Radiological Safety Traning for Uranium Facilities
Module 102 - The Nuclear Fuel Cycle
Centrifugal separation is based on heavier compounds migrating to the outside
when spun at a high rate of speed.
The uranium le ft over from the e nrichment pro cess is mostly
U, with a reduced amount
of 235U (usually 0.2% by weight). This byproduct is called "depleted uranium" and has
During World War II, uranium work was secret and code names were used for the
different forms of uranium. Natural uranium was named "Tuballoy," a name that grew
out of a cover story that the Allies were investigating alloys for high-quality tubing.
Highly enriched uranium was then named "Oralloy" for "Oak Ridge Alloy," sometimes
abbreviated to "Oy." Depleted uranium was once called depletalloy, but more commonly
was called "D-38" since it consists mostly of 238U. These historical names are sometimes
still used within the DOE complex.
The last step in the nuclear fuel cycle is changing the enriched uranium into an
appropriate form for fabrication. The fabrication process differs depending on the
application. For fabrication of fuel elements, the process generally includes the
Uranium dioxide (UO2) is produced by reacting UF6 with water and then with a
The resulting precipitate is dried to form "orange oxide," which is reduced with
hydrogen to form UO2 powder.
The UO2 powder is compacted into cylindrical pellets that are loaded into thin-
walled tubes made of either stainless steel or an alloy of zirconium called