The history of France's civil nuclear program traces the evolution that led France to become the world's second largest producer of nuclear-generated electricity by the end of the 20th century, based on units deployed, installed capacity, and total production. Since the 1990s, nuclear energy has furnished three-fourths of France's electricity; by 2018, this portion had reached 71.7%.
At the start of the 20th century, France made significant contributions to the discovery of radioactivity and its initial uses. In the 1930s, French scientists uncovered artificial radioactivity and the mechanisms behind nuclear fission, placing the nation in a leading position within the field. However, World War II halted France's ambitions. When Germany occupied France, research relocated to the UK and subsequently to the US, where the first nuclear reactors and weapons were developed.
After World War II, France initiated an extensive nuclear program with the establishment of the Commissariat à l'Energie Atomique (CEA), but due to resource constraints, it took a considerable amount of time to achieve substantial progress. In the 1950s, the pace accelerated as France initiated a military nuclear program, which led to the creation of a deterrent force in the subsequent decade. Simultaneously, France commenced the construction of its first nuclear power plants, which were intended to produce plutonium and electricity.
In the 1970s, fueled by the oil shocks, the Pierre Messmer government decided to utilize "all-nuclear" power generation in France. This decision led to the construction of 58 standardized nuclear power reactors throughout the country for the next 25 years. Even though domestic technology was abandoned, French industrialists quickly incorporated the American technology they had chosen and exported it to South Africa, South Korea, and China. At the same time, France was developing expertise in managing the nuclear fuel cycle by constructing the largest civil reprocessing plant in the world at La Hague, as well as experimental fast-breeder reactors.
Although the anti-nuclear movement had less of an impact in France than in other European countries from the 1980s onward, radioactive waste management emerged as a crucial issue in public discourse in France.
In addition, the conclusion of the equipment phase, along with the liberalization of the electricity market, and the growing anti-nuclear movement bolstered by nuclear disasters such as Chernobyl and Fukushima, are causing changes in the French nuclear industry. Consequently, since 2015, initiatives have been made to decrease the proportion of electricity created by civil nuclear power in France, in order to accommodate renewable energy sources. Nevertheless, construction of new-generation French reactors, including the European Pressurized Reactor (EPR), persists domestically and internationally.
Research for future solutions is concentrated on Generation IV reactors and nuclear fusion. Meanwhile, shutting down reactors presents new challenges.
President Macron announced in February 2022 his plan to restart the civil nuclear program to construct six to fourteen new reactors while also expanding the lifespan of current nuclear reactors "as much as possible."
The scientific adventure of the atom (1895-1945) In just fifty years, from the initial detection of X-rays to the development of nuclear reactors and weapons, the scientific pursuit of the atom completely changed the world. France was a prominent player in the field, courtesy of the Curie family's contributions, until World War II caused a severe setback to national efforts.
The origins (1895-1932)
By the end of 1895, German physicist Wilhelm Röntgen demonstrated that a cathode-ray tube produced invisible radiation capable of penetrating matter.(fr) Mallevre, 2006 , p. 10. This discovery, named "X-rays," earned him the first Nobel Prize in Physics and piqued the scientific community's interest. The next year, French physicist Henri Becquerel searched for a connection between phosphorescence and X-rays. He subsequently observed that uranium salts, also known as phosphorescent rocks, emitted radiation even if they weren't exposed to light. These emissions came to be known as Becquerel rays or uranic rays because they were believed to be unique to the element.(fr) Mallevre 2006 , p. 11.
Pierre and Marie Curie discovered that uranic rays vary in intensity depending on the uranium ore. Starting in 1898, they aimed to isolate the element responsible for this phenomenon. By manually refining hundreds of kilograms of uraninite, they discovered the first element in July, which they named polonium in honor of Marie's homeland. In December, they found a second, even more reactive element: radium. Additionally, they co-discovered the activity of thorium. The Curies were awarded the Nobel Prize in Physics in 1903, jointly with Henri Becquerel, for their discovery of natural radioactivity. In 1911, Marie Curie was presented with the Nobel Prize in Chemistry for her isolation of radium and polonium. In 1899, New Zealand-born physicist Ernest Rutherford discovered two types of radiation, alpha and beta rays, which were less penetrating than X-rays. In 1903, he linked these rays to the Curies' discoveries and proposed a hypothesis that the radioactive elements in uranium and thorium were linked together, with the heavier element spontaneously losing its substance through decay to give rise to a lighter element and so forth. In 1911, Rutherford suggested a novel depiction of the atom's structure subsequent to a well-known experiment: a nucleus that bears positively-charged particles attracting negative charges, namely electrons. Niels Bohr, a Danish physicist, modified Rutherford's model using Max Planck's initiated quantum theory and showed that electrons do not collapse towards the nucleus due to attraction, and rather remain at a specific level, which is also known as Bohr's model.(fr) Mallevre 2006 , p. 12. Finally, in 1919, Rutherford demonstrated that the hydrogen atom's nucleus was present in all other nuclei and labeled it the proton. He also hypothesized the presence of neutral, uncharged particles in the nucleus, alongside protons.
In 1930, the Germans Walther Bothe and Herbert Becker noticed that when alpha rays bombarded lithium, beryllium, and boron, these elements emitted "ultra-penetrating" rays. Intrigued by these findings, Irène Curie, the daughter of Pierre and Marie Curie, and her husband Frédéric Joliot, embarked on a mission to comprehend the radiation's nature. They found that it could set protons in motion in January 1932. Following this discovery, James Chadwick, an Englishman and a former disciple of Rutherford, uncovered the last piece of the atomic puzzle: neutrons, the following month.(fr) Mallevre 2006 , p. 13.
Discovery of nuclear energy (1933-1939)
Nuclear physics was born from the work of Frédéric Joliot and Irène Curie. In late 1933, they used alpha radiation to bombard aluminum foil and demonstrated the production of radioactive phosphorus-30, a phosphorus isotope. They concluded that irradiation could produce new radioactive elements. From the outset, they anticipated numerous applications in medicine, particularly with radioactive tracers. For their groundbreaking discovery, they were honored with the 1935 Nobel Prize in Chemistry.
In 1934, Enrico Fermi of Italy found that slowed-down neutrons (such as those that have passed through kerosene) were more efficient than regular ones, leading to the necessity for the use of "moderating" materials like heavy water in future facilities.(fr) Mallevre 2006 , p. 14. Numerous European research laboratories were subjecting nuclei to bombardment for analysis of their effects. In December 1938, two German exiles residing in Sweden, Lise Meitner and Otto Frisch, discovered a crucial explanation for nuclear energy: the phenomenon of fission. In February 1939, Niels Bohr confirmed that inside natural uranium, there exist two isotopes; 238U and 235U. However, only uranium 235 is "fissile". Although it is the rarer of the two, accounting for only 0.72% of uranium, enriching uranium ore is necessary to increase the proportion of fissile material and obtain a more reactive fuel. Finally, in April 1939, French physicists Frédéric Joliot-Curie, Hans von Halban, Lew Kowarski, and Francis Perrin published an article in the journal Nature. The article demonstrated that uranium nucleus fission accompanies the emission of 3.5 neutrons (later corrected to 2.4), which can subsequently fragment other nuclei resulting in a "chain reaction" phenomenon. This fundamental finding in nuclear physics was published shortly before their American competitors.
In May 1939, four French individuals filed three patents. The initial two patents concerned uranium energy production, and the third one, a confidential patent, was for improving explosive charges.(fr) Reuss 2007, p. 17.(fr) Mongin Dominique, "Aux origines du programme atomique militaire français", Matériaux pour l'histoire de notre temps, no 31, 1993, pp. 13-21 (, read online archive). Joliot, who strongly believed in the future significance of atomic energy, met Minister of Armament Raoul Dautry in the fall of the same year. Dautry provided full support for the development of explosives and the production of energy.
July 1939 saw the start of experiments at the Collège de France laboratory on the release of energy through chain reactions, which continued at the Atomic Synthesis Laboratory.(fr) "The Atomic Synthesis Laboratory, fundamental research and the scientist's responsibility" archive, on Union rationaliste (accessed March 19, 2017).(fr) Ivana Gambaro, Les laboratoires de F. Joliot entre la physique et la biologie: Atti del XVII Congresso Nazionale di Storia della Fisica, Como, Villa Olmo 24–25 May 1996, Gruppo Nazionale Storia Fisica, CNR, 1996 (read online archive). To safeguard his patents, Joliot established an industrial network around him, primarily via an agreement between CNRS and Union minière du Haut-Katanga, who owned the uranium in Belgian Congo.(fr) Bendjebbar 2000, p. 29.
In the fall of 1939, the Joliot team recognized that France lacked the capability to enrich natural uranium to its fissile isotope (235U). As a result, they opted to employ heavy water to construct an atomic reactor.(fr) Bendjebbar 2000, p. 33. Following the request of the Collège de France in February 1940, Raoul Dautry dispatched Jacques Allier on a clandestine expedition to Norway to reclaim the complete inventory of heavy water held by Norsk Hydro, a partially French-owned corporation, which Germany also coveted.(fr) Mongin 1993, p. 13.
Suspension of research in France (1940-1945)