The Chinese reactor did not produce electricity. It did not even carry out a fusion reaction. The technology has not yet reached that stage. However, the reactor managed to maintain plasma in a steady state of confinement for a long time, longer than it had previously been possible. This itself was a major step forward towards the dream of realising a fusion-based nuclear reactor in the near future.

Extreme conditions

Fusion reactions require very high temperatures, hundreds of millions of degrees Celsius — higher than the temperatures in the Sun’s core.

At such high temperatures, matter exists only in the plasma state, in which atoms get split into positively and negatively charged particles. But such hot plasma cannot be handled by or contained in any material.

Within the reactor, this plasma needs to be kept suspended in a confined space, surrounded by very strong magnetic fields acting as walls.

Charged particles respond to magnetic fields, and this property is used to guide the flow of plasma within an enclosed space, separated from any matter. This condition, necessary for facilitating fusion reactions, is extremely delicate and unstable, with the tiniest of changes in the magnetic field disturbing the whole set-up. Scientists have not been able to maintain these conditions for longer than a few seconds.

That is why the achievement of the Experimental Advanced Superconducting Tokamak (EAST) reactor, located at the Institute of Plasma Physics in Anhui province in eastern China, is being seen as so important. It is a significant improvement on this reactor’s previous record of a little over 400 seconds achieved in 2023.

Real-life electricity-generating reactors would require this state to be maintained for hours, even days, at a stretch. Only then would continuous operations be possible, like current nuclear reactors which are based on fission technology.

Energy source of future

Fusion technology has been under development for more than 70 years but progress has been slow. Even the optimistic forecasts, at least till a few years ago, suggested a functional fusion reactor, producing electricity at a commercial scale, would not be realised before 2050.

For this reason, none of the global energy transition pathways for a net-zero world in 2050, or 2070, factor in the potential of fusion electricity. Each one of those pathways, incidentally, is heavily dependent on the success of several other uncertain technologies such as carbon sequestration and carbon removal, whose technical and economic viability remain under doubt.

However, the promise of fusion energy is alluring. If, and when, it comes through, other sources of alternative clean energy being explored, like solar or wind, to tackle the climate crisis are likely to become peripheral or even redundant.

The fusion process produces far greater amounts of energy than any other source — one gram of fuel can yield as much energy as burning about eight tonnes of coal. It uses cheap input materials, available in almost limitless supply (deuterium and tritium, two heavier isotopes of hydrogen that are used as fuel, are easily available in nature), has a zero emission footprint, and can be set up and operated almost anywhere. Unlike the fission process, it does not leave dangerous nuclear waste.

Recent breakthroughs

In the last few years, fusion research has produced a string of breakthroughs. In December 2021, the United Kingdom-based JET laboratory set a new record in the amount of energy produced through fusion. It produced about 12 MW of electricity for five seconds, enough to cater to the demands of about 10,000 homes for that period of time.

A year later, a reactor in the United States achieved a net gain in energy for the first time. The extreme conditions needed in a fusion reactor require a very large amount of input energy. Fusion would be viable only if the output energy is significantly larger. The performance of this US reactor has improved since then. Last year, researchers at MIT said they had developed a new material that could better withstand the extreme conditions within the reactor.

The feats of the Chinese EAST reactor, in 2023 and now, are the latest additions to these successes. This week, fresh evidence emerged to show that China was building a large laser-ignited fusion research centre that could also be used to develop thermonuclear weapons, commonly known as hydrogen bombs.

The US facility at the Lawrence Livermore National Laboratory in California, which was the first to produce a net gain in energy in 2022, is based on a similar technology.

Greater optimism

The recent breakthroughs have triggered a big surge in interest, and ambition, for fusion energy, particularly among private companies which have entered the field in a major way. A total of 163 fusion reactors, in about 30 countries, are currently in operation, under construction, or being planned, according to the Fusion Device Information System (FusDIS) database maintained by International Atomic Energy Agency (IAEA).

The Fusion Outlook 2023 report, published by IAEA, said private companies operating in this space had attracted $6.2 billion in investment that year. There were at least 43 such companies operating in more than 10 countries.

Helion, a US-based company backed by tech billionaires Sam Altman and Peter Thiel, has promised to generate 50 MW of electricity by 2028, which will be provided to Microsoft. The company aims to become the first firm to start producing commercial electricity from fusion reactions.

Another US company, Commonwealth Fusion Systems, is collaborating with MIT to generate 400 MW grid-scale electricity by the early 2030s from a plant it is building in Virginia.

ITER

The largest fusion reactor, an international collaborative project called ITER, is coming up in southern France. More than 30 countries are participating with India being one of the seven member countries contributing to the reactor’s construction and research. This project, which has been under development since 2005, is slated to become one of the biggest international science facilities in the world. According to its current timeline, it would begin deuterium-tritium fusion reactions by 2039, producing 500 MW of fusion power.

ITER would not be converting the output heat energy into electricity. But its success is expected to pave the way for other machines to start using fusion energy as a regular source of electricity generation.

Dr Indranil Bandyopadhyay, group leader, Council Support and Knowledge Management, at ITER India, said, “A 15-year timeline for nuclear fusion energy to reach commercial scale is very aggressive but not implausible.”