Evaluation of CO2 emissions in the life cycle of tokamak fusion power reactors

Global warming is one of the most serious problems which human beings are currently facing. Carbon dioxide (CO2) from power plants is considered one of the major causes of global warming. In the present study, CO2 emissions from tokamak fusion power plants are compared with those from present power generating technologies. Plasma parameters are calculated by a systems code that couples the ITER physics, toroidal field coil shape and cost calculation. CO2 emissions from construction and operation are evaluated by multiplying component volume by the CO2 emission intensities of the component materials. The reactor building, balance of plant, etc., are scaled from the ITER reference power reactor ('ITER-like') by use of the Generomak model. The most important finding is that CO2 emissions from fusion reactors are less than those from photovoltaic systems and less than double those from fission reactors. The other findings are that: (i) Most CO2 emissions from fusion reactors are from materials. (ii) CO2 emissions from reactor construction account for almost 60-70% of the total, with the rest coming from reactor operation. (iii) The reversed shear reactor can reduce CO2 emissions by half compared with the ITER-like reactor. It is concluded that tokamak fusion reactors are excellent for their low CO2 emission intensity, and that they can be one of the effective energy supply technologies to solve global warming. (author)