Nobody claims that fusion is 30 years away

This post began life as a digression in the last post, but started to have a life of its own. So why not …

To give an example of what ideologies look like take this slate artice on Fusion Energy.

The critique of fusion energy has a long history and so do the arguments brought forth. It has been stated in the 1980ies that people have been saying for 30 years now (since the 1950ies), that commercial fusion will be viable in 30 years. Today, another 30 years later, the same phrase is still being repeated – even though no such claims have been made in the meantime.

Such claims have been made in good faith in the 1950ies. For a relatively brief time it seemed as though a self-sustaining fusion reaction could be achieved on a modest scale using relatively small equipment, by human standards. In general, it is much easier to develop a technology that requires equipment that can be handled by a human being on a workbench. It allows rapid assembly and modification of equipment. Imagine human beings were the size of rats. Even something as simple such as making a camp fire would become much harder, because the laws of physics dictate that a campfire needs to be at least as big as a rat and preferably larger, just to keep the fire going and to make sure there is enough wood to burn to make the fire last for more than a few minutes. If we were the size of rats, we would need to pile up a huge pyre to get any decent fire going … and even then it would be an ordeal to add more wood to the fire.

Back in the 1950ies, scientists thought that nuclear fusion reactor cores would be roughly as big as the cores of experimental nuclear fission reactors – which came in sizes as small as a football. Small in terms of a human being, easy to fit on a workbench, but about twice as big as a rat. (Of course, the infrastructure surrounding this core was somewhat bigger – but still in roughly human dimensions.)

It turned out in the late 1960ies, that in nuclear fusion, we’re the size of rats. The smallest efficient fusion reactor using the knowledge and technology of the 1960ies, would need to be tens of meters in diameter. Of course, a reactor the size of a sports gym isn’t exactly feasible and even significant improvements would not reduce this to the size of a workbench. With the infamous exception of the General Electric public relations department, people stopped saying that fusion was 30 years away.

Significant improvements did occur, however, in the early 1980ies. A way was found to coerce plasma into a “high confinement mode”, a condition in which the plasma would not lose its energy so easily. Combined with the development of better super conductors in recent years, the minimum size of a feasible reactor could be reduced an order of magnitude. Instead of tens of meters, only a few meters were required.

The sheer size of the reactor, the relatively exotic materials used, lack of experience and political troubles unfortunately conspire to make the development of such reactors a lengthy undertaking. Even relatively minor changes to a reactor of this size take a lot of time to put in place, building a new reactor within less than decade of planning and political bickering in a time of extremely restricted funding is well-nigh unthinkable, all of which makes experience a hard earned luxury.

What gets lost among all the claims of wasting money, however, is the extremely small expenditure even to large projects like ITER compared to what else people are spending money on. The obvious comparison, of course, is the US annual military budget of $700bn. On this scale, the 30 years that ITER will be running and conducting experiments will cost as much as running the US military-industrial complex from January 1st to January 10th this year. Or as much as the London Olympics 2012 – excluding infrastructure investments.

The main reason why there won’t be a working fusion power plant, even for demonstration purposes, in either Europe or the USA in the next 30 years is simple lack of funding. ITER, from its inception in 1985 to the start of construction, took 25 years to get started and it will be 2019 until start of operation. The largest fusion reactor of our time until ITER is finished – the Joint European Torus – took 4 years in planning and 6 years for construction. Less than one third of the time for ITER. Less than one third. And that is the main reason why fusion doesn’t seem to progress. There can be no progress unless experience is put into practice.

During its last true fusion experiment in 1997 (a new one is now planned for 2015) nuclear fusion accounted for 40% of its energy output – 16MW of fusion power. ITER will have 10 times the volume, allowing for better confinement by sheer bulk of plasma, and a 4 times stronger magnetic field, allowing for higher plasma densities as well, which is enough to dispense with additional heating once the reaction has started and rely on heat generated from fusion alone to sustain it.

While it is not as easy as I make it sound – plasma physics is a complicated field that may still have some surprises left – the physics is much less of a problem than the funding. Given that research and development have long been removed from priorities of European and American politics (though not from political speeches), the future of nuclear fusion research is much more likely to be found in Asia … where large projects take less than a quarter century to even get going.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s