uraniumi238

Uranium-238, denoted as 238U or U-238, is the most common isotope of uranium, making up about 99.27% of naturally occurring uranium. It is a radioactive element with a very long half-life of approximately 4.468 billion years. This long half-life means that it decays very slowly.

The decay of uranium-238 follows a series of alpha and beta decays, ultimately leading to stable lead-206. This decay chain is important in radiometric dating, particularly for very old rocks and the Earth itself. While uranium-238 is not fissile, meaning it cannot sustain a nuclear chain reaction on its own in a typical reactor, it is fertile. This means that under neutron bombardment, it can absorb a neutron and undergo a series of transformations to become plutonium-239, which is fissile. This property is utilized in some nuclear reactor designs.

Uranium-238 is extracted from uranium ore, which is found in various deposits around the world. After mining and milling, the uranium is typically converted into a form suitable for enrichment or further processing. Due to its natural abundance and its role in the nuclear fuel cycle, uranium-238 is a significant element in the context of nuclear energy and nuclear weapons production. Its presence is also a factor in the natural radiation background of certain environments.