Sendai Nuclear Reactor Restart

Both Sendai reactors (unit 1 and unit 2) have now been restarted. Sendai unit 1 has just started providing electricity to the grid. (August 14th)

So how will this affect Japans Carbon Dioxide emissions? And how would renewables (say wind) compare?

When nuclear was shut down in Japan it was replaced with an unholy mix of coal and gas (with about 7% oil) A rough estimate of the amount of Carbon Dioxide from the generation that replaced nuclear would be around 750Kg of Carbon Dioxide for every MegaWatt Hour of energy generated (750KG/MWh)

Sendai, during its last year of full operation generated just short of 13TWh of electricity (13000 GigaWatt Hours) So today, the first day of generation, Sendai unit one (half of the power plant) will have generated around 18GWh of energy. This will displace energy that would have otherwise been generated from the coal/gas/oil mix

So a rough estimate of the amount of Carbon Dioxide prevented from being dumped into the atmosphere by this single day of generation from half a nuclear power plant amounts to 18000 x 750 = 13.5 million Kg of Carbon Dioxide or 13500 Tonnes.

A single day of operation from half a nuclear power plant prevents the emission of 13500 Tonnes of carbon Dioxide.

Amazing isn't it?

How would a renewables option compare?

An 150m high 2MW wind turbine with a typical 25% capacity factor would intermittently produce 12MWh in a day. Or using same units as Sendai - 0.012GWh

So to match the single day output from half of Sendai nuclear power plant (and ignoring the problems of intermittency) would would need 1500 turbines.

Or to put it another way, for a single turbine to match a single days energy generation from half of Sendai nuclear power plant would take that turbine four years, one month and nine days.

Don't figures like that just knock you out?

Sendai Restart and an Early Christmas Gift

The anti-nuclear lobby is getting all bent out of shape by the restart of one of the two reactors in Sendai in Japan. The restart of one of the worlds most effective anti-greenhouse-gas and anti-pollution power generation methods really rubs their medieval superstitions right up the wrong way.

Not to be outdone by the Sendai reactor, I thought I would indulge in a bit of Luddite antagonism as well.

Of course the best way to antagonize a superstitious hysterical self feeding fear monger is by referencing some impeccably researched and peer reviewed science and then to couple that to a small amount of simple mathematics to show that nuclear actually saves lives.

So here goes....( all figures rounded to one decimal place)

Take one Pressurised Water Reactor. As it has just restarted, we'll use the Sendai Reactor - See Wikipedia Here

The Sendai reactor produces just short of 13TWh of electricity per year. As they have only started one of the two reactors on the site then that will be around 6.5 TWh.

Or to look forward to the festive season: 2.2TWh by Christmas.

Now as for out impeccably researched and peer reviewed let us take this table from a paper by Markyanda & Wilson (published in the Lancet, referenced by Jim Hansen among others) (Full Paper Here)

I suppose we should figure out what fossil fuel the Sendai nuclear reactor displaces .... From an earlier post here we have the break down of what has replaced nuclear during the shutdown in Japan. (Post is Here)

Basically it breaks down as follows. Nuclear in Japan during the shutdown was replaced by:

46% Coal
47% Gas
7%   Oil

So the single restarted Sendai reactor (6.5 TWh/yr) will displace approximately 3 TWh coal, 3 TWh gas and 0.5TWh oil in a year.

Or if we want to get into the festive spirit, the Sendai restart will displace approximately 1 TWh coal, 1 TWh gas and 0.2TWh from oil by Christmas.

Lets rephrase these figures into death and illness using the table above.

The deaths, disease and illness prevented in a year from the single unit restarted at Sendai ( i.e. half of a solitary nuclear power plant) will cut pollution by such an extent that it will:

Prevent the deaths of 90 people
Prevent serious illness (hospitalization) of 840 people
Prevent minor (time of work) illness of 45000 people (yes you read it right - 45 thousand)

Or to simply look to Christmas 2015. This single restart late in the year (August) will.

Prevent the death of 10 people
Prevent serious illness in 91 more
and prevent minor illness in no less than 15000 people

Now whether you are a Luddite or not, that is a hell of a Christmas present for 15100 folk in Japan this year.