College of Engineering
University of Wisconsin - Madison
UWNR

University of Wisconsin Nuclear Reactor Tour

UWNR Fuel


The fuel we use at the UWNR is Uranium. Our fuel contains Uranium-235 and Uranium-238. Uranium  is mined out of the ground and is about 1% U-235 and 99% U-238. The Uranium in our fuel is processed and enriched to have a higher concentration of U-235. Each fuel element is about a meter long, which includes a top and bottom end fitting. Inside the center of the fuel pin is a mixture of Uranium, Zirconium, Erbium, and Hydrogen. On either end of this fuel section is a plug of graphite which helps to reflect neutrons back toward the fuel, thereby increasing the efficiency of the reactor. Four of these fuel pins are put together to form a fuel bundle. A fuel bundle has a square bottom fitting so that it can be positioned in the grid box. It also has a top fitting which has a handle on it so the bundle can moved around as needed for different tests and experiments. There are several dozen fuel bundles in the reactor arranged in a nearly square shaped pattern with the control elemets mized in.

On to the next part of the tour- the control elements.

This is how the fission process works.

Back to the reactor.