Chemistry can be differentiated into two main branches: nuclear chemistry and electronic chemistry, which derives from atoms and their parts: the nucleus and a cloud of electrons. Nuclear chemistry studies the nucleus by protons and neutrons, the variation in the number of neutrons in an atom can give rise to the isotopes. Radioisotopes are radioactive isotopes since they have an unstable atomic nucleus and emit energy and particles when they are transformed into a more stable different isotope.

The radioactive energy is classified according to its particle, disintegration and radiation. Α particle, are streams of positively charged particles composed of two neutrons and two protons. They are deflected by electric and magnetic fields. They are not very penetrating, although very ionizing; decay β-; by excess d neutrons, a neutron is transformed into a proton by emitting an electro e-, β + in which a proton of the nucleus disintegrates and gives rise to a neutron. Gamma disintegration: The nucleus of the radioactive element emits a photon of high energy, the mass and the atomic number do not change, only a readjustment of the energy levels occupied by the nucleons occurs. The decay time is governed by the law of kinetics of radioactive decay, depends on the half-life time, for which, the number of initial nuclei is reduced by half.

Nuclear reactions differ from the chemical reactions one is accustomed to studying in chemical engineering, where the electrons of the compounds interact, and generates little energy compared to nuclear reactions. The known nuclear reactions are fission, which is the division of an atomic nucleus and fusion, is the union of two nuclei to form a heavier one. All this is carried out in nuclear reactors, specialized to control these chain reactions, among its fundamental parts: fissionable material, modulators (graphite or heavy water), control rods, thermal transition agent, security system. There is also a variety of nuclear reactors: light water, heavy water, fast feed, refrigerator, Bolshoy Moshchnosty Kanalny reactor, assisted by ADS accelerator, breeding or reproduction. This technology is used for industrial purposes and regrettably for war purposes.

At an industrial level, it is used mainly for the generation of mechanical and electrical energy, and in 2013 there were 439 active nuclear reactors, representing 14% of the world's energy, with 62 in operation and 484 under construction. The country with the highest nuclear technology is currently Russia, former USSR. The levels of safety in the nuclear industries are high, however there are no exceptions of accidents, as is the case of Chernobyl, Ukraine, also former USSR: "The explosion originated from a series of tests that had to be carried out that day inside of the nuclear plant. One of them was to simulate a power cut to check if the turbines of the reactors had enough energy in case of any failure. During this experiment, one of the reactors suddenly increased its power, causing an overheating of its nucleus and the subsequent explosion of the hydrogen that was inside it "(History, 2016). A long time later another nuclear accident occurred, but in this case due to a natural disaster, Fukushima.

These and other accidents have immediate consequences, in the medium and long term, among the most notable are: abandoned cities, death of thousands of people, congenital anomalies. (BBC, 2016). These are consequences for time and dose of exposure to radioactivity. The nuclear industry, in its normal operation, its main problem is the generation of radioactive waste and its final disposal. For the disposal, special containers should be used, minimize the space of the waste, if it is solid, crush it and compact it, if it is liquid, take it to a solid state. After storage in the containers are moved to its final place of disposal, which can be a nuclear pool, nuclear graveyard, deep geological deposit or an isolation in concrete block. Nuclear reactors are currently being designed that can take advantage of the waste from other reactors and thus reduce the volume of unusable material.

Nuclear energy is a "clean" energy, which in the long term leaves its wastes unusable due to the high generation of energy, although work is being done to take advantage of them, there are thousands of radioactive waste deposits that can not be reused and will take a long time in decomposition, being subject to any unfortunate event that may occur, this without counting industrial accidents for human cause or natural cause. There are some countries such as Germany, which is changing nuclear energy by solar and wind energy (ENERGIA LIMPIA XXI, 2016). This makes us think:

How much is nuclear energy really worth?

BBC. (2016). Recuperado el 26 de abril de 2016, de http://www.bbc.com/mundo/video_fotos/2014/03/140326_galeria_chernobil_gerd_ludwig_jg?ocid=socialflow_facebook

ENERGIA LIMPIA XXI. (2016). Recuperado el 2016 de abril de 15, de https://energialimpiaparatodos.com/2016/03/11/149298792/

History. (2016). Recuperado el 26 de abril de 2016, de http://ve.tuhistory.com/hoy-en-la-historia/explosion-en-la-central-nuclear-de-chernobil