Opinion of the French Academy of Sciences (8 May 2021): The contribution of nuclear energy in the energy transition, today and tomorrow

 French Academy of Science is the leading scientific authority in France

Texte intégral : https://www.academie-sciences.fr/pdf/rapport/20210614_avis_nucleaire.pdf

Extraits

1) The energy transition: "The energy transition, to be implemented to limit our greenhouse gas emissions and the global warming that results from it, must result in:

- a reduction in our energy consumption per person; - a reduction in our dependence on fossil fuels, primarily coal and oil, and secondly gas;

 - an increase in the share of low-carbon energy sources (renewable energies and nuclear energy); These developments will inevitably lead to a significant increase in the share of electricity in energy production and consumption, reaching a level of around 700 to 900 TWh (terawatts-hour) in 2050, almost double our current electricity production. This electricity must be as decarbonised as possible.

Comment: As the Academy of Technologies had already noticed, this level of 700 to 900 TW.h confirms that the Multiannual Energy Programmation Law  (PPE) must be seriously reviewed. (650 TW.h). As well as all the scenarios, eg @RTE that rely on it.

2) Renewable energies: "Intermittent and variable renewable energies, such as wind and solar photovoltaics, cannot, on their own, supply an electricity grid with power in a stable and controllable way if their random nature is not compensated. This requires massive energy storage capacities and/or controllable backup power generation units. The massive storage of energy, other than that already carried out by means of pumped-storage hydroelectric power stations, would require capacities that are not seen to exist in the coming decades. Pilotability, in the absence of the latter, can only be ensured by nuclear power stations, if we exclude thermal power stations using fossil fuels..

3) Nuclear and CO2  : "A conventional RNT (Thermal Neutron Reactor) massively injects, 24 hours a day, at least for some 300 days a year, decarbonized electricity into the grid. Nuclear power generation is, in fact, of all sources of electrical energy, the least emitter of greenhouse gases (about 6 grams of CO2 equivalent per kWh produced). »

4) Nuclear and environmental impacts :  "A comprehensive life cycle analysis of electrical systems shows that the non-radioactive environmental impacts of nuclear power are most often much lower than those of other systems. As far as radiological impacts are concerned, they remain, in normal working conditions, much lower than those associated with natural radioactivity. On the other hand, those linked to major nuclear accidents have necessitated the evacuation of large areas in order to avoid extraordinary radiological exposures and have had serious social and environmental consequences. Feedback from these accidents has led to successive improvements in reactor safety. Since 2011, EPR-type reactors, third generation pressurized water reactors (EPRs), have been designed to minimize the accidental release of radioactivity into the environment, thanks to technological provisions and more stringent safety regulations

5) Nuclear Waste: "Medium- and high-level waste with a long life, which is the most delicate to manage, has a volume of the order of 1.4 m3/TWh electric for the French fleet (the total volumes of this waste since the beginning of the nuclear era are respectively 42,700 m3 and 4,090 m3). The inventory of all the waste from the French nuclear fleet is regularly updated by the National Agency for the Management of Radioactive Waste (Andra)...

Deep geological storage, under conditions of safety and reversible management, controlled by the Nuclear Safety Authority (ASN), is well suited to long-lived waste. In this context, the application for the creation of Cigéo (Industrial Center for Geological Storage), after twenty years of research by the national scientific community, is ready to be filed with the Ministry of Ecological Transition to be examined by the ASN "

6) RNRs (breeder reactors): From the beginning of the program, the nuclear power policy aimed at the possibility of installing a fleet of fast neutron reactors (RNR) in order to make better use of uranium resources and thus extend the production of nuclear power... The most mature RNR model is a reactor using liquid sodium as the heat transfer fluid for energy: RNR-Na. The feedback from these reactors is important, especially in France, which operated Phoenix, Superphénix and led for 10 years the Astrid project foreshadowing the fourth generation RNR (RNR GenIV).

The Multiannual Energy Programming (PPE) has recently postponed to the next century a deployment of the RNR, leading to the abandonment of the ASTRID project of the CEA. As a standby strategy, it decided to move towards the multirecycling of plutonium from spent fuel in NTRs, particularly EPR reactors. This strategy is intended to maintain France's R&D expertise to move towards the RNRs. It can stabilize the quantities of spent fuel but does not lead to the energy autonomy as sought with the RNR. 

7) Recommendations:

- to maintain the nuclear power capacity of France's energy mix by extending the reactors in operation, when their operation is ensured under conditions of optimum safety, and by building third-generation reactors, the EPRs, in the immediate future. The latter are based on the best technology currently available and offer the best guarantees of safety;

- initiate and support an ambitious R&D program on the nuclear of the future in order to prepare for the emergence in France of innovative fourth generation fast neutron reactors (RNR), which constitute a solution for the future and whose study is actively continuing abroad;

- to take into account in this programme all the scientific aspects of fuel recycling associated with reactors, including the management of radioactive waste;

- maintain training courses to attract the best young talents in all fields of physics, chemistry, engineering and nuclear technologies to develop national skills at the highest level;

- inform the public in full transparency about the constraints of the various energy sources, the complete analysis of their life cycle and the contribution of nuclear power in the current energy transition.