Nuclear fuels are all materials that have been adapted for use in the production of nuclear energy .
The material itself (whether for fusion or fission) can be mentioned as well as the bundles of nuclear fuel already produced that, in a solid, shared and chemically inert form, can be used later depending on the needs.
What are nuclear fuels?
Nuclear fuel refers to a material that through fission or fusion of nuclei can produce or release energy , being the way of obtaining energy from the division or by the collision of the nuclei of an atom.
This class of fuel must be composed of fissile elements, that is to say that the nucleus of the element must be capable of reacting with free neutrons of any kind of energy, undergoing fission ; The most widely used fissile element in nuclear fuel is uranium .
Uranium allows to generate controlled chain reactions inside the nuclear reactors that are in the power plants. The isotope most used in nuclear fission is Uranium 235 . Plutonium is another of the radioactive metals used as nuclear fuel . Both uranium and plutonium react through nuclear fission or fusion, releasing thermal energy .
Nuclear energy has gained acceptance in recent years and its applications are diverse; being in a controlled environment it is fairly clean (compared to others) but if there are nuclear failures or accidents, the disaster is very high.
How are nuclear fuels formed?
Uranium is an element found in nature . It is made up of three different isotopes: 238U, 235U and 234U .
To use uranium in nuclear reactors, a series of physical and chemical processes must be carried out. In this way, the element passes from its natural form (mineral) to the ceramic oxide pellets that are placed in the core of the reactor.
First, the uranium is mined from the ground, crushed and processed. It is usually dissolved with sulfuric acid and a yellow cake called “yellowcake” is obtained . The uranium is then converted to UF6 for further enrichment to isotope 235, before being converted back to uranium oxide.
Power generation by nuclear fuels
To harness nuclear energy, energy is obtained from the nuclear bonds of the atom, in the form of heat . The production of energy from nuclear fuels requires nuclear fission or fusion to occur.
Fission is radioactive decay in which the nucleus of an atom splits into smaller or lighter nuclei. Fission produces free photons and neutrons , releasing large amounts of energy.
On the other hand, fusion is a reaction where two nuclei or more than one atom collide at very fast speeds, join together and form a new atomic nucleus .
Nuclear power plants are responsible for obtaining the energy released by these nuclear reactions. Among the elements that make up these facilities is a nuclear reactor , which is the component where the reactions occur. The heat energy drives turbines and the latter generate electricity.
The power plants that have been installed today use nuclear fission, fusion is still in the experimental period .
Types of nuclear fuels
The classification of nuclear fuels is given by the type of reactor, whether it is fission or fusion.
FUELS IN FISSION REACTORS :
They can be liquid, metallic, ceramic or based on oxides (such as mixed oxides or uranium dioxide). Other forms of fuels include powdered uranium dioxide, PWR (Pressurized Water Reactor) fuel, BWR (Boiling Water Reactor), and CANDU .
FUELS IN FUSION REACTORS :
There is deuterium and tritium. They are usually divided into first, second and third generation fuels . The first group are the easiest to smelt because they have low charges on the nuclei, tritium and deuterium are included here .
Second generation elements generate fewer neutrons and need confinement temperatures . Those of the third generation produce only charged particles in the primary reactions.
What are nuclear fuels used for?
Nuclear technology is the name given to the set of techniques that uses reactions between atomic nuclei.
- GENERATE ENERGY
- Reactors are the most widely used class of technology, because they control the reactions in nuclear power plants . In these, the heat generated in the fission is transmitted to a working fluid, which in turn passes to some turbines so that the electric generators are mobilized.
- MEDICINE and RESEARCH
- On the other hand, gamma rays and X-rays are another kind of technology applied in different fields and for various purposes. The medical field has benefited from this technology for the diagnosis and treatment of certain pathologies that require radiation.
- Nuclear weapons , devices that release enormous amounts of energy based on small amounts of matter. Unfortunately, these weapons have devastating effects and some have been conceived as weapons of mass destruction .