The article talks about what a fuel rod is, why it is needed, where it is used, how it is created and whether there are reactors that do not use a fuel rod.
Atomic era
Probably the youngest energy industry is nuclear. It was only at the end of the 19th century that scientists were able to partially understand what radioactivity, radioactive decay are and what substances possess these properties. And for many, this knowledge cost their lives, since the detrimental effect of radiation on living organisms has long remained unknown.
Much later, radioactive materials found application both in civilian life and in military life. Currently, all developed countries have their own nuclear weapons and nuclear power plants, which allow a large amount of energy to be obtained regardless of fossil fuels or natural resources such as water (we are talking about hydropower plants).
TVEL is ...
But in order to build a nuclear reactor for the production of electricity or other purposes, first you need to make the appropriate fuel, because natural uranium, although it has radioactivity, but its energy is not enough. Therefore, in most types of reactors, fuel based on enriched uranium is used, and it, in turn, is loaded into special devices called TVEL. A fuel rod is a special device that is part of a nuclear reactor and contains nuclear fuel. We will analyze their design and type of fuel in more detail.
Design
Depending on the type of reactor, some parameters of the fuel elements may vary, but their general design and device principle are the same. In simple terms, a fuel rod is a hollow tube made of an alloy of zirconium with some other metals, in which uranium dioxide fuel pellets are installed.
Fuel
Uranium is the most “running” radioactive material; on its basis, many other isotopes are produced that are used both in industry and in weapons. Its extraction is not much different from the extraction of coal, and in its natural state it is absolutely safe for people. So the stories about uranium mines, to which life-sentenced prisoners are exiled, are nothing more than a myth. A person is more likely to die from a lack of sunlight and hard work in a mine than from radiation sickness.
Mining uranium is very simple - the rocks are broken up by explosions, after which it is delivered to the surface where it is sorted and further processed. The uranium enrichment process can be carried out in various ways, but in Russia this is done using gas centrifuges. First, uranium is transferred to a gaseous state, after which the gas in centrifuges is separated by centrifugal force and the desired isotopes are separated. After that, they are converted into uranium dioxide, pressed into tablets and loaded into a fuel rod. This is the most common way to produce fuel for fuel elements.
Application
The number of fuel rods in a reactor depends on its size, type and power. After manufacturing, they are loaded into the reactor, where the nuclear decay reaction begins, as a result of which a powerful release of a huge amount of heat occurs, which serves as a source of energy. Also, the power of the reactor can be controlled by the number of fuel elements in the working area. From time to time, during operation, they are replaced with new ones, with "fresh" tablets of uranium dioxide. So now we know what TVEL means, how they are made and why they are needed at all. However, not all nuclear reactors need such elements, and these are RTGs.
RTG
A radioisotope thermoelectric generator is a device that in its principle is similar to atomic reactors, but their process is based not on a chain reaction of atom decay, but on a thermal one. Simply put, this is a large installation that generates a lot of heat with a radioactive substance, which, in turn, is converted directly into electricity. Unlike nuclear reactors, RTGs do not have moving parts, are more reliable, compact and durable. But at the same time they have much lower efficiency.
They were used mainly in those conditions where it is impossible to obtain energy in other ways, or these methods are very difficult. In the years of the USSR, RTGs were supplied to research and meteorological stations of the Far North, coastal lighthouses, sea beacons, etc.
Currently, their service life has expired, but some of them still remain in their original locations and are often not even guarded. As a result of this, accidents occur, for example, several non-ferrous metal hunters tried to dismantle such installations and received strong radiation, and in Georgia local residents used them as heat sources and also suffered from radiation sickness.
So now we know the structure of the fuel elements and have analyzed their definition. The fuel elements are important parts of the reactor, work without which is impossible.