Is nuclear fusion the answer?
It’s about building fusion reactors that deliver unlimited energy with no nuclear waste or carbon emissions. Here is everything you need to know:
What is fusion
Nuclear fusion is the nuclear reaction that drives the sun and all stars. It occurs when two nuclei of a light element like hydrogen collide at colossal speed, forcing them to fuse. The remaining mass is converted into enormous amounts of energy using Einstein’s formula E = mc2. Unlike fission, in which atoms are split, fusion requires small amounts of ordinary fuel – the amount of hydrogen in a glass of water could be enough energy for a person’s life – and doesn’t generate much radioactive waste, which is why they are called “” referred to as. the holy grail for the future of nuclear power. Proponents believe that fusion reactors could solve the climate crisis by delivering inexhaustible energy with no emissions and no chance of core meltdown. However, the challenge of creating fusion reactions is enormous: Scientists and engineers essentially need to create a small star. Hydrogen needs to be on 100 million degrees Celsius – six times hotter than the core of the sun. At this temperature, hydrogen is no longer a gas, but a plasma, a soupy mixture of charged particles that is incredibly difficult to hold. Scientists have tried to create the plasma with a tokamak, a donut-shaped structure with an extremely strong magnetic field, but so far have only been successful for seconds.
Why try such an achievement?
With the climate crisis worsening, President Biden has pledged to eliminate all greenhouse gas emissions from the electricity sector by 2035. Solar, wind and hydropower will play an important role, but these technologies are not feasible everywhere, including Biden’s energy plan, which includes nuclear technologies. One possibility is to build mini fission reactors, which would be much safer and cheaper to manufacture than the current generation of aging nuclear power plants. However, nuclear fusion would be far superior as it avoids the huge piles of radioactive waste that must be stored for thousands of years. Governments around the world are investing billions in research, as are private investment projects such as Breakthrough Energy Ventures, launched by Microsoft founder Bill Gates.
Where does the research stand?
The largest project is ITER, a tokamak the size of 60 football fields that is under construction in France and is expected to be operational in 2035. ITER, which means “the way” in Latin and originally stood for International Thermonuclear Experimental Reactor, is a joint effort by the European Union, the USA, Great Britain, China, Russia, Japan, India and South Korea. Preliminary tests are carried out in a model facility in Great Britain. Several retired fusion physicists, including Ernesto Mazzucato and Daniel Jassby of Princeton’s Plasma Physics Lab, have described ITER as a bureaucrat-run boondoggle that is likely to waste its potential cost of up to $ 65 billion.
How far is it from success?
The joke in the industry is that every year a working merger is supposed to be 25 years away. Proponents, however, claim that it could actually only be five to ten years before a fusion reactor could actually deliver more power than it consumes thanks to major technological breakthroughs. Materials are now available that can withstand or prevent erosion of the container around the plasma, including steel with reduced activation and tungsten. Superconducting high-temperature magnets have been developed that generate considerably stronger magnetic fields and can be kept cool by using cheap and abundant liquid nitrogen instead of the rare liquid helium. This means that fusion reactors can be developed that are much smaller than ITER.
Who is working on it?
One company, Commonwealth Fusion Systems, spun off from MIT in 2017 and is building a tokamak the size of a tennis court that will cost a fraction of the ITER with private capital of around $ 250 million. A prototype of a reactor that can generate around 270 megawatts and is sufficient to supply 100,000 households with electricity is to be commissioned by 2025. A UK company, First Light Fusion, uses an entirely different method of limiting plasma, inspired by a crustacean called gun shrimp. When this shrimp snaps its claw to stun prey, it creates bubbles that collapse to such an extent that the vapor inside briefly turns into plasma at 4,700 degrees Celsius. This mini-explosion creates so much noise that pistol shrimp colonies disrupt the submarine sonar. Using a similar technique, First Light hopes to initiate its first fusion reaction this year and demonstrate a net energy gain by 2024.
Will these efforts pay off?
Lockheed Martin’s example is sobering. This giant defense and energy company has been working hard on the merger for years, making slow progress. South Korea is furthest ahead, but even the National Fusion Research Institute only managed to keep the plasma at 100 million degrees Celsius for 20 seconds. Still, the researchers agree that fusion is within reach. “I don’t think it goes too far to say the merger has its kitty hawk moment,” Commonwealth co-founder Martin Greenwald told the Institute of Electrical and Electronic Engineers. “We don’t have a 747, but we fly.”
An alternative: small fission reactors
State-of-the-art energy companies – including Bill Gates’ TerraPower – are working on mini-fission reactors called small modular reactors, or SMRs. Last fall, the Nuclear Regulatory Commission first approved such a device, announcing a design by Oregon-based NuScale Power to generate 50 megawatts of electricity. That’s a lot less than a conventional reactor’s 1,000 MW, but utilities could combine up to 12 MW to provide electricity to a medium-sized city. Some SMR companies use molten salt as a coolant instead of water, with no pumps and valves that can break. Proponents say that such a reactor cannot melt, so it does not require a large evacuation zone. However, critics point out that even small fission reactors cost billions to build and they still produce radioactive waste that has to be stored somewhere at high cost and risk. “Although SMRs have a lower cost of capital per unit,” says the International Atomic Energy Agency, “their economic competitiveness has yet to be demonstrated.”
This article was first published in the latest issue of The Week magazine. If you’d like to read more of it, you can try six risk-free editions of the magazine here.