Air Pollution as a Climate Forcing: A Workshop

Day 3 Presentations

Preliminary Estimation for Contribution of Nuclear Power to Reduce Emission of Air Pollutants from Electricity Sector in Japan

Okabe Yoshinobu
Central Research Institute of Electric Power Industry, Chiyoda-ku, Tokyo, Japan

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Time chart (1970-1997) of electricity source mix in Japan
Time chart (1973-1997) of CO2 emission from Japan electricity sector
Figure 1: The first figure shows the historical trend of electricity mixes in Japan in the last 30 years. The second figure shows the total CO2 emission from the electricity sector in Japan and the hypothetical CO2 emission assuming nuclear energy had not been introduced (the blue region is the actual emission).

Nuclear power plants emit almost no air pollutants such as SOx, NOx, particulates and greenhouse gases (GHG) during plant operation, and their energy balance, i.e. the ratio of energy output versus energy input, is very low compared to fossil fuel energy. These facts imply that the introduction of nuclear power contributes to reducing the emission of these air pollutants. Of course, it is not possible to evaluate exactly what would have happened if nuclear power had not been introduced, because, elimination of nuclear energy from energy options would have changed the entire structure of economic activities relating to energy production and consumption. For the same reasons, evaluation of contributions of nuclear power to mitigating air pollution in the future is also difficult. Nevertheless, it is possible to provide useful estimates of how the introduction of nuclear power mitigated the environmental impact in the past or how it can mitigate the air pollution in the future. This paper first describes the energy mixes of the past in Japan and the history of the improvement of emission factors of air pollutants. This paper also provides preliminary results of calculations of the emission of air pollutants from the electricity sector in Japan in the case nuclear power had not been introduced but instead the electricity had been produced by thermal power. We also provide some consideration of the role of nuclear energy in the future.

Workshop Homepage * Background
Summaries: Overview, Gases, Aerosols, Tech., Health, Agri./Eco.
Abstracts: Day 1, Day 2, Day 3, Day 4, Day 5 * Participants