Compact Fusion: Are the Energy Equations About to Change?

Compact Fusion: Are the Energy Equations About to Change?

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Institute for Defense Studies and Analysis Atul Pant | January 10, 2018

Power generation through fusion reaction has been one of the most attractive fields of nuclear research and has consequently seen considerable investment since the middle of the last century. While the world has been awaiting a breakthrough in an affordable and clean power source for long, nuclear fusion has always been taunted, since the 1950s, as the energy source that was 50 years away from commercial availability and would always remain so. In recent years, however, there has been some noises about getting very close to the first real goals of harnessing this energy, i.e., working prototypes of fusion reactors. Advanced technologies and supercomputing have remarkably accelerated the pace of R&D in this field, which has probably led to the recent confident claims.

In nuclear fusion, various isotopes of hydrogen are fused together to form a new element, helium. In the process, a small amount of matter is converted into heat energy, as in the case of nuclear fission. This energy is enormous and could be harnessed. But the temperature required for nuclear fusion to occur is in the range of 13 million degrees centigrade. No material can withstand such high temperatures. Hydrogen fusion experiments are therefore presently being carried out in apparatuses called ‘Tokamaks’ (toroidal plasma chambers), where the hydrogen in extremely hot plasma form is fused together while being suspended away from the walls of the apparatus using extremely strong magnetic fields.

The problems in achieving successful nuclear fusion have mainly related to sustaining the reaction for long durations and plasma containment.1 The moment the plasma comes into contact with any other material in the tokamak, it immediately loses heat and the temperature required to be maintained comes down drastically, stopping the reaction. At present, it has been possible to stably hold the plasma in the tokamak only for a few seconds or at best a few minutes. Large amounts of input energy are also required for the experimental apparatus to worknd to sufficiently raise the temperature of the plasma for the fusion reaction to start. In all the experimentation conducted till date, it has not proved possible to obtain a higher output of fusion energy than the input energy. The best output to input energy ratio has been 65 per cent.2 For fusion to become a viable source of energy generation, the reaction will have to be sustained for long durations and output energy will have to be many times greater than input energy.

In 2013, Lockheed Martin’s Skunk Works revealed experimental work on a new high-beta reactor design concept, a ‘compact fusion reactor’, for commercial fusion power.3 ‘Skunk Works’ is the official pseudonym for Lockheed Martin’s Advanced Development Programs (ADP), formerly called Lockheed Advanced Development Projects. When the project was initiated, the aim was to achieve a working prototype compact fusion reactor in five years (2018), make it available for military applications in ten years (2022-23) and make it commercially viable in 20 years. Further, the apparatus to be developed was to be as compact as to fit on the back of a truck and produce energy equivalent to a 100 MW power plant, sufficient for the energy needs of a small city of 100,000 people. Use of the term ‘high-beta’ is indicative of the high ratio of plasma pressure to magnetic pressure, loosely indicating high efficiency. If successful, compact fusion could be a revolutionary invention.

The compact fusion reactor will use deuterium and tritium isotopes of hydrogen as fuel (as in other tokomaks), and a neutron source for the reaction.4 The reactor being researched on is just about two metres long and one meter in diameter (called linear compact reactors) as against tokamaks that are comparatively huge in size. The plasma containment concept being worked on is new and very different from tokamaks, with supposedly better results. The energy produced in the reactor would be in the form of heat which would be harnessed through a turbine as in a fission reactor. But unlike in the case of fission reactors, the by-products of the fusion reactor would be non-radioactive Helium and neutrons. The neutrons would be absorbed by a Lithium blanket on the walls of the reactor, which would produce more tritium –found only in rare quantities on earth.5

Skunk Works has, however, been secretive about the degree of success of the experiment so far and not released any data to prove its claims. It has been conducting briefings and presenting the research concept in many forums, and projecting the venture as a practical solution to all of the world’s energy problems. Many in the scientific community have, however, been terming their claims as outlandish and impractical. But others have preferred to go with Skunk Works’ optimism based on the reputation of the company and is earlier achievements, which include the designing of a number of state-of-the-art aircraft like the U-2, SR-71 Blackbird, F-117 Nighthawk, F-22 Raptor, and the F-35 Lightning II. But the degree of success achieved so far cannot be judged with any certainty at present because of the company’s policy of closely guarding data and outcomes.

Another compact fusion experiment proclaiming success in the near future is the Spherical Tokamak-40 (ST-40) experiment by Tokamak Energy, a private company in the United Kingdom.6 The experiment is on similar lines to Lockheed Martin, albeit with a spherical plasma chamber instead of a cylindrical chamber. This company is also keeping much of the experimental data classified. David Kingham, CEO of Tokamak Energy, has said that ‘The ST40 is a machine that will show fusion temperatures – 100 million degrees – are possible in compact, cost-effective reactors. This will allow fusion power to be achieved in years, not decades.’ And he added that, ‘We are already half-way to the goal of fusion energy; with hard work, we will deliver fusion power at commercial scale by 2030.’7

Tri Alpha Energy is another US company working on commercial fusion power using linear compact reactors like Lockheed Martin with similar timelines.8 A compact fusion device, Mega Amp Spherical Tokamak (MAST), is also being developed alongside Joint European Torus (JET), to validate the design for fusion power.

Though research is being carried out at almost 200 tokamaks worldwide, including the famous International Thermonuclear Experimental Reactor (ITER), none is envisaging imminent breakthroughs as in the case of compact fusion, even though some successes have been recently achieved in boosting the energy output tenfold by introducing Helium-3 isotopes in the fusion reaction.9 India is also a prominent participant in the ITER programme.

The various claims being made on harnessing fusion energy in a cost-effective manner may give a feeling that the world is approaching a new clean energy era. But such a development is not likely, even if this technology has the potential to take care of all of mankind’s energy needs. All the developed nations have made major investments in various other fields of the energy sector. None of them would allow their investments to be wrecked. The greatest and immediate hit of attaining success in harnessing fusion energy is likely to be on oil prices. For instance, the world saw a bloodbath in the oil market when the US opened up its oil reserves for export recently. Oil prices probably would similarly plummet if and when the fusion experiment succeeds. As such, global oil demand is predicted to see a downtrend beyond 2025.

Even other energy investments such as in wind, solar, coal, etc. could suffer major setbacks. With such a disruptive potential, it can be logically predicted that the technology would be under strict US or UK governmental controls for many years or even decades to follow. None would allow its own established energy businesses to take a sudden hit. The percolation of fusion technology to other nations in all likelihood would, therefore, be at very carefully measured rates for the next two to three decades. Besides, since compact fusion would be solely their creation, Western companies and governments are likely to exploit it for profits for many years to come. The latest National Security Strategy of the US released in December 2017 explicitly mentions the intention of the US to dominate the energy sector and reiterates the continuing role of fossil fuels in the future energy mix, which shows that even if compact fusion energy is achieved, the US would play all the energy resource cards to its advantage.10

Entities working on compact fusion also claim that their technology will avert the major environmental impacts of global warming, expected by 2050.11 The positive climate mitigating impact of such technologies would, however, depend on the economic viability of fusion energy, which, in turn, would depend on the costs of reactors, cost of materials, complexity of technology, access to technology, product patenting, etc. Only time will tell whether these companies allow their inventions to become tools of environmental redemption. Cost effective fusion reactors would be able to provide practically limitless power for all the needs of mankind from domestic to industrial supply to desalination of sea water without environmental degradation and further energize pollution control mechanisms. It is, however, surprising that the World Energy Council has not factored-in any share of fusion energy in future energy scenarios that it has created for 2050. Even the International Energy Agency sees the possibility of energy being produced from fusion reactors only beyond 2050.12

Other facets of this technology are that it is safe and cannot lead to the making of a fusion bomb.13 There would be no danger of accidents similar to Chernobyl as a runaway fusion reaction is intrinsically impossible and any malfunction would result in a rapid shutdown of the plant. Military applications of fusion reactors would probably be limited to powering the energy needs of ships, aircraft and spacecraft only. Interaction of the neutrons, produced as a by-product, with the walls of the reactor is expected to reduce the reactors’ or their components’ life. These would require replacements,14 which, in turn, would give additional controlling power to the manufacturers. The companies engaged in developing this technology have, however, not drawn attention to this aspect. Research being undertaken in other fields of energy storage, especially vis-à-vis battery technology, are also showing encouraging results. High-capacity battery technology would form a perfect partner with compact fusion technology in providing clean energy in the future.

Although fusion does not generate long-lived radioactive products and the unburned gases can be treated on site, there would a short-to-medium term radioactive waste problem due to the activation of structural materials. Some component materials will become radioactive during the lifetime of a reactor due to bombardment with high-energy neutrons, and will eventually become radioactive waste. The quantity of such waste is, however, likely to be insignificantly small. There is also a possible risk of leak of Tritium into the atmosphere. While Tritium is radioactive and can be inhaled, it has a half-life of only 12.3 years and would be used in small amounts and the risk would still be less than from fission reactors.15

India has its own plasma research experimental tokamaks called ‘Aditya’ and SST-1 at the Institute of Plasma Research, Gujarat, for conducting fusion research.16 These have given invaluable experience to Indian scientists because of which they have found a prominent place in the ITER project. India has not ventured into compact fusion research so far. In view of the various recent developments in compact fusion, India also needs to carefully tread forward in the energy sector, especially when getting into long-term contracts for power generation. India’s demand for forthcoming decades is huge, for which there are plans afoot to have major ventures in various energy sectors. These would require heavy investments. If economically produced fusion power becomes mainstream, such investments would prove to be a waste. It would be prudent therefore to keep an eye on developments in this field, conduct technological forecasts of fusion research and revisit future energy plans as needed.

Views expressed are of the author and do not necessarily reflect the views of the IDSA or of the Government of India.