The most commonly used radioactive fuel is Plutonium (Pu) 238, which is alpha active and produces a useful amount of thermal energy, without the need for much shielding. This material is produced from Neptunium 237, which is separated out from spent reactor fuel. The Pu238 is assembled with a thermocouple array to produce a small amount of electricity, and is widely used in satellites if solar panels are not viable. Pu 238 has a half life of 87 years, so can power applications where the mission lasts a long duration.
Other materials have been used, amongst them Strontium 90, but Pu238 is now the favourite. Wikipedia has entries giving more information-see 'Nuclear Fuel' section 8
Every element above a certain point is radioactive, like plutonium, radon, uranium, etc., but some isotopes of small elements can be radioactive as well. Like C14 which is used for carbon dating.
Uranium and plutonium
Uranium
Radium
Usually Uranium 235 but sometimes Plutonium 239
Uranium 235 or Plutonium 239
This is the purpose of nuclear power plants and is very successfully done, 104 reactors in the US for example.
The used fuel in a nuclear power plant is the nuclear fuel being discharged from the nuclear reactor after being irradiated during reactor operation. It is usually composed of trans-uranium heavy elements, a wide variety of fission products (that resulted from the nuclear fission processes in the nuclear reactor) and products of radioactive decay (produced before and after fuel discharge from the nuclear reactor).
Nuclear energy is produced by fission of new fuel, which is only very slightly radioactive to start with (it is safe to handle unprotected). It becomes radioactive during the reactor's operation, and at the end of life the radioactivity of the fuel contributes some 5% or so of the output heat, the rest is due to fission directly. There are some uses for radioactive isotopes to produce electricity directly but these are only used in satellites for small instrument type supplies.
Uranium is a radioactive element used to fuel nuclear reactors. It is a nuclear fuel.
Radioactive elements used for fuel include Plutonium -239 Uranium-235 and uanium-233.
Normally Uranium but some other radioactive materials are occasionally used.
Uranium
Uranium is a solid metal, natural chemical element with 3 natural isotopes, radioactive, with the atomic number 92, used as fuel in nuclear reactors and nuclear weapons.
Uranium is a natural chemical element, metal, solid, toxic, radioactive, reactive, very dense, used as fuel in nuclear reactors, used in nuclear bombs, used in alloys for tankks armors, etc.
Uranium is the most used nuclear fuel. Plutonium can also be used, but it has to be separated from used uranium fuel
Uranium
One of the radioactive elements used for nuclear energy is 235U92, commonly stated as U-235.
We can use plutonium in nuclear fission devices.
We know that plutonium is radioactive, highly toxic and is fissionable (capable of use in a nuclear weapon).
The fuel rods are of uranium dioxide, with the uranium enriched to about 5% U-235