blast wave overpressure
Most of the energy release is blast.
Elements = atoms If you "cut" an element into pieces, essentially split the atom, you release its energy. This is called fission, nuclear fission to be precise, and leads to a nuclear detonation. Depending on the atom you split, there will be a release of energy and radiation.
A nuclear detonation creates a severe environment including blast, thermal pulse, neutrons, x- and gamma-rays, radiation, electromagnetic pulse (EMP), and ionization of the upper atmosphere. Depending upon the environment in which the nuclear de-vice is detonated, blast effects are manifested as ground shock, water shock, "blueout," cratering, and large amounts of dust and radioactive fallout.
Nuclear fusion ======================== It's the same atomic process responsible for the great release of energy during the detonation of a hydrogen bomb, except that it goes on continuously in the core of the sun.
When a nuclear power plant explodes the largest worry is that the fuel source, like Uranium or Plutonium, will be released. This in turn would release huge amounts of radiation into the surrounding area.
Bleach - 2004 Kariya Countdown to the Detonation 5-14 was released on: USA: 29 November 2006
Stars Earn Stripes - 2012 Rapid Detonation - 1.3 was released on: USA: 27 August 2012
First and foremost, it is impossible for a nuclear power plant to explode. i.e. to go nuclear, because it is impossible for it to stay in prompt critical geometry long enough to consume the fuel for a runaway reaction to occur. Period. Not possible. Even if a terrorist organization infiltrated the facility and blew it up, that would be a chemical explosion, not a nuclear explosion. Yes, there would be release of radioactive materials to the environment, but it would not be a nuclear detonation as from a nuclear bomb. Get your heads straight around that. Its just not possible. The geometry is all wrong.
Nuclear reactions are more "explosive", i.e. energetic, because they depend on the release of binding energy, which is also called the strong force, or the strong interaction. (The four fundamental forces in nature are the strong force, the electromagnetic force, the weak force, and gravity.) Contrast this with chemical reactions, such as the detonation of TNT, and you have many, many more orders of magnitude per unit of source mass with nuclear.
Unbelievably rapid resistive heating of air as millions of amperes of current flows through it. The air becomes nearly as hot as the core of a nuclear bomb and expands supersonically, forming a shock wave indistinguishable from that of the detonation of explosives.
Nuclear fission
Well, basic explosives really. Timers or detonation triggers. (The D.T.'s were for putting in the tip of the warhead, for detonation.). Sometimes gunpowder, sometimes gasoline. But for the more destructive ones, atoms that are split and awaiting energy release.