Yes
In an atom you have protons and neutrons in the nucleus. If you have a large nucleus w a high number of protons you have a lot of neutrons. Neutrons must be touching a proton so that they don’t go through beta minus decay. But when atoms get bigger the strong force that keeps the protons together gets too far apart. A neutron has to be touching a proton for it to be stable. When the nucleus size increases there is a too high of ratio of neutrons to protons and the neutrons go through beta minus decay due to the weak force.
If you have a small nucleus like helium you have two protons and two neutrons and the ratio is stable so in extremely high pressures and temperatures like on the sun those particles go through fusion.
Uranium has a large nucleus and the ratio of neutrons to protons is unstable and it will therefore go through fission.