Which statement best describes breeder reactors? 

A)  The use of a breeder reactor would not extend the supplies of uranium in the world. 
B)  If a breeder reactor's safety system failed, the reactor would be fine. 
C)  Many experimental breeder reactors are safe. 
D)  A breeder reactor would generate more fuel than it would consume.

Breeder reactors are designed to generate more fuel than they consume. They accomplish this by using a fuel (usually uranium-238) that is not very reactive on its own. The reactor first converts this fuel into a more reactive fuel (usually plutonium-239) and then uses that to produce energy. This process creates more fuel than it uses, making it a potentially sustainable energy source. However, there are safety concerns associated with breeder reactors, particularly with regard to the handling and disposal of the plutonium produced.