Reiityosuus

Reiityosuus, also known as the "recovery ratio" or "recovery factor," is a term used in nuclear engineering and radiochemistry to describe the proportion of fission products that are recovered from spent nuclear fuel. It is a critical parameter in the design and operation of nuclear fuel cycles, particularly in the context of nuclear reprocessing and recycling.

The recovery ratio is calculated as the ratio of the mass of the recovered fission products to the mass of the fission products present in the spent fuel before reprocessing. A higher recovery ratio indicates a more efficient reprocessing system, as it means that a larger fraction of the valuable fission products is being successfully extracted and separated from the spent fuel.

The recovery ratio is influenced by several factors, including the type of reprocessing method used, the chemical properties of the fission products, and the operating conditions of the reprocessing plant. Common reprocessing methods include the PUREX (Plutonium Uranium Extraction) process, which is widely used in commercial nuclear power plants, and advanced reprocessing techniques such as the GANEX (Group Actinide Extraction) process.

Improving the recovery ratio is essential for the economic viability of nuclear fuel cycles, as it directly affects the amount of fissile material that can be recycled and reused in nuclear reactors. Additionally, a higher recovery ratio can help reduce the volume and radiotoxicity of nuclear waste, contributing to the long-term sustainability of nuclear energy.