Centrifugal Separation - doe-hdbk-1113-98_reaffirm_2005

DOE-HDBK-1113-98

Radiological Safety Training for Uranium Facilities

Module 102 The Nuclear Fuel Cycle

Centrifugal Separation

Centrifugal separation is based on heavier compounds migrating to the

outside when spun at a high rate of speed.

The uranium left over from the enrichment process is mostly 238U, with a

reduced amount of 235U (usually 0.2% by weight). This byproduct is called

"depleted uranium" and has additional uses such as radiation shielding, armor

plating, and ammunition.

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.

4. Fabrication

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 following steps.

Uranium dioxide (UO2) is produced by reacting UF6 with water and then

with a hydroxide salt.