According to the International Atomic Energy Agency (IAEA), there are currently 443 nuclear power plants in operation worldwide. Fifty more are also under construction in 19 countries.
In France, CEA, EDF, Naval Group and TechnicAtome are working together on the Nuward SMR, a pressurised water reactor technology designed to meet the growing needs of the global carbon-free electricity market.
Originally, SMRs were intended to bring electricity to remote geographical areas - an inevitably limited market. More recently, EDF has put forward the idea of replacing coal-fired power plants with small reactors.
The Nuward consortium is currently working on the design phase of its project. This phase, which will be completed by the end of 2022, includes the development of complete architectural plans for the plant and the making of important choices to define the safety of the reactor.
Several countries are investing in fourth generation nuclear reactors.
Generation IV nuclear power involves a system of fuel fabrication plants and reprocessing facilities that together would overcome some of the shortcomings of current nuclear power plants.
Plutonium is formed when uranium-238 captures neutrons from nuclear fission reactions. Most of these reactors need to be fuelled with uranium-235, but most fourth-generation reactors only need uranium-238 to operate.
The design of Generation IV reactors incorporates a number of technological advances to meet the criteria of sustainability, nuclear safety, economic competitiveness and resistance to nuclear proliferation
Thorium is a metal that could be used in molten salt reactors; one of the next generations of nuclear power in which the reactor coolant and the fuel itself are a mixture of hot molten salts.
Th-232 is of interest for nuclear power generation because it can easily absorb neutrons and transform into Th-233. Th-233 can become protactinium-233, which in turn becomes a fissile and energy-producing isotope: U-233.
Thorium has many qualities but also many disadvantages: difficult to handle, fertile and non-fissile metal, higher risks.
But it produces less waste than plutonium or uranium and remains an attractive option for the future of nuclear energy.
Isabelle Dumé holds a PhD in physics. She collaborates with various scientific magazines and media, public and private institutions, and actors in higher education and research in France and worldwide.