Expert Profile
Mr. Sébastien Candel
2019/3/13 13:24:23
Abstract:The report underlying this presentation is jointly released by the Chinese Academy of Engineering, the National Academy of Technologies of France and the French Academy of sciences. Responding to societal concerns about the environmental consequences of human and industrial activities, it focuses primarily on the environmental impacts of nuclear energy in normal and accidental situations, including waste management and aims at providing a comprehensive analysis of these issues. Two major questions are considered in this presentation: (1) Evaluation and control of the radioactivity released by nuclear installations under normal operation, (2) Management of long-term radioactive spent fuel and radioactive waste, notably those that will be disposed of in geological repositories. The report emphasizes that in the context of climate change, nuclear energy, with its very low emission of GHG, has a unique capacity to generate massive and on-demand dispatchable amounts of electricity. In contrast to fossil fuel fired plants that emit, important quantities of air pollutants such as particles, NOx, SOx, and heavy metals, nuclear power plants do not. This is an essential asset at a point in time where air quality has become a major problem in many countries and where nuclear energy could replace fossil fuel powerplants and contribute to improve the situation. Furthermore, it is indicated that under normal operation, radioactive releases by NPPs are of the order of a few per cent of the authorized levels, which are well below the levels of natural radiation. This is why the report concludes that the impact of nuclear power plants under normal operation is negligible or quite limited in terms of radioactivity. Under normal operation, the major environmental impact from nuclear energy is due to the front-end activities, related to uranium mining. This might be reduced in the future with a more efficient burn-up of uranium fuel in GEN-III and GEN-III+ installations and more substantially diminished with GEN-IV reactors. Another matter of concern is that of water withdrawal and consumption. This needs to be considered when siting inland nuclear plants in view of water availability. Turning to the issue of nuclear waste management, it is concluded that present waste management policies are based on the latest technologies for waste confinement, including disposal of high-level long-lived radioactive waste in deep underground repositories. It is noted that considerable effort has been expanded to define sustainable management of high-level radioactive waste with final disposal in geological formations. In this respect, simulations indicate that the potential migration of radionuclides through the confinement barriers and hundreds of meters of overlying bedrock over geological times (hundreds of thousands of years) is limited to the extent that the additional radioactivity from this phenomenon will be less than a percent of natural background radiation.
