Question

Wherevdo the neutrons for nuear fssion come from ?

Answer 1

Answer:

While the reactor is running, the vast majority of neutrons are produced by the fission of U-235 in our fuel.

Answer 2

In order to initiate most fission reactions, an atom is bombarded by a neutron to produce an unstable isotope, which undergoes fission. When neutrons are released during the fission process, they can initiate a chain reaction of continuous fission which sustains itself.