Long-lived fission product

Long-lived fission product‏‎

Long-lived fission products (LLFPs) are nuclear fission products that have a long half-life, typically longer than 200,000 years. They are produced in a nuclear reactor when a neutron strikes the nucleus of a nuclear fuel atom, causing it to split into two smaller atoms, known as fission products. Some of these fission products are stable, but many are radioactive and decay over time, releasing radiation.

Types of Long-lived Fission Products

There are several types of LLFPs, each with its own unique properties and decay patterns. These include:

• Technetium-99: With a half-life of 211,000 years, Technetium-99 is one of the most common LLFPs. It is produced in significant quantities in nuclear reactors and is a major contributor to the long-term radioactivity of spent nuclear fuel.

• Iodine-129: Iodine-129 has a half-life of 15.7 million years, making it one of the longest-lived fission products. It is produced in smaller quantities than Technetium-99, but its long half-life means that it remains radioactive for a very long time.

• Plutonium-239: Plutonium-239 is not a fission product, but a transuranic waste product. It has a half-life of 24,000 years and is produced in nuclear reactors from the absorption of a neutron by Uranium-238.

Management and Disposal

The management and disposal of LLFPs is a significant challenge for the nuclear power industry. Due to their long half-lives, these materials remain radioactive for hundreds of thousands to millions of years, posing a potential risk to human health and the environment.

Currently, the most common method of managing LLFPs is through geological disposal, where the waste is buried deep underground in a specially designed repository. However, this method is not without its challenges, as it requires careful site selection and long-term monitoring to ensure the waste remains contained.

Another potential method for managing LLFPs is transmutation, where the waste is subjected to a process that changes its atomic structure, effectively turning it into a different, less hazardous material. However, this method is still in the experimental stages and is not yet used on a large scale.

See Also

• Nuclear fission
• Nuclear waste
• Radioactive decay
• Half-life