tuumakütusena

Tuumakütusena refers to nuclear fuel in Estonian. Nuclear fuel is a material that contains fissile isotopes and is used in nuclear reactors to sustain a nuclear chain reaction. The most common fissile isotope used in nuclear power plants is Uranium-235 (U-235).

Natural uranium, mined from the Earth, is primarily composed of Uranium-238 (U-238) and a small percentage of U-235. For use in most light-water reactors, natural uranium is enriched to increase the concentration of U-235. This enriched uranium is then typically fabricated into ceramic pellets, which are loaded into long metal tubes called fuel rods. These fuel rods are then assembled into fuel assemblies, which are placed within the reactor core.

When a neutron strikes a U-235 atom, it can cause the atom to split, or fission, releasing a significant amount of energy in the form of heat, as well as more neutrons. These newly released neutrons can then go on to cause further fissions, creating a self-sustaining chain reaction. The heat generated by this process is used to produce steam, which drives turbines to generate electricity.

Besides uranium, other materials can be used as nuclear fuel, such as plutonium and thorium. However, uranium remains the most widely utilized fuel in current nuclear power generation worldwide. The management and disposal of spent nuclear fuel, which is radioactive and hazardous, is a significant aspect of the nuclear fuel cycle.