Harnessing energy from nuclear fusion could be critical in the shift towards a decarbonized global energy system. As issues of climate change and energy security are becoming increasingly important, the promise of an apparently “clean”, “abundant” and “safe” energy source, such as fusion, is ever more appealing.

The fusion industry is growing rapidly and the trope that fusion is “30 years away and always will be” is beginning to lose credibility as the technology advances beyond its experimental stage.

But it’s too easy to generate hype around a seemingly ideal solution to societal challenges and it is possible that the reality of fusion energy may come into tension with the issues it proposes to solve.

Contextualizing this hype and exploring areas where these tensions may arise is critical to ensuring that the technology evolves in an ethically sound way and can provide net societal benefit if it proves viable.

The appeal of a zero-carbon, low-waste, reliable and relatively safe energy source, such as fusion, is obvious. The development of fusion power is set against the background of growing global energy demand in the context of climate change. This all requires a transition to a clean energy system.

It’s widely believed that fusion energy would be able to solve the problems of existing energy sources. It would circumvent the intermittency of renewables, because the supply from solar and wind power is unpredictable, reliant as it is on weather. Fusion also avoids the serious concern of long-lived radioactive waste, safety issues and public concerns around conventional nuclear fission power. It would help reduce the carbon cost and greenhouse gas emissions from fossil fuels.

Fusion energy may also reduce energy security concerns because some of its key resources are abundant. The deuterium fuel used in some fusion processes can be readily extracted from seawater. This would reduce reliance on fuel imports and insulate nations against global market shocks.

But these benefits of fusion power may mask deeper ethical questions around the development of the technology and some potentially detrimental impacts. One of the most obvious instances of such a tension arises over environmental sustainability. This is especially true of the association with climate change mitigation and the reduction of greenhouse gas emissions.

Climate change is an issue that lends itself to the “techno-fix” approach. It can be tempting to avoid making important changes to our behavior because we believe we can depend on technology to fix everything. This is referred to as the “mitigation obstruction” argument.

Considering greenhouse gas emissions and energy demand also raises questions of justice and equity. Energy demand is rapidly growing in certain regions, primarily the global south, that have contributed the least to the current climate crisis. Yet fusion development is overwhelmingly based in the global north. If fusion proves viable, those areas with access to such a transformative technology are not necessarily those who will need it most.

Climate change is a global challenge, and any proposed solution must account for global impact. The context of development must incorporate considerations of global inequity in the deployment of fusion if we are to meet the climate challenge.

There are similar concerns about the materials used for fusion energy. These include some critical minerals, including lithium, tungsten and cobalt. Mining and processing of these minerals emits greenhouse gases. In some cases, mining operations are located on or near the lands of indigenous peoples. The supply chains for these materials are subject to geopolitical tensions, with alliances, collaboration, competition and the potential for monopolies forming.

Mercury is used in the processing of lithium for fusion reactors. Not only is it environmentally damaging and toxic but mainly depends on Chinese production.

The accelerating pace of fusion energy increases the risk of ignoring these potential hazards along the way. Approaching these potential ethical tensions requires systematic thought throughout the development process, from considering the implications of design decisions and materials choices, through to equitable deployment strategies and knowledge sharing.

Access to energy underpins human wellbeing and development and the energy system has deep societal impacts. Failure to engage with the social and ethical challenges of new and emerging technologies in this area would be irresponsible at best, and harmful at worst. This is particularly true when impacts of fusion technology may compound the precise challenges it aims to solve.

Nuclear Fusion

Scientists at Texas A&M University in the U.S. and collaborators at ETH in Switzerland have found an innovative way to obtain lithium-6, a critical component for fusion fuel for some reactor designs. The conventional sourcing method COLEX uses mercury and is banned in the U.S. This prompted scientists to find new ways to source the isotope as the race for unlocking fusion energy accelerates.

Nuclear fusion technology has gathered much attention in recent years as the world seeks cleaner ways to power its economic functions. Decades of research in this area have now reached the point where engineers can replicate reaction conditions that occur in the Sun and attain a net energy gain.

In nuclear fusion, hydrogen isotopes deuterium and tritium are combined to yield helium-3 and lots of energy. Since tritium is radioactive, rare, and expensive to source, fusion facilities have to set up breeder reactors where the isotope is produced by bombarding lithium blankets with neutrons.

Researchers Sarabjit Banerjee and Andrew Ezazi, who were involved with this work said that lithium isotopes, lithium-6, and lithium-7, can both be used for breed tritium, but the reaction with lithium-6 is much more efficient.

Currently, lithium-6 is produced with the COLEX separation process. Liquid mercury is used to isolate it from the commonly occurring isotope lithium-7. Since 1963, a U.S.-imposed ban on the use of liquid mercury due to pollution concerns means that the country cannot produce lithium-6 anymore.

Since then, the U.S. has been operating with a steadily diminishing stockpile of lithium-6 maintained at the Oak Ridge National Laboratory (ORNL).

Banerjee explained in the email, “There is no publicly available information on the stockpiles of 6Li that the United States maintains. It is a closely guarded secret as it is tied to the ability to produce thermonuclear warheads and the amount of said weapons. However, if nuclear fusion were to become a reality, plants would need tons/day of lithium-6.”

Banerjee and his team discovered a mercury-free approach to isolating lithium-6 while working on a project to clean “produced water” in West Texas.

During oil and gas drilling, groundwater that rises to the surface must be cleaned before it is pumped back down. Using a cement membrane, the researchers were able to filter out silt and residual oil but found that the wastewater still had high lithium levels. This was a result of the lithium-binding capabilities of zeta-vanadium oxide (V2O5). V2O5 is lab-synthesized inorganic material.

Banerjee added in the email, “We found that zeta-V2O5 is indeed a highly selective host for Li-ion insertion and we could capture lithium even though the hypersaline wastewater had many orders of magnitude more sodium-, magnesium-, and calcium-ions. The researchers tested the specificity of the material between lithium-6 and lithium-7 and found that it was useful in enriching the lithium-6 isotope.”

The integration of lithium ions into the zeta-V2O5 changes its color from bright yellow to dark olive green, allowing the isolation to be monitored visually. A single electrochemical cycle enriches lithium by five and seven tenths’ percent. Thirty percent enrichment is a minimum requirement for fusion fuel. This can be achieved by reusing the membrane twenty-five times.

Banerjee said, “Zeta-V2O5 is not expensive to produce, and in fact is now commercially available from a startup company. The material can be repeatedly cycled with no loss in selectivity – in fact it was explicitly designed this way. While we have demonstrated proof-of-concept, with a sufficient number of loops, we expect to get to ninety percent enriched lithium-6 within forty cycles.”

The team is currently working to scale their method to an industrial level. Banerjee said in a press release, “I think there’s a lot of interest in nuclear fusion as the ultimate solution for clean energy. We’re hoping to get some support to build this into a practicable solution.”

Texas A&M