Some of the terms used in this factsheet are defined in IEER's on-line glossary . Since the end of the Cold War, though, operations at SRS have been predominately aimed at trying to stabilize the waste and contamination created by past reprocessing and at stabilizing a few hundred tons of radioactive material, most of which has been stored on-site since the 1980's. Most of this material is already at SRS, and the remainder is scheduled to arrive there during the next 35 years. Background Reactors are fueled by a mixture of uranium.
Fuel is comprised of enriched uranium surrounded by, or clad with, a metal.
The cladding used at SRS was aluminum. Stainless steel and other metals are often used elsewhere. U-235 decays inside a reactor. This sets off a chain reaction during which a very large number of U-235 atoms split apart in a very short time. After a while, operators of the reactor stop the chain reaction by inserting control rods which absorb the neutrons coming off the decaying and splitting U-235, and then they remove the fuel from the reactor.