FUSION
I finished the book about the history of nuclear fusion reactor
research that I've been mentioning lately. The title is "Fusion:
The Search for Endless Energy", by Robin Herman. My copy is the
first edition from 1990, which I picked up from a small bookshop
sometime many years ago, I think before I finished secondary
school. Like so many books, I never got around to reading it
properly until now. There was a second edition published in 2006,
which is still available from Cambridge University Press (for quite
a lot more than the $15 for my second-hand hardcover):
https://www.cambridge.org/au/universitypress/subjects/physics/plasma-physics-and-fusion-physics/fusion-search-endless-energy
The author, who died last year, was a journalist (rather an
unlikely one to cover this topic, if her Wikipedia page is anything
to go by) and as such it's not a technical book. Key scientific
developments are summarised at a level that's easily digested, but
primarily as part of a narrative describing the overall history of
the field. Key individuals in the plasma physics community, and
politics behind the scenes of the experiments, are given as much
focus as that applied to the technology itself. This wider context
explains many of the motivating factors behind fusion's often
unsteady rate of development, and of course the field's unrealised
promises (not to mention occasional mistaken claims) of success.
I think complex technologies are always best understood on top of
the historical narrative of their development. This book explains
that history with ample entertaining anecdotes picked up through
the author's own interviews at a time when scientists from the
first generation of fusion research were still alive to tell their
stories. At times it does ham things up a little, a bit overly
eager to elevate the generally dry world of plasma physics
research, but succeeds at presenting such a complex field in a
highly readable way. It also tries to cover a global perspective,
both sides of the iron curtain, and also peeking into Japanese
research later in the game.
Upon finishing the book, the obvious thing to do is to look into
what's happened in fusion research since 1990. That actually seems
to be an interesting point in time with which to compare the
current state of the science, because in some ways it seems that
everything has changed yet nothing has changed.
Having documented the record-breaking giant Tokamak reactors of the
USA and the EU, TFTR and JET, which nevertheless failed to realise
their scientist's dreams of reaching 'breakeven', the book mentions
the beginnings of the ITER project. With initial design work dating
back to the late 1980s, ITER is still today the fusion community's
one big work-in-progress, possibly nearing completion but also
encountering new delays. In pushing for a giant international
effort, it seems that the scientists unwittingly deprived
themselves of continuing to build up ever bigger Tokamak-based
reactor designs via the national programmes of their individual
countries. In the USA, a successor project to the TFTR reactor at
the Princeton Plasma Physics Laboratory, home of the first US
experiments into fusion reactor design, was never realised at the
same scale. The one commercial company that got into building
fusion reactors during the era covered by the book, General
Atomics, is still running their DIII-D reactor from 1986, while
trying to raise funding to build a new design. The JET reactor in
England is still currently the biggest working fusion reactor, with
efforts recently focused on research to help the ITER project.
The Russian T-series Tokamaks, the origin of the design that now
dominates magnetic fusion research, never caught up to scale of
western designs in the 1980s since their big T-20 reactor project
fell victim to the failing Soviet economy. But their T-15 reactor
has also been upgraded for research contributing to ITER, and
curiously they've also converted it to work as a fusion-fission
hybrid. This is a little-explored, and in many circles unpopular,
branch of fusion reactor development which is surprising to see pop
up at this point.
https://www.iter.org/newsline/152/477
https://www.neimagazine.com/news/newsrussia-launches-t-15md-tokamak-at-the-kurchatov-institute-8757349
The Chinese have also now gone heavily into fusion research, as an
ITER member as well as through construction of various reactors
themselves. They've even pulled an old Stellarator out of the
Australian National University, which seems to have been the only
significant Australian fusion reactor known to the internet, the
Heliac-1, built in the early 90s. So much for aussie fusion then, I
suppose.
https://www.canberratimes.com.au/story/6033331/anu-partner-with-china-on-nuclear-fusion-technology-for-power-supply/
Outside of magnetic fusion, the latest big news has been the
success of the National Ignition Facility (successor to the Nova
facility described in the book) at surpassing breakeven - getting a
fusion reaction to release more energy than is put in to start it.
While ITER seems to have stolen the focus of magnetic fusion
funding away from national projects, the NIF and laser fusion has
been USA's big national project, bred out of a laser fusion
programme which was still significantly classified at the time of
the book's publication. After initial failure in the 2010s, NIF
finally acheived the 'ignition' that their facility was named for
in 2021, then 'breakeven' last December and again last month.
The trouble with this is that 'breakeven' was really intended as an
interim target for magnetic fusion, a milestone that the big 1980s
Tokamaks were hoped to reach, from which to plot a path towards a
practical fusion power plant design. The difference with laser
fusion is that whereas a magnetic fusion power plant is expected to
reach this point of energy production through one massive injection
of energy into a gas and then have the reaction sustain itself
afterwards, a laser fusion reaction is one flash in the pan which
actually blows the environment for the reaction (the fuel pellet)
apart in the instant that it happens. Whereas magnetic fusion is
often described as akin to putting the sun in a box, I think laser
fusion is more akin to detonating a mini H-bomb in a box. Indeed
this has really been the force behind laser fusion research from
the start: studying the behaviour of fusion reactions as they
happen in bombs in order to advance the USA's nuclear weapons
research. The LIFE programme to develop laser fusion into a
power-producing proposition has already been abandoned. NIF's long
reset times, massive laser energy losses excluded from the
breakeven calculation (vastly dwarfing actual energy production),
and the extremely expensive (some even made with diamond)
ultra-precise fuel pellets that are destroyed in each test, make it
look a world away from something that could economically produce
electricity.
But perhaps what's most different in the fusion field compared to
in the 1990s is that these national, and now international, fusion
programmes are no longer the only game in town. While General
Atomics was the only private company to do significant practical
research over the period covered by the book, there currently seems
to be an explosion of fusion start-ups building all sorts of
reactor designs, following both old avenues abandoned by the
national programmes of the past, and completely new concepts. The
same enthusiasm for green energy solutions that encouraged
governments to back constructing the big Tokamaks following the
1970s oil crisis, before promptly losing interest later in the 80s,
has now gripped private investors. With the resulting new companies
promising much shorter paths to fusion than the slow road that's
being laid by ITER.
While it's great that many alternative avenues to fusion are now
being investigated as part of the current green energy race, the
fact that it's being done in the private sector has some
disadvantages too. It means that some of the walls of secrecy that
were first taken down back in the late 1950s when fusion research
was declassified by the major governments, are now being errected
again for the sake of protecting intellectual property. Much of the
reaearch and technology is being kept under wraps by companies
afraid of helping their competitors to reach the fusion goal first.
The result is lots of glossy 3D-rendered animations and sales
pitches, but frustratingly little information with which one can
separate fact from hype. Many machines have been built by these
start-ups in the 2010s, with their creators often claiming that
they've learnt enough from those tests already to build a working
fusion generator within the decade. Given that venture capitalists
are little interested in investments that take much longer to pay
off, perhaps that's no wonder. The promised results of public
fusion projects seem eternally to be 20-30 years away, but perhaps
private fusion will forever be 5-10.
- The Free Thinker
