It is in the ‘Nuclear fission’ where the Uranium is used, this starts off the process for nuclear power to be generated. ‘Nuclear fission is the process of atoms splitting’, so when a heavy nucleus such as Uranium splits into two smaller, lighter nuclei. In this reaction, the ‘strong nuclear force’ which is the attractive force, is acting on the ‘electrostatic force’ which is the repulsive force, these can be knocked out of balance on each other when they gain the energy from either a photon or a neutron. The two forces are affected by the gain of this other element and will try to act on each other to regain the state in which they were in, but in nuclear fission the ‘electrostatic force’ will gain more power than the ‘nuclear force’, therefore causing it to repel and for the nucleus to split apart, also releasing energy as it does so.To make this slightly easier to understand, imagine a load of marbles in a rough circle shape on a flat tabletop (this is going to be representing the original atoms nucleus, where all the forcing are acting the same on one another and are equal, so all the marbles/atoms are stable). ‘What if I were to then throw or roll another marble into this group of stable marbles?’ All the marbles would spread apart and move out into the space around them, this marble that is being rolled into them is acting as the photon or neutron that is being gained in the nucleus. This is unbalancing the forces and causing the atoms to all move around as they react to the change that is taking place, but seeing as all the marbles move out, and away from each other shows to us that the repelling force has gained more control, as the attractive force wasn’t able to keep them all together, and this is exactly what happens in nuclear fission.