The potential of CO2 emission reduction is analyzed by the MARKAL model for the Japanese energy system in the time horizon 1985-2030, taking into account such reduction measures as energy conservation, fuel switching, and technology substitution. Among them, nuclear energy utilization is found to have a large CO2 reduction potential, i.e. from 10% reduction of the total emission in 1990 to the levels of 16%, 21% and 42% in years 2000, 2010 and 2030, respectively, through electric power generation and process heat application.
