Energy from these sources may be classified non-conventional, as both the methods are not commercially available and not extensively used. Research is going on to make commercial power generation feasible from these sources.
French physicist Henri Becquerelin discovered nuclear energy accidentally in 1896. Becquerelin found that photographic plates stored near uranium compounds reacted as though they had been exposed to light in a way similar to x-rays, which had also just been discovered.
Nuclear Fusion Breeder Reactors
In a fast breeder reactor, no moderator is used to slow down the neutrons produced by fission. In fact, it relies on unimpeded fast moving neutrons to keep the reaction going. Most neutrons miss their target. But when they hit, each spawns several new neutrons.
A nucleus of Plutionium-239 (239Pu) bombarded with a best neutron will release on the average three neutrons, which go on to split more Pu. With proper design, it is possible to use these neutrons to convert nuclei in a surrounding blanket of Uranium-238 (23SU) into 239Pu. With proper design, it is possible to use these neutrons to convert nuclei in a surrounding blanket of Uranium-238 (238U) into 239Pu. These reactors breed more Pu than that actually went into it.
A reprocessing plant can extract this Pu. Mix it with more depleted U and so get an almost endless source of energy. In a conventional nuclear reactor, only about one per cent of the energy content of the fuel is released. But in a fast breeder reactor, release is about 80 per cent.
Nuclear fusion can be a new potential source of energy. When two hydrogen nuclei are fused together to make a helium nucleus, plenty of energy is released. This is the energy source of sun “and other stars.
This fusion takes place at such a high temperature that matter exists as plasma. Fusion releases more energy than fission. Also, power generation from nuclear fusion is relatively less polluting.
Controlled fusion, as a source of energy was one of the greatest scientific dreams of the post-1945 world. Now technology has advanced to such a level that it is possible to go for the commercial plant in future.
Deuterium is the fuel for fusion reaction and ocean is its main source. For every 6,500 hydrogen atoms, there is one deuterium atom. It has been estimated that one tone seawater can contribute 34 gm of deuterium.
It is equivalent to about 300 tonnes of coal. So, considering the whole of ocean water (about 1.5 x 108 tonnes), even if we harness just one per cent of the deuterium available, it will be equivalent to about 5 lakhs times the present known coal reserves put together. So vast is the potential of the technology.
Nuclear reactors produce energy from uranium through an atomic fission reaction – that is, radioactive atoms are split apart and the energy that is released in that fission is harnessed to produce heat and electricity.
A total of 438 nuclear power plants were operating around the world at the end of 2000, according to data reported to the Power Reactor Information System at the International Atomic Energy Agency (IAEA).
The plants had a total net installed capacity of 351 GW (e). Also during the year 2000, six nuclear power plants representing 3056 MW (e) net electric capacity were connected to the grid: one in Brazil, one in Czech Republic, three in India and one in Pakistan.
The six nuclear plants located at Tarapur, Kota, Kalpakkam, Kokrapara Rowathbatta and Narora accounted for 2.51 per cent of the total energy generated in India from various sources.
Thus, the share of nuclear energy during 2002-03 was insignificant, though the proved reserves of uranium, monazite and limenite amount to 30,000, 50,000 and 80,000 tonnes respectively. The nuclear energy supplements the energy being generated by conventional sources.
While nuclear power accidents are rare, they can have devastating effects on public health and the environment. Radiation emitted can damage an environment making it unlivable, as was the case with Chernobyl. High levels of radiation, along with sustained exposure, can also alter living cells to the point it becomes impossible to repair, resulting in death due to radiation poisoning.
People are exposed to radiation everyday from the sun, cell phones, TVs, and even foods like bananas and Brazil nuts. Radiation is also used in hospitals to help patients fight illnesses, such as cancer. Under normal conditions, nuclear power facilities do not emit dangerous levels of radiation. Despite this, there continues to be fear due to the possibility of an accident that would expose people to potentially fatal levels of radiation.