For most of my life I have considered nuclear energy the best source of energy available. I still do. It is relatively compact, powerful, and abundant, to some extent. Once we learn how to use nuclear waste to generate electricity, we may have an energy source that will last us virtually forever.
There are and will be various types of reactors and nuclear energy systems that are being used and might be used in the future. The first type of reactor is the light-water reactor. The safest ones use superheated steam created by water that flows through the fuel rod bundles which heat a second source of water that is heated to above boiling to turn turbines connected to the generators. They are used around the world to generate over 300 gigawatts of electricity annually. Included in light-water reactors are the boiling water reactors that use one source of water which flows through the fuel core and becomes superheated. The water that flows by the turbines is radioactive and is dangerous if it leaks from the steam pipes.
The reactors are called light-water because they use regular water as opposed to the heavy-water reactors that use deuterium and are more expensive. Most of the reactors used around the world are light-water reactors with France receiving over 70% of its electricity from them and most of the submarines in our Navy and the aircraft carriers use the reactors too since they don't have to be refueled for years.
In the future, there may be various types of reactors that will be safer, more efficient, and at times more powerful even when they are smaller than existing reactors. One such reactor is the injection reactor. It uses a charged particle beam system to accelerate the nuclear decay in the fuel tubes to emit positive, negative, and neutrally charged particles. The positive and negative ones are cyceled through the reactor to maintain the beams, used by appliances, and provide particle field protection to prevent the leakage of radioactivity. The neutrons are absorbed by the moderating target. Water or gas is injected through the fuel tubes too to cool them and to create steam that runs the regular electrical generators. This type of reactor will be light, powerful, and safer since it relies on automatic safety systems to control it. If such a reactor is used in a car, it will be no larger than the standard engine but able to generate about as much energy as a fighter plane can generate, if needed. If there is an accident, the moderating material will be slammed into the fuel tubes to shut down the chain reaction immediately. Spaceplanes will use the reactor to allow them to fly to various planets and moons in the solar system and beyond.
One type of reactor that will use the injection reactor to initiate a chain reaction will be the fission/fusion reactor. It was first designed in 1977 and hasn't changed much since. The charged particles would turn hydrogen gas into heavy hydrogen, be used by particle beams to superheat the heavy hydrogen, and form electromagnetic compression fields that would cause the hydrogen to fuse into helium and liberate energy in the form of a plasma that would be circulated magnetically past steam pipes that would produce steam to run turbo-generators. In theory, some of the electricity generate would be used to circulate and magnetically contain the plasma until it is too cool to be of use. Then it will be vented so that more plasma can be produced. Once the reactor generates more power than it requires to initiate the reaction, it will become efficient.
Nuclear waste will be processed conventionally and also in a reactor called Red Rover. Like the game, particles from one side of the reaction chamber will pass from the highly radioactive side to the non-radioactive side. Water or gas will pass between the sides to cool the reactor and generate steam for the turbo-generators. Once the other side becomes more radioactive than the original side, the flow of particles will reverse. The alteration will continue until both sides are either minimally radioactive or non-radioactive. The waste should be much easier to store or dispose of.
A similar reactor is called the garbage reactor. It will use radioactive waste to turn solid waste into fuel temporarily. A plasma will be generated to incinerate the waste and liberate the particles that will cause a chain reaction and heat that will turn gas or water into steam for the turbo-generators. Garbage reactors will take care of nuclear and solid waste.
A hybrid reactor will be the electromagnetic field reactor. It will use the nuclear fuel to generate a circulating particle field that will tap the electromagnetic fields of the earth and generate electricity. As long as there are energy fields, the reactor should work.
Further in the future, once hyperlight physics becomes a reality, nuclear fuel will be created in a nuclear laboratory. A massive transuranic element that is normally stable will be produced by a blending process so that all the atoms are stable and not just a minimal amount that are stable only for a split second. it could be element 137 that will be stable normally and a nuclear fuel when exposed to either a charged particle beam or charged particle fields that will cause particles to be emitted. Once the beam or field is switched off, the fuel will once again become so stable that you could hold it in your hand once it warms us again and not be harmed by radioactivity.
If hyperlight physics becomes a reality, it may be possible to create a hyperlight-speed reactor that could produce a hyperlight-speed chain reaction that is more powerful than what a regular reactor can produce. Since according to hyperlight physics, when a hyper accelerated particle comes in contact with an unaccelerated particle, the hyperaccelerated one will cause the slower one to try to accelerate. Theoretically, less energy would be required to generate electricity and any type of material could become fuel.
As long as a plasma can be produced, solid waste can be incinerated. As long as the particles of a material can be made radioactive, virtually anything could become nuclear fuel. In the movie "Back To the Future: Part Two," Dr. Brown was seen placing waste into a fusion reactor. That will be feasible in the future. But most likely, it would be a garbage reactor that will use garbage to generate more energy. If a material can be broken down into particles, those particles can be used by appliances and generate heat as they collide with other particles. Any waste material could be stored for disposal if it is solid or become exhaust.
The injection reactor may become the first reactor sold to the public for everyday use. Once the price goes down and safety measures are taken to make the reactor totally safe, nuclear energy will become the energy source of choice until we learn how to tap the electromagnetic fields of the earth to generate virtually limitless inexpensive electricity. But for general use, nuclear power will be what most people will choose to use once it is known as our friend and not our enemy.