F Canyon was constructed in the early 1950s and began operations in 1954. The building is called a canyon because of its long, narrow shape. All work in the canyon is remotely controlled, and employees are further protected from radiation by thick concrete walls. Equipment and piping are maintained using overhead bridge cranes. Irradiated fuel slugs and rods enter the canyon by rail on shielded cask cars.
Nuclear material can also enter the canyon as solutions, or be directly fed to the dissolvers.
Plutonium and uranium are separated and transferred to various processing sections to remove contaminants and purify the products. Samples from each treatment step are analyzed to ensure the safety of the process. Pu-238 is used in power systems for deep space exploration. Processing of spent fuels from SRS reactors was interrupted in 1988 due to a decision to halt liquid uranium shipments. While recovery was no longer needed, there remained a large inventory of highly enriched uranium fuels and solutions in various stages of the SRS process.