (both fluorine and uranium) in our country are able to use fully.
This is a substance that is used to enrich natural uranium - that is, when the concentration of uranium-235 in it increases to several percent instead of natural 0.7%. During enrichment, a little fuel is obtained - about 10% of all mined uranium goes there - and depleted "tailings", dumps of almost "empty" (for uranium-235) rock.
As you might guess from the word "empty", the radioactivity of such a substance is lower than that of the same uranium hexafluoride before the start of enrichment. That is, this substance is much less radiation hazardous than uranium in nature. The activity of uranium hexafluoride before enrichment is only 14 thousand becquerels per gram, and after that it is much less. For comparison, it may be recalled that a gram of radium has an activity of about 37 billion becquerels.
During the radiation incident in Goiânia, Brazil, where a persistent but insufficiently educated robber uncovered a radiotherapy device, a source with an activity of 74 trillion becquerels killed four people - and 40,000 tons of uranium hexafluoride has the same radioactivity. That is, the radioactivity from it is so low that a person can safely sit on a barrel with it.
But the most important thing in this substance is different: two-thirds of it by weight is uranium-238. Which, as we noted above, when passed through "fast" nuclear reactors and repeated recycling of their fuel, gives eight million kilowatt-hours per kilogram - much more than can be bought for gold of the same mass.
In this regard, it is worth taking a different look at the story of the import of uranium hexafluoride to Russia from Germany, which Greenpeace does not like so much. Its essence is that Germany does not have its own developed technologies for the re-enrichment of uranium, but in Russia they do: here uranium enrichment has historically been and remains at the forefront of the technological capabilities of mankind.
Therefore, the Germans decided to take their uranium hexafluoride to us, where it will be re-enriched, the enriched in uranium-235 (small) part will be brought back to Germany, and the "tails" depleted in uranium-235 will be left with us.
What does Rosatom have from this? To begin with, a series of reactions at the W-EKhZ installation (Zelenogorsk) from this hexafluoride can be used to obtain hydrofluoric acid, which is not the cheapest material. In a more distant - and much more important - prospect, uranium-238 from the remaining "tailings" can be used as fuel. Beloyarsk NPP is already doing this: about 10% of the fuel in the BN-800 reactor is MOX fuel. In addition to plutonium, the same oxide of depleted uranium-238 is used for its production. And this oxide is obtained precisely from uranium hexafluoride, "tailings". By 2023, the share of such fuel in BN-800 should reach 100 percent.
For 2020, one hundred thousand tons of uranium hexafluoride has already been processed in Zelenogorsk, and the process continues. Only in 2011-2017, 49 thousand tons of hydrofluoric acid and hydrogen fluoride were obtained from it and sent to the chemical industry, and the uranium itself was tied in the form of uranium oxide, U3O8.
According to Greenpeace, Russia imported from Germany more than 140 thousand tons of uranium hexafluoride, some of which went back, and some remained. The rest contains 80 thousand tons of uranium itself. That is, when it is passed through a breeder reactor, these "waste" can give 640 trillion kilowatt-hours. Which is 25 times the annual electricity consumption of the entire planet.
But Moscow should not be accused of treachery. Yes, in fact, Rosatom received money from the Europeans for being able to keep the raw materials for a huge amount of nuclear fuel. But he did not deceive anyone: our European partners simply do not have technologies that would make it possible to enrich uranium hexafluoride as efficiently as in Russia, and even more so to use uranium from depleted tailings in "fast" nuclear reactors.
In addition, Rosatom does not import tailings because it wants to snatch more free raw materials for future fuel. Russia itself has a million tons of uranium hexafluoride. They contain more than 660 thousand tons of uranium-238, that is, potentially five quadrillion kilowatt-hours can be generated from these "waste".
It turns out to be a paradoxical situation: Rosatom has been consistently, for many years in a row, reprocessing "tails" from uranium enrichment. And, according to logic, the greens should support this process with both hands - especially since in Germany they do not know how to process uranium hexafluoride. Moreover, they do not know how to use depleted uranium as fuel, as at the Beloyarsk NPP.
But instead of supporting, Greenpeace … criticizes those who process nuclear materials. Why is recycling of plastics good and recycling of nuclear materials evil? Why try to stop them from being recycled? Unfortunately, the Greens themselves have not yet formulated the answer to all these questions.
"Waste", which is more valuable than the gold reserve
Let's summarize. In Russia, almost 800 thousand tons of uranium is stored in the form of "empty" dumps (from uranium-235, but not from uranium-238). Another 23 thousand tons of raw materials for future fuel are stored in the form of spent nuclear fuel. The total amount of electrical energy that can be extracted from them is over 6.4 quadrillion kilowatt-hours.
And if you add up all the reserves of Russian coal, gas and oil, it turns out that from them (with a generous efficiency of 60%), you can get 1, 3 quadrillion kilowatt-hours of electricity. Of these, coal accounts for less than 0.84 quadrillion, and gas - about 0.23 quadrillion kilowatt-hours. Another 0.2 quadrillion can be obtained from all Russian oil. Conclusion: nuclear "waste" stored in Russia, which is not waste at all, can give it five times more energy than all of its fossil fuels put together.
Only oil, gas and coal have to be somehow extracted from the earth. And in the case of coal, this is most often done in huge open pits, with large and unpleasant environmental consequences. Suffice it to recall that 600 thousand tons of explosives per year are spent on coal mining and in Kuzbass alone - forty Hiroshima in TNT equivalent. In the video below, it is easy to see what these 600 kilotons per year sometimes lead to (be careful, loud sound):
Landslide near the Zarechny open-cut mine in Kuzbass. April 2015
But "nuclear waste", which, in fact, is more likely a gold reserve, has already been mined - and to use their energy does not need to cause any damage to nature. It is enough to take it from storage sites. Moreover, as soon as the nuclear industry begins to use fast reactors in significant quantities, the need for the production of new uranium hexafluoride will gradually disappear by itself: there will be no need to enrich natural uranium ores, because you can simply use what has long been taken out of the earth.
At this point, one might wonder why Greenpeace is trying to call waste materials that are potentially more important than any other material reserves of our country. But we will not do this, because in a separate text "The Price of Fear" we have already described why the greens are so seriously mistaken about nuclear energy, as well as how many lives humanity has paid for these delusions.
Therefore, let's dwell on something else. The figures show that for the nuclear industry, recycling and respect for nature are a natural and most beneficial way of development. The accumulated raw materials for the production of new fuel are quite enough to supply nuclear power plants for thousands of years ahead.
A fundamentally new afterburner reactor in Zheleznogorsk will allow avoiding the disposal of hazardous materials with increased radiation activity and returning to nature the same number of becquerels that people once took from it in uranium mines. Moreover, all this, taking into account the promising designs of the BN-1200 type and reactors on lithium and beryllium salts, will be quite justified economically. Perhaps, from a purely technical point of view, the nuclear power industry has really good prospects.