Of course, we don’t have to stick with fission at all. At least not long term. Nuclear fusion, in which molecules are combined into a new element using immense heat and pressure, is safer, overwhelmingly more powerful, clean and harmless to the environment, and could provide power in enough abundance to launch mankind into the kind of future only dreamed of on The Jetsons. Sadly, at this moment it’s not easy to sustain net positive (meaning we get more energy out of the reaction than we have to put in to trigger it) fusion reactions long enough to be commercially viable.
There’s an old adage commenting on the long, long road fusion has already traveled and how far it still has before we start rolling it out: “nuclear fusion is the power source of the future, and always will be.” It’s funny and a bit depressing, given the enormous potential that always seems to be just one breakthrough away. But we know fusion, the Holy Grail of clean energy research, works. We need only look up at the stars, which exist because of fusion. So technically, since none of us would exist without the sun, you do too.