EDF study confirms very low carbon nature of nuclear

EDF said the study - published on 16 June - was carried out on the nuclear fleet in operation, and according to a standardised methodology. "It is integrated and relates not only to the climate change criterion, but also to nine other environmental impact criteria, in order to assess not only the transfers between stages of the life cycle, but also between criteria," it noted.

"The LCA methodology is standardised, its implementation requires great rigor and the collection of a considerable amount of data for which the professions have been strongly solicited," EDF said. "This study was critically reviewed by a panel of independent experts, whose complementarity met the requirements of ISO 14044 and ISO/TS14071."

These experts consider "that the results provided respond adequately and credibly to the objectives mentioned and that they have been established in compliance with the standards mentioned".

The scope of the study includes data from EDF's nuclear fleet in 2019: 34 900 MW reactors, of which 22 use mixed-oxide (MOX) fuel, 20 1300 MW reactors, and 4 1450 MW reactors. It therefore takes into account the production of the two Fessenheim units, shut down in 2020. The study does not take into account the transmission of electricity.

The analysis found that electricity generated by the fleet emitted a total of 3.7g CO2 equivalent per kWh. The upstream phases of the cycle account for 57% of these emissions, while the 'production' stage represents 28%. Construction represents 16%, with the main contributors being cement (6%), non-alloy steel (3%) and reinforcing steel (2%). Decommissioning represents only a marginal share: 3%, while exploitation represents 9%.

Sensitivity studies show that a 60-year reactor operating life reduces the carbon footprint by 8% (3.4g CO2/kWh) compared with a 40-year operating life. The impact of a 10% change in annual electricity production compared with 2019 is 0.1 g CO2/kWh, EDF said. The company concludes that the overall sensitivity offers a range of 2.9-4.6g CO2 eq/kWh.

EDF said the result of the LCA "confirms the very low carbon nature of this energy. The study also aims to identify the most efficient environmental improvement actions and is part of an environmental management objective. It aims at a better understanding of the contributions of each step."

The company noted the reference figure for nuclear power at the international level is that of the Intergovernmental Panel on Climate Change: 12g CO2 eq/kWh. In France, the Agency for the Environment and Energy Management (Ademe), in its database, estimates the emissions of a nuclear kWh at 6g of CO2. By comparison, the emissions from gas-fired power plants are estimated again by Ademe at 418g CO2 per kWh and those from coal-fired power plants at 1058g CO2 per kWh. As for renewable energies, the kWh in France is around 10g for wind energy and 30g for photovoltaic solar energy.

In early 2018, the EDF group made a commitment to reduce its direct CO2 emissions (excluding the life cycle analysis of generating plant and fuel) by 2030 by 40% compared with 2017, aiming to bring them down from 51 million tonnes to 30 million tonnes by 2030. In February 2020, it made a commitment to achieve carbon neutrality by 2050.

EDF said the electricity it produces in France is more than 97% CO2-free, thanks to nuclear power and renewable energies. It has 56 reactors in operation and one under construction.

The group's nuclear output in France in May 2022 amounted to 20.5 TWh, down 7.0 TWh compared with May 2021. Since the beginning of the year, the cumulative output amounted to 133.9 TWh, down by 20.1 TWh year-on-year due to a lower availability of the nuclear fleet mainly in relation to the impact of the detection of indications of stress corrosion.