The series of events in which neutrons from split uranium nuclei lead to the splitting of more uranium nuclei is called a:

The concentration of the lighter isotope of uranium, uranium-235, is very low in nature relative to the abundance of the heavier uranium-238. In most modern reactors, the abundance of uranium-235 in the fuel needs to be enriched by a factor of:

If a nuclear reactor were to have a meltdown, radioactive materials could escape in the form of gases from the reactor into the atmosphere and harm humans and the environment. One safety system that might be able to prevent such an escape is a:

Plutonium is a radioactive material, exposure to which is hazardous to human health, and is one of the few materials that can be used to make a nuclear weapon. The time it takes for half of any initial quantity of plutonium to decay into stable non-radioactive products is roughly:

What substance is used as a moderator to scatter and slow down neutrons just enough to increase their capture by Uranium and raise the rate of fission?