The Energy of the Stars

Nuclear energy is an alternative to fossil-based electricity generation. It does not consume fossil fuels but uranium, and does not generate any CO2 emissions. Nuclear energy is deployed today in most OECD countries and expanding in other regions of the world, notably those with considerable needs in term of power, such as China or India. Consequently, the market growth is expected to range between 1.3 and 3.8%. It would be one of the highest growth rates among all energy sources.

Nuclear technology continues to evolve. Current nuclear power plants are of the third generation. The design has evolved but the main architecture remains the same; new innovations are being worked on. Fourth-generation reactors should come up around 2030. They will change drastically the energy equation. The current vast majority of reactors use Uranium 235 and Plutonium 239. The use of “slow neutrons” drives the fission reaction. Present-day nuclear fission produces “fast neutrons”, which travel at around 20,000 km/s. A moderator is used to slow them down (Furfari 2007; Vendryes 2001). Research engineers have put together a new technology called “fast neutron” technology which slows down the neutrons to only 500 km/s. There are today three of such plants in the world. Two of them are in Russia and the third one is in Japan (Durand 2007). These reactors can be configured to produce more plutonium than what they consume, and are called nuclear breeders. With these reactors, Uranium 238, an isotope of uranium 140 times more abundant than Uranium 235, can be used for the fission reaction

(Durand 2007). As well, this technology helps produce 60 times more energy than a conventional third-generation plant with the same quantity of uranium. Uranium 233 can be used as well for the reaction. This isotope does not exist naturally but can be manufactured from thorium, which is four times more abundant than Uranium 238. Eventually, nuclear breeder technology could lead to around 300 times more electricity production capacity than current technologies, with the level of waste considerably reduced.

Going further, a new step in nuclear energy could also be reached. Nuclear fusion is a reaction where two atomic nucleuses assemble to form a heavier nucleus. A considerable amount of energy is generated from this reaction. This fusion is naturally at work in most of the universe’s stars, particularly our sun. The hydrogen bomb was designed on this principle. The main issue in nuclear fusion is to control (and tame) the reaction in order to be able to produce energy continuously. The process uses deuterium and tritium, both hydrogen isotopes. Large quantities of deuterium can be found in seawater and tritium can be manufactured, so nuclear fusion fuel is potentially unlimited.

The nuclear fusion process requires bringing the reactor temperature to several million degrees. This technology exists today in Tokamak reactors (CEA 2014), but the reaction still cannot be controlled long enough for this type of reactor to be viable. Nuclear fusion could thus offer, provided it can be controlled, unlimited energy with very little waste. Of course the deployment of this technology would require considerable investment to build the corresponding power plants but it would solve definitely the electricity supply issue.

Like nuclear fission, nuclear fusion presents the advantage of offering considerable amounts of power, something renewable energy cannot do. However, it has the same limitation as nuclear fission. Considerable investments are required to build and operate the plants.

Other than nuclear energy, renewable energies are probably the most promising prospect of the electricity industry in the years to come.

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