What types of nuclear reactors exist?

nuclear reactors can be classified in several different ways: depending on the type of nuclear reaction, used moderator material, coolant used, reactor generation, fuel phase, fuel type and use. Counting research reactors, thousands exist around the world and fall into many different categories. In this article I will go through the classification schemes of nuclear reactors one by one.

In this article, we only look at fission nuclear reactors, ie reactors that divide the cores rather than fusion reactors that connect them together. Fusion reactors are still highly experimental technologies in the early stages of development, while fission reactors have been used for over 60 years. Most reactors using fast neutrons fall into the category of fast breeding reactor, while most of the use of slow neutrons are called thermal reactors. Thermal reactions are the cheapest and most common, mainly because they can use natural, non -enchantment uranium. The neutrons in the heatThese reactors are referred to as "slow" because the reactor uses moderating material to slow neutrons from their natural speed when it is released from the broken atomic core, which is quite fast, closer to the speed and heat of the surrounding fuel medium. Fast neutron reactors are more expensive and require fuel to be more enriched, so it is less popular. On the other hand, they create more fuels than they consume, which makes them attractive for longer -term.

Moderal material is the second classification scheme for nuclear reactors. As mentioned earlier, only thermal nuclear reactors use moderators, so it only covers them. Graphite, heavy water and normal water are used as moderators. Graphite and heavy water reactors are more popular because these moderation materials thermizes neutrons better and ensure that natural uranium can be used and no enrichment is required.

Another classification scheme is based on generation. Generation I reactors were the first prototype reactors, usually one of the species. Generation II reactors have been made for commercial use and on the basis of standard designs. They started to be used in 50 years. Generation III reactors are more modern and are used at the end of the 90's. They are lighter and more efficient than previous generations. The latest generations, generation IV reactors, are currently under research and are not expected to be introduced until the end of 2020 or early 30 years. These reactors will be very economical and produce minimal waste.

Another type of classification is the fuel phase - liquid, solid or gas. The solid is the most typical. Along with the phase comes the type of fuel - uranium or thoria. These are the only two elements ready for the reactor available in considerable amounts.

The latest classification is based on use - for power plants, drive, nuclear fuel production (breeding reactors) or research reactors. Radioisotope thermoelectric generators (RTGs) are also sometimes thrown by nuclear reactors, although they are somewhat different. The X -ray generates energy from the disintegration of radioactive isotope.

And that's it. There are more specific ways to characterize nuclear reactors and numerous patterns at different stages of development, but the amount of written material on the types of nuclear reactor could probably fill a small library.