New thrust to nuclear fusion

The new brag in nuclear fusion is about how long one can make the plasma last, and the Chinese have been ahead of this game for a while now. In February, the French WEST tokamak nuclear fusion reactor announced that it has maintained a steady loop of burning plasma for a record 1,337 seconds, beating the Chinese EAST’s previous 1,066-second benchmark set in January 2025 by over 25 per cent.

WEST stands for Tungsten (chemical symbol W) Environment in Steady-state Tokamak and EAST stands for Experimental Advanced Superconducting Tokamak. This achievement is seen as a major leap forward but not necessarily a sign that commercial fusion is around the corner. While France and other Western powers have been working on this technology for a while, China’s interest in nuclear fusion is from an environmental perspective, for energy independence and technological leadership. China sees nuclear fusion as a crucial technology for the 21st century and is outspending the United States in fusion research. While it is not impossible for the US to increase its spending, the Chinese have 10 times the number of PhDs in fusion science and engineering compared to the US and many believe that China may be racing ahead in this sphere due to this.

If it is so limitless and clean, why are there no commercially available nuclear fusion reactors in the world today? That is because it is hard to replicate what the stars do. Atoms naturally repel each other due to the electromagnetic force between their positively charged nuclei. One may remember playing with magnets and how hard it is to push the north poles of magnets together; so a huge amount of energy is required to push these atoms together. Instead of trying to force two atoms at a time to fuse, scientists create a plasma which is essentially a cloud of charged ions. By increasing the temperature of the plasma, the ions are made to move faster and by doing so overcome the electromagnetic repulsion.

Since the temperature required to make this happen is over 100 million degrees centigrade, a challenge in itself, confining the plasma at that temperature is an even bigger challenge. There is no material that can withstand these temperatures and therefore, one needs to confine the plasma using magnetic fields.

There are a few other hurdles that need to be overcome before we can see commercial nuclear fusion energy made available. Current attempts at nuclear fusion involve fusing isotopes of hydrogen – deuterium and tritium. While deuterium is available in plenty, tritium supply on earth is limited and its shortage is being handled through tritium bleeding blankets within the reactor. However, optimising blanket design and alternate tritium production methods are active areas of research. Developing materials that can withstand the extreme conditions within the fusion reactors has led to promising results with tungsten and beryllium, but this is an ongoing process.

High costs, emerging players

The cost of setting up nuclear fusion reactors is also extremely high. Many milestones have been crossed
in the recent past with net energy gain from nuclear fusion only recently achieved at the Lawrence Liverpool Laboratories in the US. Even this has had only a net energy gain (energy output over energy input) Q of around 2 while commercial reactors will require a Q of 10 or more.

The recent budget speech by Nirmala Sitharaman too emphasised the importance of nuclear energy and promised Rs 20,000 crore towards this end. There was no mention of nuclear fusion in this speech but India has been involved in nuclear fusion research for decades. India set up the Institute for Plasma Research in 1986 and created ADITYA as its first tokamak in 1989. It set up a tokamak in 2013 and there is another expected in 2027.

While nuclear fusion research in the 20th century was restricted to government and inter-governmental laboratories like JET and ITER, the last decade has seen many private companies emerging. Investors like Bill Gates, Elon Musk and Jeff Bezos have been investing and betting big on nuclear fusion.

Fusion research is proceeding at a furious pace but despite recent achievements, it does not appear to help reduce the world’s dependence on fossil fuels before climate change becomes irreversible. Until nuclear fusion is made available commercially and at scale, the world still needs to reduce energy consumption and invest in other renewable energy sources.

(The writer is a senior scholar at the Takshashila Institution, Bengaluru)