An analysis on the role of nuclear energy system for meeting the future global environmental constraint of $CO_2$ emission regulation was made using an energy-economy interaction model - EFOM-MACRO-KOREA. In case of carbon taxation which is likely to be adopted as policy measure for $CO_2$ abatement, the role of nuclear energy for sustainable energy system as well as the economic impacts has been assessed.
For the analysis, the energy system optimizations under the various scenarios of tax rate and nuclear installation expansion have been achieved using non-linear programing whose objective function is the summation of discounted utilities of whole periods.
As a result, the role of nuclear energy system up to the year 2040 is forecasted. In order to stabilize the carbon emission during the whole period to the emission level of 2005 at business-as-usual scenario, the carbon tax of 400 US dollars per ton of carbon is required. For two scenarios with the same tax scheme and different nuclear installation growth, the smaller the nuclear growth, the more GDP loss and $CO_2$ emission. Required nuclear energy capacity for stabilization would be over 80 additional nuclear power units. However, the maximum proposed sites in Korea is about 40 units. The realistic limitation to nuclear power expansion would be siting due to the public acceptance.
The results shows that the adopted modeling approach is suitable for the impacts analysis of the environmental policy such as carbon tax imposition which affects economy as well as the energy sector.