The false promises of nuclear fusion

The problem is not that researchers have achieved a scientific breakthrough by producing energy through nuclear fusion. On the contrary. This progress, if confirmed, should be celebrated.


No. The problem is that when reading the press release announcing the feat carried out at the Lawrence Livermore National Laboratory in California, one wants to tell Hydro-Québec to plan the dismantling of its dams and to the manufacturers of wind turbines to print bankruptcy forms.

We would find ourselves, ladies and gentlemen, “on the cusp of a future that is no longer dependent on fossil fuels, but instead is powered by the new, clean energy of fusion”, says Charles Schumer, leader of the Democratic majority in the US Senate.

The rest of the press release – and that’s all we have at the moment, not a single peer-reviewed scientific article – continues in the same tone.

We talk about a “game-changing event” in our desire to achieve a “zero carbon economy”. We talk about work that “will help us solve the most complex and pressing problems of humanity”.

The problem is in this bloat, this marketing of science. In this link that we make between urgent problems (climate change) and technological solutions that, at best, will emerge in many decades.

It is misleading and irresponsible.

Nuclear fusion is the holy grail of energy production. By fusing hydrogen atoms as is done in the Sun, we get a reaction that releases astronomical amounts of energy.

In principle, the fuel is clean and inexhaustible: hydrogen. And, again in principle, the reaction does not produce radioactive waste, unlike nuclear fission.

Of course it’s dreamy. Research in this direction is necessary and unavoidable.

This week, US researchers announced that they have generated a nuclear fusion reaction that provides more energy than is needed to trigger it. This would indeed be a significant step forward.

But first it will have to be confirmed and replicated.

Then, what we are told is half true. When we look at all the systems involved, we realize that they consume 100 times more energy than they produce.

Before fueling your dishwasher with nuclear fusion, there are still daunting technological challenges to overcome.

We will have to find a way to continuously maintain a reaction that we currently only manage to maintain for a fraction of a second.

It will also be necessary to learn how to manage the plasma used to force the hydrogen atoms to fuse. Since this plasma destroys just about anything it encounters, we have no idea what materials could be used in a possible nuclear fusion reactor. It’s like trying to build a box around the Sun.

Another slight glitch. Nuclear fusion is described as clean and safe. Except that for the moment, it is deuterium and tritium, two isotopes of hydrogen, that are forced to merge.

However, tritium is extremely rare… and radioactive. “There are about 200 grams of tritium all over the planet. And a nuclear fusion reactor would require about 150 kg per year,” says Marcel Lacroix, nuclear engineering expert at the University of Sherbrooke. We can make tritium… but it’s complicated and expensive.

Professor Lacroix also points out that nuclear fusion produces a flux of neutrons which can make the material it encounters radioactive.

Ultimately, it is impossible to know if the adventure will one day prove technically possible, let alone economically viable. Some experts see answers within 50 years; others, by the end of the century.

Meanwhile, the IPCC warns us that if we want to limit global warming to 1.5°C, global GHG emissions must peak by 2025 and be halved by 2030. We are not totally on the right track for that.

Let us applaud scientific advances in nuclear fusion, fine. But let’s stop telling the world that this is the cure for the climate emergency.


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