Uranium
Uranium is a heavy metal with the symbol U and atomic number 92. It is part of the actinide series on the periodic table and is widely known for its use in nuclear power and nuclear weapons.
Natural Occurrence and Mining
Uranium is primarily found in the form of the isotopes uranium-238 and uranium-235. Uranium-238, which comprises over 99% of natural uranium, is not fissile but can be transformed into fissile plutonium-239 in a nuclear reactor. Uranium-235, on the other hand, is naturally fissile and plays a crucial role in nuclear reactors and atomic bombs.
Uranium is extracted through uranium mining. The largest producers of uranium include Kazakhstan, Canada, and Australia. After extraction, uranium undergoes a series of processes in order to be converted into a form suitable for use in nuclear fuel.
Enrichment and Depletion
In its natural state, uranium contains only about 0.7% of uranium-235, which is not sufficient for most nuclear reactors. Therefore, uranium must be enriched, which involves increasing the percentage of uranium-235. This process results in enriched uranium that can sustain a chain reaction in a nuclear reactor.
The byproduct of this process is depleted uranium, which contains a lower concentration of uranium-235. Despite its reduced radioactivity, depleted uranium is dense and is used in military applications such as armor-piercing munitions.
Uses
Uranium's most significant use is as a fuel in nuclear reactors. In a reactor, uranium-235 undergoes fission, releasing a large amount of heat. This heat is used to produce steam, which drives turbines to generate electricity.
In addition, uranium is used in research reactors and in the production of radioisotopes for medical and industrial purposes. Uranium glass is a decorative glass containing uranium, which fluoresces under ultraviolet light.
Chemical Compounds
Uranium forms several compounds, the most notable of which is uranium hexafluoride. This compound is used in the uranium enrichment process. Other compounds include uranium dioxide and uranium trioxide, which are used in fuel pellets for reactors.
Environmental and Health Concerns
Handling and processing uranium pose environmental and health risks due to its radioactivity. Uranium tailings from mining are a significant environmental concern as they remain radioactive for thousands of years. Strict regulations are in place to manage and store uranium waste safely.