An estimate on the economic impact of long-term suspension of nuclear power plants

At the start of the Nuclear Regulation Authority in 2012 and the following revision of nuclear regulatory standards, the Nuclear Regulation Authority showed the following policy; 'Business entity must undergo a new regulatory conformity assessment, and the plant that has passed it can be restarted.'As a result, in fact, all nuclear power plants became able to restart only after applying for the new regulatory conformity assessment and receiving the approval about compliance, resulting in the situation of long-term suspension. As of June 2018, only nine plants have been restarted with approval under the new regulatory standards. Until FY2017 after the Fukushima accident, an increase in power generation costs due to additional fossil fuel procurement costs caused by the suspension of nuclear power plants amounted to 9.8 trillion yen.This paper estimated the economic impact of this long-term suspension (hereinafter 'moratorium') based on the concept of opportunity cost. The moratorium period was assumed to be 10 years at the maximum including the future suspension period, and the fossil fuel acquisition cost for the period corresponding to the moratorium for existing 35 reactors under suspension was estimated. When calculating the power cost reduction when operating nuclear plants, which is the difference between the above fossil fuel cost and the nuclear power generation cost, fuel cost alone will be 4.7 trillion yen (2.9 to 6.2 trillion yen in consideration of the uncertainty of fossil fuel price), and if carbon emission price is added to this, it will reach 11.0 trillion yen (9.3 to 12.6 trillion yen).When turning the eyes to the world, the moves that aim to extend the operation until 80 years like in the U.S. are by no means exceptional. If allowing operation until 80 years, its economic effect exceeds the above simple total value of 20 trillion yen, which suggests the magnitude of the impact of nuclear power plant operation. (A.O.)