UK and Canada team up to solve nuclear fusion fuel shortage

The UK and Canada have agreed on a joint research programme to tackle one of the toughest problems facing the nuclear fusion industry – how to produce and process tritium, the incredibly rare hydrogen isotope needed to power future nuclear fusion plants.

Attracted by the promise of a new source of clean, abundant power, governments have ploughed an estimated €20 billion into the ITER prototype fusion plant in the south of France, and private capital has flowed into a recent proliferation of private fusion companies.

But most of these projects, if and when they get up and running, expect to rely on tritium, which is not naturally abundant.

There is perhaps just 25-30kg of tritium in stocks globally, said Stephen Wheeler, executive director of fusion technology at the UK Atomic Energy Authority (UKAEA), and prices range from $30,000-40,000 per gram.

“That is a challenge for fusion going forward,” he said. “A power plant might require up to 10kg for commissioning and start-up.” 

This looming problem of tritium scarcity has driven the UKAEA and Canadian Nuclear Laboratories (CNL) to agree a new partnership this month to hone new ways of generating, recycling and purifying tritium during the fusion process so future plants don’t run out. Joint R&D and staff exchanges are on the agenda.

The fusion industry hopes it can solve the tritium shortage by developing ‘breeding blankets’ which are lithium wraps that will produce tritium when bombarded by the high energy neutrons produced by a fusion reaction.

In other words, once up and running, a fusion reaction – the same process that powers the sun - should produce its own fuel.

Ian Castillo, head of the hydrogen and tritium technologies directorate at CNL, compares the need for tritium to jumpstarting a car battery. “Once it goes, in principle, it goes.”

Unproven process

That’s the theory. In practice, “there is no existing demonstration of a full-sized blanket,” acknowledged Wheeler.

The physics of this process is already proven, said Castillo. Breeding is already done on a much smaller scale to produce tritium to make nuclear weapons more powerful.

But getting a smooth breeding and extraction cycle to continuously power a fusion reaction will be a much bigger headache.  

“What is more challenging is, will you be able to breed it in a way that now you can extract it from the blanket, clean it from all the contaminants it will have, recycle it back, [and] put it back into the reactor at the right temperature, pressure?” he said. The first generation of fusion power plants is likely to face a steep learning curve getting this right, Castillo added.

UKAEA is currently working up two new projects to test out this crucial part of the fusion process. The Lithium Breeding Tritium Innovation (LIBRTI) programme will test out breeder materials, while H3AT will simulate how tritium might be captured, purified, and re-injected into the fusion reaction.

The process of tritium management is so complex that H3AT requires a four-storey complex to process just 100g of the radioactive isotope. Although other tritium processing centres do exist in Japan, the US, Canada and Europe, H3AT is expected to the biggest in the world, said Wheeler.

Critical commodity

Even if the fusion industry can crack tritium breeding and recycling it “will continue to be a very valuable commodity”, said Wheeler. That’s because even a successful tritium breeding process will likely only create a small surplus of the substance, leaving fusion plants to rely on other sources to get started.

That’s where Canada comes in. Right now, the world’s main source of tritium is a particular type of fission plant, the Canada Deuterium Uranium (Candu) reactor.

By coincidence rather than design, these reactors are particularly amenable to harvesting tritium as a byproduct.

Although Canada has built a smattering of these reactors in Romania, South Korea, China, India, Pakistan and Argentina, it hosts the majority of them, and crucially, is the world leader in extracting and processing waste tritium.

Romania has only recently signed a $200 million contract to build a tritium extraction facility for one of its own Candu plants, the first in Europe.

“This is where the synergies come across really quite well,” said Castillo of the UK partnership. “For us, working with the isotopes of hydrogen has been our bread and butter for the last 70 years.”

This could, if fusion takes off, put Canada in a uniquely powerful position as the world’s leading supplier of this fuel.

“It definitely becomes a geopolitical dynamic,” said Castillo.

The Canadian state has also committed to refurbishing many of its Candu reactors, amid broader fears about energy security, allowing them to keep running until the 2070s and hopefully heading off a feared crunch in tritium supply. “It’s a game changer,” Castillo said. “That capacity of tritium production will remain.”

In addition to these existing Canadian reactors, new fission plants could even be built specifically to create more tritium, said Wheeler. “This is a commercial opportunity going forward.”

CNL distributes this tritium globally, although only for peaceful purposes. Asked whether it would continue distributing the isotope to geopolitical competitors – China, for example, which has its own growing private fusion industry – Castillo declined to answer.

Silicon Valley for fusion

In comments that might concern the EU, Castillo said that Canada had chosen to partner with the UK because it is the “Silicon Valley for fusion […] generating a fusion ecosystem, bringing [in] companies and generating the staff”.

The UK had until recently more private fusion start-ups than any EU country, although last year Germany caught up. The US is still comfortably in the lead.

Castillo also points out that UKAEA is the “only credible organisation” that has operated a tokamak fusion reactor, as part of the longstanding Joint European Torus (JET) project near Oxford. Researchers at JET, including from the EU, earlier this month claimed they had broken a new energy record during their most recent experiment.

ITER, meanwhile, is currently not set to create its first plasma reaction until 2025, and even that deadline may slip following pandemic and construction related delays. The UK last year chose to leave full membership of ITER, preferring instead to invest in its own domestic fusion industry.

Working with the UKAEA and ITER is not “mutually exclusive,” stressed Castillo. But Canada is only an associate, rather than a full member of ITER. “To some extent, Canada kind of arrived late to that party. So I don't think we're at the stage of making any further commitments,” he said.

For CNL, the third factor making the UK an attractive partner is its regulatory environment. It recently approved legislation that exempts fusion from the stricter safety rules that surround existing fission plants.

The UK has also announced fusion R&D partnerships with the US, and said it would work with Washington to standardise global regulation of the technology.

“I think that will be very beneficial for Canada to kind of join that lead,” Castillo said.

Still, whether tritium becomes a priceless fuel, turning Canada into a global energy kingmaker, depends on whether and when fusion even works as a technology. There are plenty of sceptics who doubt ambitious private sector timelines to get fusion power into the grid before 2035.

Castillo’s estimate is somewhat longer: he thinks fusion grid power will become a reality in 10-20 years. “I’d like to think that I will see [this happen],” he said.