Is Japan’s nuclear-free pathway an environmentally friendly choice?

The Fukushima crisis sparked protests and prompted a move away from nuclear energy for Japan

Below is an essay I co-wrote with one of my current Ph.D. students, Sanghuyn Hong. In it, we take a critical look at the current national energy policy of Japan, and highlight the unfortunate implications of a strategy that preferences fossil fuels over nuclear energy.

San, in the first year of his studies, is from South Korea, and is researching current and future energy policies in South Korea, Japan, Australia and New Zealand.

Read or leave your comment the original article here.


On 14 September 2012, the Japanese Government considered a new policy that excited many self-proclaimed environmentalists and anti-nuclear power protesters. Following intense political wrangling, they proposed phasing out the use of nuclear power in Japan by 2040, replacing it with renewable energy (and fossil fuels). This decision, if carried through, has important environmental and financial implications that may come as a surprise to many.

The Fukushima Daiichi nuclear accident on 11 Mar 2011, caused by an earthquake-triggered tsunami, consigned the established Japanese electricity-generation plan to the dustbin. Along with it went Japan’s Kyoto-protocol commitments for greenhouse-gas mitigation.

Originally, the Japanese government had planned to increase nuclear power to 45% and renewables (including hydro) to 20% by the year 2030, up from 26% and 10% respectively in 2010. After the accident, the National Policy Unit in Japan hinted that the original plan was likely to be scrapped in favour of a new scenario, whereby the nuclear target was to be reduced to somewhere between 0–35% and the renewables target increased to 20–30%. Even with an increased share of renewables, the shift away from nuclear under any of the proposed scenarios will lead to greater use of fossil fuels.

To compare the proposed options fairly, we argue that it makes sense take a holistic view of their relative sustainability. To do this, we need to account for a range of environmental and socio-economic factors, including greenhouse-gas emissions, water consumption, land transformation, health and safety issues, and cost of electricity. One should use an evidence-based auditing method like multi-criteria decision-making analysis (MCDMA), which is transparent and relatively objective.

Our recent research (currently submitted to the journal Energy) uses MCDMA to show that even when the negative consequences of using nuclear power are properly factored in (and costs assigned to waste management, accident consequences, and so on), those scenarios with reduced nuclear power result in a less sustainable future in Japan.

In particular, the greenhouse-gas emissions of the nuclear-free scenario can reach up to about 430 kg per megawatt hour. By comparison, in the 35% nuclear-power scenario, it is only 267 kg per megawatt hour, in spite of the higher renewable energy share of the former. Except for the differing nuclear capacity, in all scenarios the ratio of coal to gas power had the largest influence on greenhouse-gas emissions.

Unfortunately, a high dependency on renewables without ongoing support for nuclear in Japan cannot cut the electricity generation sector’s greenhouse gas emissions unless some currently undeveloped alternative forms of cheap, large-scale energy storage are deployed in the future.

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