Thorium-232

Thorium-232

Decay chain of Thorium-232

Thorium-232 is a naturally occurring radioactive isotope of the element thorium. It is the most stable isotope of thorium, with a half-life of approximately 14 billion years, which is longer than the age of the Earth. Thorium-232 is a fertile material, meaning it can be converted into a fissile material, such as uranium-233, through the process of neutron capture and subsequent beta decay.

Properties

Thorium-232 is a heavy metal with an atomic number of 90 and an atomic mass of 232.0381 u. It is a member of the actinide series in the periodic table. Thorium is a silvery metal that tarnishes black when exposed to air, forming thorium dioxide (ThO_). It is moderately hard, malleable, and has a high melting point of 1750 °C.

Decay Chain

Thorium-232 undergoes radioactive decay through a series of alpha and beta decays, eventually leading to the stable isotope lead-208. This decay series is known as the thorium series or the 4n decay chain. The decay chain of thorium-232 includes several intermediate radioactive isotopes, such as radium-228, actinium-228, and thorium-228.

Applications

Thorium-232 has potential applications in nuclear energy. It can be used in thorium fuel cycles to breed uranium-233, which is a fissile material that can be used in nuclear reactors. This process has the potential to provide a more abundant and safer source of nuclear fuel compared to traditional uranium-based fuel cycles.

Safety and Environmental Impact

Thorium-232 is radioactive and must be handled with care to avoid exposure. It poses a risk of radiation exposure, particularly through inhalation or ingestion of dust containing thorium. However, thorium is less hazardous than other radioactive materials, such as plutonium.

The mining and processing of thorium can lead to environmental contamination if not managed properly. It is important to follow strict safety protocols to minimize the release of radioactive materials into the environment.

Related pages

• Thorium
• Uranium-233
• Nuclear fuel cycle
• Radioactive decay
• Actinide series