The “Holy Grail” of clean energy that could clean up our planet is nearer than we think, an international nuclear-fusion conference of more than 100 scientists agreed in Canberra last week.
The first stage towards success was already under way in Europe with an international effort to stabilise a doughnut-shaped plasma (the fourth state of matter) at a temperature of 100 million degrees with a giant version of a microwave oven.
No problems there, the scientists agreed: fusion has no safety problems compared with nuclear fission plants, producing less than a hundredth of radioactivity in incidental processes.
Nuclear fission is our dangerously dirty and accident-prone method of producing energy at the expense of radioactive waste by splitting atoms. Nuclear fusion, on the other hand, is based on fusing the nuclei of two atoms. It produces more energy and is radioactively clean. It produces limitless energy (electric power) from seawater or lithium. Nuclear fusion offers millions of years of energy with virtually no carbon impact. The problem is that, until now, no one has worked out how to do it reliably.
Professor Boyd Blackwell, director of Australia’s Plasma Research Facility, said the great problem of the fusion programme was that magnetic fields could break into chaotic shapes.
When you need a reactor that is economical and can be maintained remotely, then you must have perfect symmetry of the plasma formation. Magnetic fields can break into chaotic shapes, especially when you are trying to make them in a three-dimensional reactor.
We use waves carrying energy to the plasma and make these waves resonate with the plasma particles by choosing the right frequency. The trick is to make a force field which holds the particles in place without letting the heat escape.
The “doughnut” problem was that a perfect formation of its plasma is two-dimensional. The programme has to make it work in a three-dimensional world in practical terms and, said Blackwell, this should be achieved within 20 years after producing 500 million watts from the first-stage machines.
This “serious amount of power” would give development investors confidence in the demonstrator reactors – which will have a potential of developing two to 10 times greater watts capacity. At this stage mass-production of clean and reliable fusion reactors can be expected.
The replacement of the world’s coal-powered and nuclear plants would begin. This would have to be a gradual effect because we now have so many coal-powered plants. So a second stage of perhaps another 20 years to accomplish effective replacements with fusion energy would take place.
What we had to keep in mind, Blackwell said, was this was the biggest pay-off you could imagine in cleaning up our world, with damage causing immense climate-change costs. This is, more or less, free energy from the point of view of fusion power stations in the long-term. The fuel cost is near zero to power stations in the long-term. But creating the machines to use it is not and they will be similar in cost to the already escalating price of producing fossil fuel energy and solar energy.
But eventually the world will achieve freedom from the causes of climate change and the appalling costs of nuclear fission disasters.
The world could then lessen much of the damage already done by cleansing its energy production and, agreed the Canberra conference: the means is in sight. - Sunday Tribune