Generation 3 reactors are called "advanced reactors". Three such reactors are already operating in Japan, and more are under development or construction. There are about twenty different types of reactors of this generation under development. Most of them are “evolutionary” models, developed on the basis of second generation reactors, with changes made based on innovative approaches. According to the World Nuclear Association, Generation 3 is characterized by the following points: A standardized design for each type of reactor allows speeding up the licensing procedure, reducing the cost of fixed assets and the duration of construction work. Simplified and more robust design, making them easier to handle and less susceptible to failures during operation. High availability and longer service life - approximately sixty years. Reducing the possibility of accidents with core melting. Minimal impact on the environment. Deep fuel burnout to reduce fuel consumption and production waste.
Despite the diversity and differences in scenarios for future energy development, there are a number of provisions that are unshakable for making forecasts in this area:
- growth of population and global energy consumption in the world;
- Increasing competition for limited and unevenly distributed fossil fuel resources;
- increasing dependence on the unstable situation in the areas of oil exporting countries;
- increasing environmental restrictions;
- the growing difference in energy consumption between the richest and poorest countries.
Under these conditions, the role of nuclear energy (NE) is increasing as a stabilizing factor in energy and socio-political development.
Despite all its problems, “nuclear” Russia remains a great power both in terms of military power and in terms of economic development (nuclear technology in the Russian economy).
It was the Russian President who spoke at the UN at the Millennium Summit (September 2000) with the initiative to ensure energy stability of development based on nuclear technologies. This initiative turned out to be extremely timely and found support from the world community: four resolutions of the IAEA General Conference and two resolutions of the UN General Assembly welcome the initiative of the Russian President as meeting the aspirations of developing countries and as a way to harmonize relations between industrial countries and developing countries.
The initiative of the President of the Russian Federation is a political action, not a technical project. So this was accepted by the world community and was reflected in the international IAEA project INPRO - on the development of an innovative concept of nuclear power plants and the nuclear fuel cycle (NFC), excluding the use of the most “sensitive” materials and technologies in the global energy sector - “free” plutonium and highly enriched uranium, and opening up fundamentally new prospects for life to the world” (September 2000).
The implementation of the international INPRO project made it possible to unite the efforts of experts from 21 IAEA member countries and develop requirements and criteria for the development of nuclear power plants, nuclear power plants and nuclear fuel cycles.
The emphasis on the content of the president’s proposals as a political initiative made it possible to “healthier” the atmosphere of the IAEA, considered by Western countries as an organization with police functions, orienting the IAEA to the role of a world forum to discuss the place of nuclear energy in the world, and, in particular, for developing countries - in accordance with the initiative president. Moreover, the initiative of the President of the Russian Federation implies the transfer of new innovative nuclear technology of nuclear power plants and nuclear fuel cycles to a new generation of scientists and engineers - as a legacy of our knowledge and experience. The new IAEA program in the field of “knowledge preservation” is focused on preserving knowledge and experience in the most advanced and key for future development (but not in demand today) field of nuclear energy - fast neutron reactors in a closed nuclear fuel cycle.
Preservation and transfer of knowledge to a new generation overlaps with the task of global cooperation in the field of nuclear energy: “West – East” and “North – South”; to transfer knowledge both in time and in space - to new regions (primarily to developing countries, where 4/5 of the planet's population lives and less than 1/25 of nuclear power capacity is used).
This was the reason for putting forward the initiative to create an International Nuclear University (at the initiative of the IAEA, supported by the World Nuclear Association (WNA) and the World Association of Nuclear Operators (WANO)) - a logical development of the initiatives of the President of the Russian Federation.
However, in the practical implementation of the nuclear power development program within the country and in the implementation of our technical projects on the international market, negative trends are becoming more and more clearly evident. The first bell has already sounded: the loss of the tender in Finland, which means for specialists a practical loss of chances for a place in the market not only in Europe, but also (for the same reasons as in Finland) a decrease in the chances of success in the coming decades in China, as well as in other Asian countries. Moreover, in the near future the situation on the international market will become much less favorable due to the following reasons:
- decommissioning of NPP power units to which Rosatom (TVEL Concern) supplies fuel (Ignalina NPP, a number of Kozloduya units, etc.);
- accession to the European Union of Eastern European countries - owners of nuclear power plants with VVER-type reactors;
- the end of supplies of nuclear fuel to the United States under the HEU-LEU contract after 2013;
- commissioning of a plant with centrifuge technology in the USA after 2006;
- creation of transnational corporations in the nuclear sector (concentration of resources, reduction of costs);
- implementation of new competitive nuclear power plant projects developed by the USA (AR-1000,
- HTGR) and other countries (EPR).
In addition, there are a number of internal difficulties complicating the development of the nuclear industry (along with a lack of investment funds):
- decommissioning of nuclear power plants at the end of their service life;
- closure of three industrial reactors in Zheleznogorsk and Seversk;
- reduction of reserves of cheap uranium raw materials accumulated in previous years;
- restrictions on the rights of state unitary enterprises;
- imperfect investment and tariff policies.
Even with the maximum possible use of the concerns’ own funds (in accordance with Russia’s energy strategy), the contribution of nuclear power plants to the country’s energy balance will be very modest, despite the enormous technological and personnel potential of the “nuclear” power.
The situation has worsened significantly recently due to the reform of the Russian nuclear complex and the transformation of the powerful government body Minatom into the Rosatom agency. At the initial stage of the successful development of the nuclear defense and energy complex, the role of the state was decisive in all respects: organizational, financial and scientific, because this complex determined the country's sovereign power and future economy. It is obvious to specialists that the country’s nuclear shield and global nuclear technologies are two sides of a single scientific and technological complex. Without the cost-effective peaceful use of nuclear technology, a “nuclear shield” will either collapse the Russian economy or become a “shield” that does not ensure the complete security of the country.
At the same time, the main mechanism and foundation of Russia's sovereignty - the nuclear complex - turned out to be outside the sphere of direct influence of the head of state - the President of Russia.
As a consequence, the lack of clarity in a real nuclear energy strategy leads to a loss of continuity between generations. Thus, Russia, the most advanced country in the development of fast neutron reactors and in the field of higher nuclear education, currently does not have a national program for preserving nuclear knowledge and experience, just as it does not have a national program for participation in the World Nuclear University.
FURTHER DEVELOPMENT OF NUCLEAR ENERGY
Further effective development of nuclear technologies due to their special “sensitivity” is impossible without close international cooperation. At the same time, it is very important to correctly determine the technological and “market” niche where domestic developments still have priority.
In the world market of traditional nuclear power in the near future there will be further expansion of the European Power Reactor (EPR), which won the tender in Finland, as well as the American AR-1000 and Asian (Korean and Japanese) reactors.
The lack of a completed technical design and uncertainty with the timing of the reference demonstration of the new generation VVER (VVER-1500), as well as the lack of a “standard”, fully completed VVER-1000 project, makes Russia’s position in the foreign market of traditional power units vulnerable. To select a program of action, it is necessary, first of all, to conduct a comparative analysis of the main indicators of the domestic VVER-1000 and VVER-1500 projects with their Western competitors at the time of implementation.
In these conditions, taking into account contractual obligations in China and India, it is necessary to concentrate funds on the completion and demonstration for domestic and foreign markets of a standard competitive VVER-1000 and the implementation of a technical design of VVER-1500 comparable in terms of performance to EPR.
The market (domestic and external) for innovative small nuclear power plants could be potentially favorable for Russia. Vast domestic experience in the development and creation of nuclear power plants for the naval and icebreaker fleet (more than 500 nuclear reactors) and the uniqueness of domestic water-water and liquid metal (Pb-Bi) nuclear power plants nuclear power plants, along with the potentially huge energy market of developing countries, makes this area a priority for domestic and foreign markets. Russia is an ideal testing ground for demonstrating the harmonious development of traditional nuclear power plants (with VVER-1000 units) and innovative developments of small nuclear power plants (electricity, desalination, heating). At the same time, the possibility of leasing supply of a “product” (nuclear power unit, fuel), rather than technology, can be demonstrated, which is one of the possibilities for solving the “non-proliferation” problem.
Decisive here may be the creation of small transportable nuclear power plants (for example, floating) with a continuous operation period (without overloading throughout the entire operation period) of ~ 10–20 years.
The role of fast neutron reactors for the future development of nuclear power as the basis for solving the problem of fuel supply using both uranium-plutonium and thorium-uranium closed fuel cycles is generally recognized.
The role of the development and implementation of a new generation of fast neutron nuclear fuel breeder reactors and new methods of nuclear fuel reprocessing to close the nuclear fuel cycle and solve the problem of virtually unlimited fuel supply for nuclear power is important. The recognized advanced level of fast reactor technology in Russia, the only country operating a commercial reactor of this type, combined with experience in nuclear fuel reprocessing, will allow Russia in the long term to claim the role of one of the leaders in global nuclear energy, providing services for the production and reprocessing of nuclear fuel to many countries around the world. while simultaneously reducing the risk of proliferation of nuclear weapons, including through energy utilization of “weapons-grade” plutonium.
A necessary and mandatory condition for solving this problem is, first of all, the development of a completely closed nuclear fuel cycle, which will require quite serious investments in:
- complex for the production of plutonium fuel for fast reactors and MOX fuel for VVER reactors;
- plutonium fuel processing complex;
- complex for the production and processing of thorium fuel.
The issue of constructing a nuclear power plant with BN-800 is currently difficult to resolve. Construction requires many costs. The following are given as arguments in favor of the need for the speedy construction of the BN-800:
- processing of uranium-plutonium fuel;
- energy utilization of “surplus” weapons-grade plutonium;
- preservation of knowledge and experience in the development of fast reactors in Russia.
At the same time, specific capital investments and the cost of supplied electricity for BN-800 significantly exceed those of nuclear power plants with VVER reactors.
In addition, it seems expensive to carry out the entire complex of production to close the fuel cycle and use it only for one BN-800.
It is impossible to fully realize the benefits of nuclear energy without its participation in the production of artificial liquid fuel for transport and other industrial applications. The creation of nuclear power plants with high-temperature helium reactors is a way to use nuclear energy to produce hydrogen and its widespread use in the era of the hydrogen economy. To achieve this goal, it is necessary to complete the development of the project and create a demonstration unit for the development of high-temperature helium-cooled reactors capable of generating heat at temperatures up to 1000 ° C, for the production of electricity with high efficiency in the gas turbine cycle and for supplying high-temperature heat and electricity to hydrogen production processes, and also technological processes of water desalination, chemical, oil refining, metallurgical and other industries.
Most analysts recognize that the innovation challenges of nuclear power must be addressed over the next two decades in order to ensure the commercial introduction of new technologies in the thirties of this century.
Thus, today we are faced with an urgent need to develop and implement technological innovations that ensure the long-term and large-scale development of the country’s nuclear energy, nuclear technologies that ensure the implementation of their historical role in the future of Russia. Solving this problem is impossible alone. Active cooperation with the global nuclear community is required. However, this world community is showing its intention to leave us on the side of the nuclear road.
Developing innovative nuclear technologies is a difficult, capital-intensive task. Its solution is beyond the power of one country. Therefore, cooperation in the development of innovative nuclear technologies is emerging in the world community - both at the intergovernmental level and at the level of industrial companies. It is indicative of this
in relation to the Agreement on the development of new generation nuclear energy systems signed on February 28, 2005 by the USA, England, France, Japan and Canada: fast helium reactor; fast sodium reactor; fast lead reactor; molten salt reactor; light water reactor with supercritical parameters; ultra-high temperature reactor. Russia, which has unique experience in some of these technologies, is not participating in this partnership. What is this: temporary excommunication or a stable position of our Western partners?
NECESSARY ACTIONS
An active state policy is needed in the country's fuel and energy complex, aimed at ensuring the accelerated development of nuclear technology: with a concentration of efforts and funds to increase state support in investment policy and in innovative nuclear power projects.
It is necessary to form financial and economic mechanisms to support and stimulate innovative activities in the field of nuclear energy.
It is obvious that the market, without additional measures of government regulation, does not lead the country’s economy onto a high-tech development trajectory, and nuclear energy and the nuclear fuel cycle are one of the areas of structural shift in the country’s economy and breakthrough technologies of the 21st century.
It seems necessary to restore effective corporate ties in the chain “science – project – industry” based on economic methods while strengthening the role of leading state scientific centers, which are and will be “collective experts” guaranteeing the competence of decisions of state structures in the field of nuclear technology.
There is a need to prioritize innovative projects (including with the active participation of Russian experts in the international IAEA INPRO project), concentrate efforts (financial and organizational) on technologies and achievements that can provide Russia with a worthy place in the international nuclear technology market and expand the country’s export capabilities. It is necessary to establish international cooperation to develop new generation nuclear systems.
It is necessary to ensure the accumulation, preservation and transfer of knowledge and experience in the nuclear field, with the active involvement of researchers in the nuclear industry through economic (financial, etc.) and organizational incentives for students, graduate students and the attraction of leading engineers, researchers and scientists to work in the “lead” nuclear universities and departments of the country: MEPhI, OIATE, MVTU, MPEI, MIPT, MAI, MSU, etc. The practical implementation of the task of preserving nuclear knowledge and experience can be achieved through the development, approval and implementation of a “national program” in this area, the creation of the Russian Nuclear Center knowledge and technology (integrated scientific and educational center).
CONCLUSION
The long-term interests of Russia's energy and national security, as well as the country's sustainable development, require an increase in the share of nuclear energy in the production of electricity, hydrogen, industrial and domestic heat. The vast technological experience and scientific and technical potential accumulated over 50 years of nuclear power in the country allow Russia, under appropriate conditions and innovation policy, to reach the “nuclear forefront” and become one of the leaders of the next nuclear era for the benefit of its people, as well as a leading supplier of nuclear technologies, equipment, knowledge and experience to developing countries.
THE END OF CAPITALISM IS INEVITABLE
So far, the current nuclear energy industry in the world uses uranium, which exists in the form of two isotopes: uranium-238 and uranium-235. Uranium-238 has three more neutrons. Therefore, in nature (due to the peculiarities of the genesis of our Universe) there is much more uranium-238 than “235”. Meanwhile, for nuclear energy - for a chain reaction to occur - it is uranium-235 that is needed. It is on this isotope, isolated from the mass of natural uranium, that nuclear energy is being developed to this day.
THE ONLY POSITIVE PROGRAM
The only promising direction in which nuclear energy can be developed is the forced fission of uranium-238 and thorium-232. In it, neutrons are taken not as a result of a chain reaction, but from outside. From a powerful and compact accelerator attached to the reactor. These are the so-called YRES - nuclear relativistic nuclear power plants. Igor Ostretsov and his team are supporters of the development of this particular direction, considering it the most cost-effective (use of natural uranium-238 and thorium) and safe. Moreover, YRES can be a mass phenomenon.
However, it was precisely for trying to convey this idea to the top leadership of the Russian Federation and for declaring all three directions of Rosatom’s development to be dead ends that I. Ostretsov was expelled from the Presidential Commission on Modernization. And his Institute of Nuclear Engineering went bankrupt.
This is a long-standing idea - to adapt an accelerator of elementary particles to a nuclear reactor and obtain completely safe energy. That is, the result is an explosion-proof reactor where there is no supercritical mass of fissile products. Such a reactor can operate on uranium from waste dumps of radiochemical plants, natural uranium and thorium. The nucleon flows from the accelerator play the role of an activator-igniter. Such subcritical reactors will never explode; they do not produce weapons-grade plutonium. Moreover, they can “afterburn” radioactive waste and irradiated nuclear fuel (fuel rods). Here it is possible to completely process long-lived actinide products from fuel elements (fuel elements) of submarines and old nuclear power plants into short-lived isotopes. That is, the volume of radioactive waste decreases significantly. In fact, it is possible to create a new type of safe nuclear energy - relativistic. At the same time, forever solving the problem of shortage of uranium for stations.
There was only one catch: the accelerators were too large and energy-hungry. They killed the entire “economy”.
But in the USSR, by 1986, so-called linear backward-wave proton accelerators, quite compact and efficient, had been developed. Work on them was carried out at the Siberian Branch of the USSR Academy of Sciences by Physics and Technology student A.S. Bogomolov (a fellow student of I. Ostretsov at Physics and Technology) as part of the creation of beam weapons: a Russian asymmetric and cheap answer to the American “star wars” program. These vehicles fit perfectly into the cargo compartment of the heavy Ruslan aircraft. Looking ahead, let's say in one technological variant they are the possibility of creating safe and very cost-effective electronuclear stations. In another option, reverse wave accelerators can detect a nuclear warhead (nuclear power plant) from a great distance and disable its devices, causing the destruction of the core or nuclear warhead. In essence, these are the very things that people from Igor Nikolaevich Ostretsov’s team are proposing to build in the Russian Federation today.
If we go back in time, the accelerators based on the backward wave of Academician Bogomolov received the name BWLAP in the West - Backward Wave Linear Accelerator for Protons. The Americans, in 1994, studying the scientific and technical heritage of the defeated USSR and looking for anything valuable to remove from its wreckage, highly appreciated the accelerators from Siberia.
LOST YEARS
In essence, under normal government, the Russians could have developed YRT technology already in the 1990s, obtaining both ultra-efficient nuclear energy and unprecedented weapons.
Before me are letters sent in 1994 and 1996 to the then First Deputy Prime Minister Oleg Soskovets by two legendary Soviet academicians - Alexander Savin and Gury Marchuk. Alexander Savin is a participant in the USSR nuclear project under the leadership of Lavrenty Beria and Igor Kurchatov, a Stalin Prize laureate and subsequently the head of the Central Research Institute "Kometa" (satellite warning systems for nuclear missile attacks and IS satellite fighters). Guriy Marchuk is a major organizer of work in computer technology, the former head of the State Committee for Science and Technology (GKNT) of the Soviet Union.
On April 27, 1996, Alexander Ivanovich Savin writes to Soskovets that, under the leadership of the Central Research Institute "Kometa", leading teams of the USSR Academy of Sciences and the Defense Ministries were working on the creation of "advanced technologies for creating beam missile defense systems." This is precisely why the BWLAP accelerator was created. A. Savin outlines the areas of possible application of this technology: not only the construction of safe nuclear power plants, but also the creation of highly sensitive complexes for detecting explosives in luggage and containers, and the creation of means for processing long-lived radioactive waste (actinides) into short-lived isotopes, and a radical improvement in methods of radiation therapy and diagnosis of cancer using proton beams.
And here is a letter from Guriy Marchuk to the same O. Soskovets dated December 2, 1994. He says that the Siberian Branch of the Academy of Sciences has long been ready for work on creating nuclear power plants with subcritical reactors. And back in May 1991, G. Marchuk, as President of the USSR Academy of Sciences, addressed M. Gorbachev (material 6618 of the Special Folder of the President of the USSR) with a proposal “on the large-scale deployment of work on linear accelerators - dual-use technologies.” The points of view of such academician-general designers as A.I. Savin and V.V. Glukhikh, as well as vice-presidents of the Academy of Sciences V.A. Koptyug and R.V. Petrov and other scientific authorities were concentrated there.
Guriy Ivanovich argued to Soskovets: let’s expand accelerator construction in the Russian Federation, solve the problem of radioactive waste, use the sites of the Ministry of Atomic Energy of the Russian Federation in Sosnovy Bor. Fortunately, both the head of Minatom V. Mikhailov and the author of the backward wave acceleration method A. Bogomolov agree to this. For the alternative to such a project is only the acceptance of American proposals “received by the Siberian Branch of the Russian Academy of Sciences, ... to carry out work with funds and under the full control of the United States with their transfer and implementation in the national laboratories of their country - in Los Alamos, Argonne and Brookhaven. We cannot agree to this..."
At the end of 1994, Marchuk proposed to involve both Sosnovy Bor and the St. Petersburg NPO Electrophysics in the project, thereby marking the beginning of an innovative economy: the influx of “much-needed foreign currency funds from foreign consumers... due to the development of products in a highly scientifically saturated sector...” That is, the Soviet In this regard, the bison was a good 10-15 years ahead of the Russian authorities: after all, the article “Forward Russia!” came out only in the fall of 2009.
But then the Soviet scientific bison were not heard. Already in 1996, A. Savin informed O. Soskovets: they did not give money, despite your positive response in 1994, despite the support of the State Committee for Defense Industry and the Ministry of Atomic Energy of the Russian Federation. The Phystechmed program is worth it. Give me 30 million dollars...
Not allowed…
Today, if we implement the program with the basic All-Russian Scientific Research Institute of Nuclear Engineering, then the program for creating a new generation of nuclear power plants (YARES - nuclear relativistic stations) will take a maximum of 12 years and require 50 billion dollars. Actually, 10 billion of them will be spent on the development of modern reverse wave accelerators. But the sales market here is over 10 trillion “green”. At the same time, super-powerful but safe nuclear power plants must be created for ships (both surface and underwater), and in the future – for spacecraft.
It is only necessary to revive the program for building accelerators on the reverse wave. Maybe even on the terms of international cooperation.
HOW MANY NEW BLOCKS DO YOU NEED?
According to I. Ostretsov, there is simply no alternative to the relativistic direction in nuclear energy. At least half a century ahead. Nuclear relativistic ES are safe and clean.
They could become an export commodity and a means to quickly and cheaply provide the whole world with fairly cheap and clean energy. No solar or wind power stations are competitors here. To achieve a decent standard of living, a person needs 2 kilowatts of power. That is, for the entire population of the planet (in the future - 7 billion souls) you need to have 14 thousand nuclear power units of one million kW each. And now there are only 4 thousand of them (old types, not YRT), if you count each block as a million-plus. It is no coincidence that in the 1970s the IAEA spoke about the need to build 10 thousand reactors by the year 2000. Ostretsov is confident: these should only be nuclear reactors operating on natural uranium and thorium.
There is no need to accumulate fuel here - and you can immediately build as many blocks as needed. At the same time, nuclear reactor stations do not produce plutonium. There is no problem of nuclear weapons proliferation. And the fuel itself for nuclear energy is falling in price many times over.
OSTRETSOV FACTOR
Today the leader of those who are trying to develop YRT in the Russian Federation is Igor Ostretsov.
During the Soviet years, he was a successful researcher and designer. Thanks to him, in the 1970s, plasma invisibility equipment was born for ballistic missile warheads, and then for the X-90 “Meteor” cruise missile. Suffice it to say that thanks to the lithium plasma accelerator in the Matsesta experiment, the Soyuz-class spacecraft disappeared from the radar screen (reducing the radio visibility of the spacecraft by 35-40 decibels). Subsequently, the equipment was tested on a “Satan” type rocket (in his book, I. Ostretsov warmly recalls the help he received from the assistant to the general designer of the rocket, Leonid Kuchma). When the Matsesta was turned on, the missile warhead simply disappeared from the radar screens. The plasma that enveloped the “head” in flight scattered the radio waves. These works of I. Ostretsov are still extremely important today - for breaking through the promising US missile defense system. Until 1980, Igor Ostretsov carried out successful work on creating plasma equipment for the Meteorite hypersonic high-altitude cruise missile. Here the radio waves were not scattered by the plasma (because the rocket was flying in the atmosphere), but were absorbed by it. But that's a different story.
In 1980, Igor Ostretsov went to work at the Research Institute of Nuclear Engineering. It was there that he thought about the problem of creating the cleanest possible nuclear energy with a minimum of waste and not producing fissile materials for nuclear weapons. Moreover, one that would not use rare uranium-235.
The solution to the problem lay in a little-studied area: in the effect of high-energy neutrons on “non-fissile” actinides: thorium and uranium-238. (They fission at energies greater than 1 MeV.) “In principle, neutrons of any energy can be produced using proton accelerators. However, until recently, accelerators had extremely low efficiency factors. Only at the end of the twentieth century did technologies emerge that made it possible to create proton accelerators of sufficiently high efficiency…” the researcher himself writes.
Thanks to his acquaintance with academician Valery Subbotin, tied to the liquidation of the Chernobyl accident, I. Ostretsov was able to conduct an experiment in 1998 at the Institute of Nuclear Physics in Dubna. Namely, the processing of a lead assembly using a large accelerator with a proton energy of 5 gigaelectron-volts. Lead began to divide! That is, the possibility of creating nuclear energy (a combination of an accelerator and a subcritical reactor) was fundamentally proven, where neither uranium-235 nor plutonium-239 was needed. With great difficulty, it was possible to carry out the 2002 experiment at the accelerator in Protvino. A 12-hour treatment of a lead target at an accelerator in the energy range from 6 to 20 GeV led to the fact that lead... 10 days “phonyl” as a radioactive metal (8 roentgens is the dose value on its surface at first). Unfortunately, I. Ostretsov was not given the opportunity to conduct similar experiments with thorium and uranium-238 (actinides). Strange opposition from the Russian Ministry of Atomic Energy began. But the main thing was proven: nuclear relativistic energy using “rough” types of fuel is possible.
ON THE THRESHOLD OF A POSSIBLE ENERGY BREAKTHROUGH
One thing was missing: a small but powerful accelerator. And it was found: it was a Bogomolov accelerator on a backward wave. As I. Ostretsov writes, subcritical reactors with accelerators will make it possible to achieve the highest concentration of fissile nuclei - almost one hundred percent (at 2-5% in current reactors and at 20% in fast neutron reactors).
Nuclear relativistic power plants (NRES) will be able to use the colossal reserves of thorium in the Russian Federation (1.7 million tons). After all, just 20 km from the Siberian Chemical Plant (Tomsk-7) there is a giant thorium deposit, next to it there is a railway and the infrastructure of a powerful chemical plant. YRES can operate for decades on one reactor load. At the same time, unlike fast neutron reactors, they do not produce “nuclear explosives”, which means they can be safely exported.
In the early 2000s, Igor Ostretsov learned about A. Bogomolov’s compact linear accelerators, met him - and they patented essentially a new nuclear energy technology. We calculated the required capital investments, estimated the work program and those who would perform them. So the period for creating the first YRES is no more than 12 years.
And the reverse wave accelerators themselves are a super innovation. The Bogomolov machine, the size of a trolleybus, fits on board the Ruslan, and becomes a detector of nuclear weapons at a great distance - and can destroy them with a beam of protons. This is, in fact, a beam weapon that can be made even more advanced and long-range. But in the near future it will be possible to create technology for detecting nuclear charges transported by saboteurs and terrorists (for example, on civilian ships) and for destroying them with a directed beam of particles. There are calculations showing: a beam of neutrons can destroy the ship reactor of a target ship in a millisecond, turning it into a “mini-Chernobyl” due to frantic acceleration.
And, of course, YRT includes plasma technologies of radio invisibility - for missiles and aircraft of the future Russia.
The only thing left to do is to create a state scientific center for nuclear relativistic energy and the development of nuclear radiation technologies. For no private capital has the right to work in such an area, which, moreover, has a pronounced “double” character. The game is worth the candle: having developed nuclear energy, the Russians will become its monopolists and reap exorbitant profits from a completely new market. What is the cost of just the business of completely processing, with the help of Yares, long-lived nuclear waste remaining after the closure of old nuclear power plants! This is hundreds of billions of dollars.
DOSSIER. From a letter from Deputy of the State Duma of the Russian Federation Viktor Ilyukhin to President Dmitry Medvedev.
“...For ten years, our country has been working on nuclear relativistic technologies (NRT), based on the interaction of charged particle beams obtained using accelerators with the nuclei of heavy elements.
Nuclear power technologies are developing in five main areas: 1) energy; 2) military applications, primarily beam weapons; 3) remote inspection of unauthorized transportation of nuclear materials; 4) fundamental physics; 5) various technological, in particular medical applications.
The tool for implementing YRT is the modular compact backward wave accelerator (BWLAP).
Russian patents were obtained for accelerator and nuclear radiation technologies based on protons and heavy, including uranium, nuclei (I.N. Ostretsov and A.S. Bogomolov).
An examination of the possibility of creating beam weapons based on nuclear radiation technologies was carried out by specialists from the 12th Main Directorate of the Russian Ministry of Defense and Rosatom, who confirmed the reality of creating beam weapons based on nuclear radiation, far superior in all respects to beam weapons created today by advanced countries (USA, China, Japan, France).
Thus, at present, only Russia can create a combat complex, the creation of which all developed countries are striving to create and which can radically change the methods of warfare and the balance of power in the world.
On the issue of developing work on nuclear radiation technologies, on December 6, 2008, a meeting was held with the Chairman of the Federation Council of the Federal Assembly of the Russian Federation S.M. Mironov with the participation of the leadership of the 12th Main Directorate of the Russian Ministry of Defense, responsible representatives of the Federation Council of the Russian Federation, the VNIIEF nuclear center (Sarov) and the authors of nuclear radiation technologies..."
SAD REALITY
Now the paths of Ostretsov and Bogomolov have diverged. The state did not finance work on Russian reverse-wave accelerators. And we had to look for Western customers. Bogomolov’s BWLAP technology does not belong to him alone. And others found customers in the USA. Fortunately, the pretext is good - to develop technology for long-range detection of nuclear charges in the name of the fight against international terrorism. A new (from Eref’s times, 2003 model) academician Valery Bondur took up the matter. General Director of the state institution - Scientific Center for Aerospace Monitoring "Aerospace" of the Ministry of Education and Science and the Russian Academy of Sciences, editor-in-chief of the journal "Earth Exploration from Space". As Viktor Ilyukhin and Leonid Ivashov wrote to the President of the Russian Federation, “Currently, our country has completed work on theoretical and experimental research into the method of remote inspection of nuclear materials under a contract with the US company DTI (CIA). Agreement No. 3556 dated June 27, 2006 was carried out by the company "Isintek", academician Bondur V.G. (Appendix 1) with the support of the FSB of the Russian Federation. Now in the USA (Los Alamos Laboratory) a decision has been made to create a real inspection and combat system based on the work carried out in our country.
According to Russian law, works of this class must undergo examination by the 12th Institute of the 12th State Administration of the Ministry of Defense of the Russian Federation before being transferred abroad. This provision is being flagrantly violated with the full connivance of the Administration of the President of the Russian Federation, the Security Council of the Russian Federation and Rosatom.
This program, if implemented, will allow our country, together with the states to which the remote inspection system will be installed, to control the proliferation of nuclear materials throughout the world, for example, within the framework of an international organization to combat nuclear terrorism, which would be advisable to be headed by one of Russia’s top leaders. Moreover, all work will be financed from foreign funds.
We ask you, dear Dmitry Anatolyevich, to give instructions to immediately conduct an examination of the materials transferred to the United States and establish the circle of persons involved in this unprecedented violation of the fundamental interests and security of the Russian Federation. For this purpose, create a working group consisting of representatives of your administration, the 12th Main Directorate of the RF Ministry of Defense and the authors of this letter..."
Thus, the fruits of the dedicated work of domestic innovating physicists may go to the United States. And there, and not here, nuclear relativistic technologies will develop - the energy and weapons of the next era...
WHO DOES THE CURRENT ROSATOM WORK FOR?
Well, for now Rosatom is busy working mainly in the interests of the United States.
Do you know why he doesn’t want to notice the true perspective in development? Because its main function is the transfer of Soviet reserves of uranium-235 to American nuclear power plants (HEU-LEU deal, Gore-Chernomyrdin, 1993).
Why does Rosatom buy ownership stakes in foreign natural uranium mining enterprises? In order to enrich it at our enterprises built in the USSR (and therefore cheap) - and again supply fuel for nuclear power plants to America. The United States thereby minimizes its electricity production costs. Yes, and irradiated nuclear fuel - SNF - will be sent from the West to the Russian Federation for recycling.
What is the prospect here? The prospect for Russia is purely colonial...
Basic nuclear technologies Nuclear technologies are technologies based on the occurrence of nuclear reactions, as well as technologies aimed at changing the properties and processing of materials containing radioactive elements or elements on which nuclear reactions occur Nuclear energy technologies: - Technologies of nuclear reactors using thermal neutrons -Technologies of fast neutron nuclear reactors -Technologies of high- and ultra-high-temperature nuclear reactors
Nuclear chemical technologies: - Technologies of nuclear raw materials and nuclear fuel - Technologies of materials of nuclear technology Nuclear technologies of isotope enrichment and production of monoisotopic and high-purity substances: - Gas diffusion technologies - Centrifuge technologies - Laser technologies Nuclear medical technologies
The growth of population and global energy consumption in the world, an acute shortage of energy, which will only increase as natural resources are depleted and the demand for it grows faster; Increasing competition for limited and unevenly distributed fossil fuel resources; aggravation of a complex of environmental problems and increasing environmental restrictions; increasing dependence on the unstable situation in the regions of oil-exporting countries and the progressive increase in hydrocarbon prices; Provisions that are immutable for making forecasts in the field of future scenarios:
The growing difference in the level of energy consumption of the richest and poorest countries, the difference in the levels of energy consumption of different countries, creating the potential for social conflict; fierce competition between technology suppliers for nuclear power plants; the need to expand the scope of application of nuclear technologies and large-scale energy technology use of nuclear reactors for production areas; the need to carry out structural changes and reforms in the harsh conditions of a market economy, etc. Provisions that are unshakable for making forecasts in the field of future scenarios:
Shares of countries in global CO 2 emissions USA - 24.6% China - 13% Russia - 6.4% Japan - 5% India - 4% Germany - 3.8%. A nuclear power plant with an electrical capacity of 1 GW saves 7 million tons of CO 2 emissions per year compared to coal-fired thermal power plants, and 3.2 million tons of CO 2 emissions compared to gas-fired thermal power plants.
Nuclear evolution There are about 440 commercial nuclear reactors operating around the world. Most of them are located in Europe and the USA, Japan, Russia, South Korea, Canada, India, Ukraine and China. The IAEA estimates that at least 60 more reactors will come online within 15 years. Despite the variety of types and sizes, there are only four main categories of reactors: Generation 1 - reactors of this generation were developed in the 1950s and 1960s, and are modified and enlarged nuclear reactors for military purposes, intended for the propulsion of submarines or for production plutonium Generation 2 – the vast majority of reactors in commercial operation belong to this classification. Generation 3 – reactors of this category are currently being commissioned in some countries, mainly in Japan. Generation 4 – this includes reactors that are at the development stage and which are planned to be introduced in a few years.
Nuclear evolution Generation 3 reactors are called "advanced reactors". Three such reactors are already operating in Japan, and more are under development or construction. There are about twenty different types of reactors of this generation under development. Most of them are “evolutionary” models, developed on the basis of second generation reactors, with changes made based on innovative approaches. According to the World Nuclear Association, Generation 3 is characterized by the following points: A standardized design for each type of reactor allows speeding up the licensing procedure, reducing the cost of fixed assets and the duration of construction work. Simplified and more robust design, making them easier to handle and less susceptible to failures during operation. High availability and longer service life - approximately sixty years. Reducing the possibility of accidents with core melting. Minimal impact on the environment. Deep fuel burnout to reduce fuel consumption and production waste. Generation 3
Third Generation Nuclear Reactors European Pressurized Water Reactor (EPR) The EPR is a model developed from the French N4 and the German KONVOI, second generation designs commissioned in France and Germany. Ball Bed Modular Reactor (PBMR) PBMR is a high temperature gas cooled reactor (HTGR). Pressurized water reactor The following types of large reactor designs are available: APWR (developed by Mitsubishi and Westinghouse), APWR+ (Japanese Mitsubishi), EPR (French Framatome ANP), AP-1000 (American Westinghouse), KSNP+ and APR- 1400 (Korean companies) and CNP-1000 (China National Nuclear Corporation). In Russia, the companies Atomenergoproekt and Gidropress have developed an improved VVER-1200.
Reactor concepts selected for Generation 4 GFR - Gas-cooled fast reactor LFRLead-cooled fast reactor MSR - Molten salt reactor: Uranium fuel is melted in sodium fluoride salt circulating through the graphite channels of the core. The heat generated in the molten salt is removed to the secondary circuit Sodium-cooled fast reactor VHTR - Ultra-high temperature reactor: Reactor power 600 MW, core cooled with helium, graphite moderator. It is considered as the most promising and promising system aimed at producing hydrogen. VHTR power generation is expected to become highly efficient.
Scientific research is the basis for the activity and development of the nuclear industry All practical activities of nuclear energy are based on the results of fundamental and applied research into the properties of matter Fundamental research: fundamental properties and structure of matter, new energy sources at the level of fundamental interactions Research and control of material properties - Radiation materials science, creation of structural corrosion-resistant, heat-resistant, radiation-resistant steels, alloys and composite materials
Scientific research is the basis for the activity and development of the nuclear industry. Design, design, technology. Creation of devices, equipment, automation, diagnostics, control (general, medium and precision engineering, instrument making) Process modeling. Development of mathematical models, calculation methods and algorithms. Development of parallel computing methods for conducting neutronics, thermodynamic, mechanical, chemical and other computational studies using supercomputers
AE in the medium term The world is expected to double nuclear power capacity by 2030. The expected increase in nuclear power capacity can be achieved based on further development of thermal neutron reactor technologies and open-loop nuclear fuel cycle. The main problems of modern nuclear power plant are related to the accumulation of spent nuclear fuel (this is not radioactive waste!) and the risk of proliferation in world of sensitive technologies of nuclear fuel cycle and nuclear materials
Tasks for creating a technological base for large-scale nuclear power plants Development and implementation of fast neutron breeder reactors in nuclear power plants Complete closure of the nuclear fuel cycle in nuclear power plants for all fissile materials Organization of a network of international nuclear fuel and energy centers to provide a range of services in the field of nuclear fuel cycle Development and implementation of reactors in nuclear power plants for industrial heat supply, hydrogen production, water desalination and other purposes Implementation of an optimal scheme for recycling highly radiotoxic minor actinides in nuclear power plants
PRODUCTION AND APPLICATION OF HYDROGEN During the oxidation of methane on a nickel catalyst, the following main reactions are possible: CH 4 + H 2 O CO + ZH 2 – 206 kJ CH 4 + CO 2 2 CO + 2H 2 – 248 kJ CH 4 + 0.5 O 2 CO + 2H kJ CO + H 2 O CO 2 + N kJ High-temperature conversion is carried out in the absence of catalysts at temperatures °C and pressures up to 3035 kgf/cm 2, or 33.5 Mn/m 2; in this case, almost complete oxidation of methane and other hydrocarbons with oxygen to CO and H 2 occurs. CO and H 2 are easily separated.
PRODUCTION AND APPLICATION OF HYDROGEN Reduction of iron from ore: 3CO + Fe 2 O 3 2Fe + 3CO 2 Hydrogen is capable of reducing many metals from their oxides (such as iron (Fe), nickel (Ni), lead (Pb), tungsten (W) , copper (Cu), etc.). So, when heated to a temperature of °C and above, iron (Fe) is reduced with hydrogen from any of its oxides, for example: Fe 2 O 3 + 3H 2 = 2Fe + 3H 2 O
Conclusion Despite all its problems, Russia remains a great “nuclear” power, both in terms of military power and in terms of economic development potential (nuclear technology in the Russian economy). The nuclear shield is a guarantor of Russia’s independent economic policy and stability throughout the world. The choice of the nuclear industry as the engine of the economy will first allow mechanical engineering, instrument making, automation and electronics, etc. to be brought up to a decent level, during which there will be a natural transition from quantity to quality.
FEDERAL AGENCY FOR EDUCATION
MOSCOW ENGINEERING PHYSICS INSTITUTE (STATE UNIVERSITY)
V.A. Apse A.N. Shmelev
For university students
Moscow 2008
UDC 621.039.5(075) BBK 31.46ya7 A77
Apse V.A., Shmelev A.N. Nuclear technologies: Tutorial. M.:
MEPhI, 2008. – 128 p.
A brief description of the main technologies of the modern nuclear fuel cycle is presented: from the extraction of uranium ore to the disposal of radioactive waste. The main attention is paid to the basic principles embedded in each technology, a description of the equipment used and the conditions for the implementation of the technological process. An analysis of the significance of each technology for maintaining the nuclear non-proliferation regime is given.
The manual is intended for students specializing in the field of accounting, control of nuclear materials and physical protection of nuclear hazardous facilities, for methodological support of the master's educational program "FZU and K NM" in the direction of "Technical Physics", training of physicist engineers in specialty 651000 in the direction of "Nuclear Physics and Technologies" "and future nuclear fuel cycle specialists.
The manual was prepared as part of the Innovative Educational Program.
Reviewer: Dr. Phys.-Math. Sciences Yu.E. Titarenko
ISBN 978-5-7262-1031-5 © Moscow Engineering Physics Institute (State University), 2008
Introduction........................................................ ................................................... |
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Chapter 1. Nuclear fuel concept.................................................... ..... |
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Chapter 2. The concept of the nuclear fuel cycle.................................... |
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Chapter 3. Extraction and primary processing of natural nuclear materials...... |
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Chapter 4. Isotope enrichment of uranium.................................................... .. |
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Chapter 5. Manufacturing technologies for fuel rods and fuel assemblies.................................... |
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Fuel use technology |
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nuclear reactors........................................................ ............... |
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Transportation of irradiated fuel................................... |
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Technologies for processing irradiated nuclear |
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fuel........................................................ ................................ |
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Technologies for processing radioactive waste.......... |
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Bibliography................................................ ............................... |
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INTRODUCTION
The subject of the course is nuclear technologies, or technologies for handling nuclear materials (NM), which usually include those substances without which it is impossible to initiate and proceed two self-sustaining nuclear reactions, accompanied by the release of a large amount of energy.
1. Chain reaction of fission of nuclei of heavy isotopes.
For example, when the 235 U isotope is fissioned by neutrons, two fission products are formed, 2–3 neutrons capable of continuing the reaction and approximately 200 MeV of thermal energy is released:
235 U + n → PD1 + PD2 + (2–3)n + 200 MeV.
Therefore, nuclear materials include isotopes of uranium and thorium (from natural elements), isotopes of artificial transuranium elements (mainly plutonium, as well as isotopes Np, Am, Cm, Bk Cf). This also includes 233 U, an artificial isotope of uranium, which can be obtained by neutron irradiation of thorium.
2. The reaction of thermonuclear fusion of nuclei of light isotopes.
For example, when deuterium and tritium interact, helium nuclei and neutrons are formed and approximately 21 MeV of thermal energy is released:
D + T → 4 He + n + 21 MeV.
Therefore, nuclear isotopes include hydrogen isotopes: deuterium and tritium. Natural hydrogen contains 0.015% deuterium. Tritium is not found in natural hydrogen due to its rapid decay (half-life T1/2 = 12.3 g). Heavy water (D2 O) and lithium are also classified as nuclear materials, because the lithium isotope 6 Li is capable of intensively producing tritium in the reaction 6 Li(n,α )T. The cross section for the (n,α) reaction of 6 Li for thermal neutrons is 940 barn. Content of 6 Li in natural lithium –
Thus, NM include:
1) source NM – uranium and thorium ores, natural uranium
And thorium, depleted uranium (uranium with reduced content 235 U);
2) special nuclear materials – enriched uranium (uranium with increased content 235 U), plutonium of any isotopic composition and 233 U;
3) transuranic elements (Np, Am, Cm, Bk, Cf);
4) heavy water, deuterium, tritium, lithium.
The first three categories of nuclear materials are associated with nuclear energy, based on the fission reaction of heavy nuclei by neutrons, and the fourth – with the thermonuclear reaction of light isotopes. Since the creation of power plants based on this reaction remains an unsolved problem, the course will focus on technologies based on nuclear materials of the first three categories.
Nuclear technologies include technologies for the production of nuclear materials, their storage, use, transportation, processing, possible reuse of regenerated nuclear materials or their disposal if further use is impossible.
Much attention in the course will be paid to the connection of nuclear technologies with issues of safe handling of nuclear materials. The term “safety” in relation to nuclear materials can be used in a broad sense, including radiation safety, nuclear safety and safety regarding the proliferation of nuclear weapons.
Under radiation safety refers to protection from damaging factors of direct exposure to all types of ionizing radiation.
Under nuclear safety is understood as preventing a critical state of a system containing NM, i.e. preventing the occurrence of a self-sustaining fission chain reaction. A nuclear safety violation could result in a nuclear explosion, a thermal explosion, or, at a minimum, a radiation outbreak and overexposure of personnel.
Under safety in relation to the proliferation of nuclear materials,
security against theft of nuclear materials for the purpose of creating nuclear explosive devices or radiological weapons is required. The IAEA currently uses the term “Nuclear security” to refer to this type of safety, as opposed to the term “Nuclear safety”, which refers to the nuclear safety mentioned above.
The main focus of this course will be on the description of nuclear technologies and their analysis from the point of view of ensuring non-
distribution of nuclear materials, i.e. from a nuclear security perspective. The non-proliferation of nuclear materials can be guaranteed if, when working with them, such conditions are created that the theft and use of nuclear materials for illegal purposes becomes so difficult and dangerous, and the risk of detection of such actions is so high that potential violators would be forced to abandon their intentions.
This means that nuclear technologies must be provided with such a system of physical protection, accounting and control of nuclear materials so that:
a) it was very difficult to get to the YAMs and steal them; b) any theft of a small amount of nuclear material by facility personnel
was quickly discovered, and further attempts at theft were stopped;
c) authorized theft of nuclear materials was easily detected by national or international inspection authorities.
So, the main topic of the course is nuclear technology from the point of view of nuclear non-proliferation.
The following main issues will be discussed below:
1. Nuclear fuel cycle (NFC). Review of the main stages of the nuclear fuel cycle from the extraction of natural nuclear materials to the disposal of radioactive waste (RAW).
2. Technologies for extraction and primary processing of natural nuclear materials.
3. Reserves in deposits of natural nuclear materials and the rate of their production.
4. Nuclear material enrichment technologies for the production of nuclear fuel. Enrichment technologies from a nonproliferation perspective.
5. Methodology for calculating the labor intensity and energy intensity of enrichment technologies. Separation works. Energy intensity of separation operations in different technologies.
6. Technologies for manufacturing nuclear fuel, fuel rods and fuel assemblies.
7. Technologies for using nuclear materials in nuclear reactors. Strategies for reloading operations.
8. Temporary storage of irradiated nuclear fuel (SNF) at nuclear power plants and its transportation.
9. Technologies for chemical processing of spent nuclear fuel. Reprocessing technologies with increased protection against nuclear material proliferation.
10. Technologies for processing and disposal of radioactive waste. Projects for the creation of radioactive waste storage facilities in geological formations.
Chapter 1. NUCLEAR FUEL CONCEPT
Nuclear fuel is nuclear material containing nuclides that fission when interacting with neutrons. Fissile nuclides are:
1) natural isotopes of uranium and thorium;
2) artificial isotopes of plutonium (products of sequential capture of neutrons by isotopes, starting with 238 U);
3) isotopes of transuranic elements (Np, Am, Cm, Bk, Cf);
4) artificial isotope 233 U (neutron capture product of thori-
As a rule, isotopes of uranium, plutonium and thorium with an even mass number (“even” isotopes 238 U, 240 Pu, 242 Pu, 232 Th) are fissile
only high-energy neutrons (the fission reaction threshold for them is approximately 1.5 MeV). At the same time, isotopes of uranium and plutonium with an odd mass number (“odd” isotopes 235 U, 239 Pu, 241 Pu, 233 U) are fissioned by neutrons of any energy, including thermal neutrons. Moreover, the lower the neutron energy, the higher the microsections for fission of odd isotopes.
The spectrum of neutrons emitted during fission is a spectrum of fast neutrons (average energy 2.1 MeV) that rapidly slow down below the fission threshold of even-numbered isotopes. This means that a fission chain reaction on even isotopes is difficult to achieve, since only a small fraction of neutrons have energies above the fission threshold of these isotopes. At the same time, to maintain a chain reaction on odd isotopes, it is desirable to slow down fission neutrons to thermal energy, which is quite realistic.
Nuclear fuel containing only natural fissile isotopes (235 U, 238 U, 232 Th) is called primary. Nuclear fuel containing fissile nuclides obtained artificially (233 U, 239 Pu, 241 Pu) is called secondary.
The isotopes 238 U and 232 Th are natural nuclear materials, unsuitable for use as nuclear fuel, since they are fissioned only by fast neutrons. But these isotopes can be used to produce artificial fissile nuclides
(233 U, 239 Pu), i.e. for the reproduction of secondary nuclear fuel. These nuclides are often called fertile isotopes.
At the present stage, nuclear energy is based on natural uranium, which consists of three isotopes:
1) 238 U; content – 99.2831%; half-life T1/2 =
4.5 10 9 years;
2) 235 U; content – 0.7115%; half-life T1/2 = 7.1 108 years;
3) 234 U; content – 0.0054%; Half-life T1/2 = 2.5 105 years.
By the way, the age of the Earth (approximately 6 billion years) is comparable to the half-life of 238 U.
Interestingly, 234 U is the product of one α decay of 238 U and two β decays of intermediate isotopes. This chain of isotopic transitions can be written in the following form:
238 U(α)234 Th(β,T1/2 =24 days)234 Pa(β,T1/2 = 6.7 hours)234 U.
All isotopes of uranium are radioactive, emit α particles with an energy of 4.5–4.8 MeV, and can also spontaneously fission with the emission of neutrons (for example, 13 n/s with 1 kg of 238 U).
The 235 U isotope is the only natural nuclear material that can share neutrons of any energy (including thermal neutrons) with the formation of an excess amount of fast neutrons. It is thanks to these excess neutrons that a fission chain reaction becomes possible. But in natural uranium the isotope 235 U is contained only at a level of 0.71%. Most currently operating power reactors operate on uranium enriched with the 235 U isotope to 2–5%. Fast reactors use 15–25% enriched uranium. Research reactors often use medium to high enrichment uranium (up to 90%). The IAEA currently recommends that member countries gradually convert their research reactors to fuel with no more than 20% enrichment. The critical mass of uranium enriched to 20% is 830 kg, and the theft of such an amount of uranium from research reactors is practically impossible.
Enriched uranium is uranium containing 235 U in an amount greater than its concentration in natural uranium. Uranium is distinguished:
1) low enriched – X 5 < 5%;
2) medium enriched – X 5 from 5 to 20%;
3) highly enriched – X 5 from 20 to 90%;
4) super-enriched (weapons grade) – X 5 > 90%.
When producing enriched uranium, depleted uranium is formed as a by-product, i.e. uranium with 235 U content below natural levels. Modern enrichment technologies are accompanied by the formation of depleted uranium, the content of 235 U in which is usually at the level of 0.2–0.3%.
The 235U content of natural uranium (0.71%) has not always been this way when considering geological time scales. The half-life of 235 U is approximately 6 times shorter than that of 238 U (0.7 109 years versus 4.5 109 years). Therefore, previously the enrichment of natural uranium was greater than 0.71%. At the uranium mine in Oklo (Gabon) in 1973, uranium was discovered with an abnormally low content of 235 U, only 0.44%. Previously, no deviation of the 235 U content from the standard value of 0.71% had ever been observed anywhere. Computational studies have shown that approximately 1.8 billion years ago, when the enrichment of natural uranium was about 3%, in the presence of a moderator, such as light water, a fission chain reaction, or natural nuclear reactor, arose inside the uranium ore and was maintained for approximately 600 thousand years. Oklo”, as a result of which 235 U burned up. According to calculations, the average thermal power of “Oklo” was 25 kW with a neutron flux of 4,108 n/cm2 s. The total energy production of Oklo over 600 thousand years amounted to 15 GW per year, which is equivalent to the energy production of LNPP for 2.5 years.
The main isotope of natural uranium, 238 U, upon capture of neutrons, turns into secondary nuclear fuel, the isotope 239 Pu, after two successive β decays:
238 U(n,γ)239 U(β,Т1/2 =23.5’)239 Np(β,Т1/2 =2.3 days)239 Pu.
The accumulation of the 233 U isotope occurs similarly when natural thorium is irradiated with neutrons. When neutrons are captured, 232 Th transforms into 233 U after two β decays:
232 Th(n,γ)233 Th(β,T1/2 =23.3’)233 Pa(β,T1/2 =27.4 days)233 U.
But in order to carry out these transformations in a nuclear reactor, primary nuclear fuel must be located there, i.e. isotope 235 U, capable of initiating a self-sustaining fission chain reaction, accompanied by the generation of excess neutrons, which can be used to produce secondary nuclear fuel in neutron capture reactions with fertile isotopes. The presence in the fuel of thermal power reactors of a large amount of the fertile isotope 238 U (95–97%) allows for partial reproduction of nuclear fuel.
The following types of nuclear fuel are used:
1) pure metals, metal alloys, intermetallic compounds;
2) ceramics (oxides, carbides, nitrides);
3) metal ceramics(cermet particles of metal fuel are dispersed in a ceramic matrix);
4) dispersed fuel (fuel microparticles in a protective shell are dispersed in an inert, for example graphite, matrix).
The main structural form of fuel in a nuclear reactor is the fuel element (fuel element). It consists of an active part, which contains fuel and breeding nuclear materials, and an outer hermetic shell. Typically, the shell is made of metal (stainless steels, zirconium alloys), and in spherical fuel rods of HTGR fuel microparticles are coated with layers of silicon carbide and pyrolytic carbon.
fixed fuel rods: 5–10 mm in diameter, 2.5–6 m in length, i.e. h/d 500. Typical number of fuel rods in a reactor: VVER-440 contains approximately 44,000 fuel rods, VVER-1000 - 48,000 fuel rods, RBMK-1000 - 61,000 fuel rods. Fuel rods are combined into fuel assemblies (FA): from several pieces to several hundred fuel rods in one FA. In fuel assemblies, fuel rods are strictly spaced, conditions are created for reliable heat removal from fuel rods and to compensate for the thermal expansion of their materials.
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