No. Our reactors are fission reactors. We haven't yet mastered fusion reactors for power.
Nuclear fusion reactors do not exist yet as we don't know how to build them. All nuclear reactors are nuclear fission reactors.
In test reactors.
Well, fusion bombs are, but fusion reactors should not be (if we can build them).
Please elaborate on "they" as no comparison can be given otherwise. Do you mean?: "How is nuclear fusion different from regular nuclear reactors (nuclear fission?)"
Mostly in test reactors, though some operational reactors (though only a small number) are in service. Also, if you have ever heard of an H-bomb, or a hydrogen bomb, that is nuclear fusion.
Mostly power plants operating with fission reactors. Also experiments with nuclear fusion, and nuclear weapons
Well, as nuclear reactors are nuclear reactors, nuclear reactors are not used inside nuclear reactors.
nuclear fusion
Nuclear fusion is used only in experimental installations.
Today these installations are not surely controlled.
Mostly power plants operating with fission reactors. Also experiments with nuclear fusion, and nuclear weapons
Well, scientists have been researching fusion reactors for over 50 years, but nuclear fusion is much more difficult to achieve than nuclear fission, which is what current nuclear power technology is based on. There are many reasons for this, but while there have been tests and advancements in the field, scientists have yet to a) create a sustainable and stable nuclear fusion reaction and b) create a reaction that has a greater output than input.