Implementation strategy of thorium fuel cycle - 005

Nuclear power is called again as a countermeasure of climate change recently. Nuclear power does not emit carbon dioxide (CO2) when it generates electricity. However there are still existing concerns such as the nuclear proliferation, long-term radioactive waste. Nuclear power was not included as a technical method of CDM (clean development mechanism) of Kyoto protocol. The use of the thorium is expected to overcome these concerns. Even though thorium utilization was known in the very early stage of nuclear application in 1940's, thorium was not used as primary source due to its lack of fissile material. Plenty amount of plutonium stock in the spent nuclear fuel from more than 50 years operation of the uranium fuel cycle can be used as starter of thorium fuel cycle. Declaration of the 'world without nuclear weapon' by the president Obama will also help to use weapon grade plutonium for starting thorium fuel cycle. In this paper, I will discuss how much amount of thorium cycle can be implemented triggered by the plutonium stock in spent nuclear fuel and by the weapon grade plutonium. Several implementation scenarios of thorium fuel cycle will be considered. Several types of molten-salt reactor were candidates of thorium nuclear power plant. The capacity of the thorium fuel cycle is estimated to be 450 GWe around at 2050. Some additional discussions on reducing carbon dioxide emission will be carried on rare-earth mining and electric vehicle in view of thorium utilization. (author)