Over the next two decades, the cost of replacing nuclear with fossil fuel generation in Japan will be about $1.2 trillion, most of it in the cost of natural gas. This cost does not include financing, insurance or other non-operating or non-construction costs. It will take about ten years to fully implement this new mix.
Over the next two decades, the costs of keeping the nuclear fleet afloat is about $225 billion, much less than the fossil fuel alternative
Materials and fuel are more costly in Japan relative to the U.S., and labor is slightly cheaper. So in $US, replacing Japan’s approximate 300 billion kWhrs/yr of nuclear with a mix of a third coal (twenty-one 750 MW plants with a capcity factor of 71% @ $2.5 billion each) and two-thirds gas (thirty-three 880 MW plants with a capacity factor of 80% @ $820 million each) will cost about $80 billion in construction. But the additional fuel costs for these plants will be about $4 billion/yr @ 4¢/kWhr for coal and $40 billion/yr @ 18¢/kWhr for gas, or about $44 billion/yr. Operating costs for these new plants would total about $15 billion/yr @ 0.5¢/kWhr for each fuel type.
The cost of restarting for the existing nuclear fleet, minus the Fukushima reactors, is $1.8 billion/yr in fuel @ 0.6¢/kWhr, and $3.9 billion/yr in operating costs @ 1.3¢/kWhr, or $5.7 billion/yr total. Upgrading the capacity of the existing fleet to achieve 300 billion kWhrs/yr will cost about $25 billion, extending the life-span of a dozen will cost about $6 billion, and building a dozen new ones to replace older ones will cost about $80 billion.
This cost does not include insurance, financing or other non-operating or non-construction costs. Different assumptions can change the details but the difference will still be about five times. And restarting the nuclear fleet can be done now when the country needs it most.