Question

which type of neutron is used for the process of nuclear fission and how we can stop it

Answer 1

In nuclear fission two hydrogen atoms combine to form a single helium atom which generates lot of heat. It takes place on the surface of the sun.
There is no way to stop it.

Answer 2

In nuclear fission two hydrogen atoms combine to form a single helium atom which generates lot of heat. It takes place on the surface of the sun.

There is no way to stop it.