The development of nuclear energy throughout the world depends on total safety and a solution to the problems of waste.
Current research efforts are oriented towards reactors that are even safer and capable of burning their own waste.
But whilst we await these 4 th generation reactors, work proceeds on projects involving the 3 rd generation transitional reactors with their higher safety standards and improved profitability, without fundamental technological breakthroughs.
The EPR reactor is part of this 3 rd generation.
Other models are under study in other countries: in the United States, Russia and Asia.
At the same time, researchers are working on
reactors of the 4 th generation, which are unlikely to be operational on an industrial scale before 2034/2040.
And nuclear fusion?
For many years, scientists have dreamt of using nuclear fusion to produce energy on an industrial scale.
This is the energy that is the basis of radiation from the sun and stars. It involves obtaining the fusion of certain light nuclei that form a heavier nucleus on joining together, and discharge energy.
The principle:
The elements that constitute the nucleus of atoms stay together as a result of an energy called the binding energy. Protons, which are all of the same sign, should mutually repulse each other. In fact, they stay together due to the binding energy. This binding energy, which has replaced a tiny part of the mass of the nucleus, is not the same for all nuclei. It is weak for the lightest elements (hydrogen, helium, lithium). If the light nuclei can be made to fuse together, a heavier nucleus is obtained, but of a total mass inferior to the sum of the masses of the initial nuclei. This fusion reaction releases energy corresponding to the loss of mass. A nucleus of deuterium (1 proton + 1 neutron) is made to collide with a nucleus of tritium (1 proton + 2 neutrons), the two fuse to form a helium nucleus (2 protons + 2 neutrons). One neutron is expelled and the reaction liberates energy.
The difficulty comes from the fact that the nuclei, with positive electrical charges, repel each other. It is necessary therefore to create extreme conditions, a plasma, to overcome this obstacle. Very high temperatures (100 million °C) are necessary.
The advantage: the most feasible fusion reaction to produce is that of 2 hydrogen isotopes, deuterium and tritium. Deuterium is found in water and tritium is obtained by bombarding the nuclei of lithium with neutrons. Deuterium, lithium and helium are not radioactive. Nuclear fusion therefore results in a lot less radioactive waste than fission, for the same quantity of energy produced.
Research into fusion has been undertaken for many years at an international level under the sponsorship of the IAEA (theI International Atomic Energy Agency) within the framework of the ITER project. This project brings together the United States, the European Union, Japan, China and South Korea. The aim is to succeed in maintaining this fusion reaction and to identify the technologies, essential for a future reactor. Two sites were in competition for the project, one in Japan, the other in France at Cadarache. The latter has been chosen by the different partners to house the ITER reactor. It will only be at the end of this project, which could last 20 years or so, that we will perhaps be able to envisage moving to an industrial scale.
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