Posted by & filed under Global Warming/Climate Change, Nuclear, Peak Oil.


Nuclear Fusion in the sun
already powers our lives

If you could compare all the different applications of clean technology (solar, wind, etc.) to horses in a race, I guess you could say that Nuclear Fusion is the ‘long shot’. It’s the old nag that everyone expects to come in last, if it comes in at all. But, as long shots do, if it does come in the pay-off would be huge.

Often slated to be a fifty year project, the time-frame has recently been chiselled down to a ‘modest’ thirty years – maybe.

What’s Nuclear Fusion? Take a look at the sun (actually, don’t do that…). The sun, if I am to believe what my teacher told me as a kid, is a great big ball of burning gas. When I was small I always wondered why it didn’t, as gas does, just explode or rapidly burn itself out. This is Nuclear Fusion. Under intense heat the nuclei of certain elements fuse together, with the new form being more stable than the original elements, and, wait for it, releasing significantly more energy than was originally evident (depending on the elements being fused).

When I say “significantly more energy” I’m speaking in a true British understated kind of way. A BBC report will help amplify:

One of the attractions of fusion is the tiny amount of fuel needed. The release of energy from a fusion reaction is 10 million times greater than from a typical chemical reaction, such as burning a fossil fuel.

A 1GW [gigawatt] fusion power station would burn about 1kg of deuterium and tritium per day, compared with a 1GW coal power station burning 10,000 tonnes per day of coal…

The raw materials to produce this reaction are water and lithium. Lithium is a common metal, in daily use in mobile phones and laptop batteries.

Used to fuel a fusion power station, the lithium in one laptop battery, complemented by deuterium extracted from 45 litres of water, would produce some 200,000 kWh of electricity – the same as 40 tonnes of coal and the equivalent of the UK’s current per capita electricity production for 30 years.

There is enough deuterium for millions of years of energy supply, and easily accessible lithium for several thousands of years. – BBC


EFDA-JET
Torus with superimposed photo of
plasma from an Infra Red camera

What’s the downside you ask? According to the promoters of the technology, there aren’t any. Unlike traditional nuclear power stations (nuclear fission), Nuclear Fusion has no ‘runaway reactions’, and no radioactive waste (the byproduct of the process being helium, a harmless gas). We are also told, emphatically, that Nuclear Fusion will not contribute greenhouse gases to the atmosphere.

What’s the big hold up then? Well, there’s just that little issue of creating a sun-like environment, down here on planet earth:

To initiate the fusion reaction, hydrogen gas must be heated to over 100 million Celsius (10 times hotter than the core of the Sun), for the fuel particles to fuse rather than just bounce off each other’s electrical charge in the resulting plasma. – BBC

Yes, yes, I know. It sounds impossible, and impossibly expensive to boot. Hence the ‘old nag’ analogy above. But it seems necessity can be the parent of creativity. Although not managing to output more energy than input, the JET project in the UK (operating with worldwide cooperation) has made enough experimental headway that, with the additional pressure of recent climate-change activity worldwide, many world leaders are now willing to invest in further development.

With the time frames involved, especially in the context of recent scientific predictions about the state of the world in thirty to fifty years from now, I hope they won’t put all their money on the one horse – indeed, with world economies likely to tumble in the short term, there’s a good chance they’ll spend billions of dollars now, but never complete the task before funding vanishes….

The ETA for pulling this off is around thirty years or so, so, um… watch this space.

Further Reading: Fusion Basics

3 Responses to “Nuclear Fusion – a Long Shot?”

  1. Alex Russell

    No risk that I’m aware of of them “putting all their money on this one horse.” Quite the reverse… I am far too frequently seeing nuclear fusion referred to as if it had actually been discredited, or was the province only of cranks – apparently because people have grown up with the line “fusion: your grandfather’s energy of the future” being a safe laugh line. I really worry about us not being able to carry this long-range project all the way through.

    If and when this horse ever comes in, it’ll make a disproportionate difference in our options and in the state of our trade-offs, even assuming that the full array of other energy sources have already come to fruition. We could use it.

    Reply
  2. Drake

    Fusion is all very interesting and worth spending money on but the benefits will be things that were not anticipated. There are already some more advanced fission reactors that will not be tried because of nuclear energy’s bad reputation. It is possible to run a reactor harvest the decay products and recycle them back into the industry and run reactors virtually without waste. What has the fission industry done thus far but to produce lots of “waste” to be turned into plutonium and armor piercing depleted uranium metal? So while we could solve the world’s problems even with present technology there are a determined group of energy companies and arms producers that need a few problems to make a buck.
    Coal is certainly more dangerous than nuclear energy. Coal ash even contains noteworthy concentrations of radioactive isotopes because of the volume of coal that is burned.

    Reply
  3. myu

    Current methods do produce radioactive waste, due to neutron emission as a result of the particular fuel mixes used in current reactors. Aneutronic fusion is much, much more difficult to achieve, let alone turn an energy profit on. Here’s a wikipedia article on it:
    http://en.wikipedia.org/wiki/Aneutronic_fusion

    All deuterium reactions will be producing significant (>1% of energy) neutrons, with the other fuel mixes being a far cry from the “infinitely abundant, harmless seawater” tagline which gets thrown around a lot.

    If fusion ever does get off the ground, it will be far from the pristine, simplified, ideal picture painted for PR purposes.

    I see the future of energy being less. The majority of energy used in first world countries is just waste, so when people bark about the “desperate need” for more energy, I get furious.

    Reply

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