Silex raises $81M to advance laser enrichment of nuclear fuel

28 Feb 2023

Australian company says latest funding boost will enable it to accelerate pilot scheme development and commercialization.

Silex Systems, the Australian company working on laser separation of chemical isotopes, says it has raised AUS$120 million (US$81 million) equity funding that should enable it to accelerate commercialization for the nuclear industry.

The firm, headquartered near Sydney at Australia's Nuclear Science and Technology Organisation (ANSTO), has been collaborating with US-based Global Laser Enrichment (GLE) - a joint venture involving Silex and uranium producer Cameco - for several years.

And the funding comes just a few months after Silex completed what it described as a "pivotal" eight-month test program on the first module of full-scale laser technology that would be needed by GLE, also its exclusive licensee.

Commenting on the equity raise Silex’s CEO Michael Goldsworthy described the financial support as “an exciting and transformational juncture” in the firm’s progress.

“This capital underpins a highly value-accretive acceleration in our various technology commercialization activities, at a time of increasing impetus to improve the security of the global nuclear fuel supply chain and to support a smooth transition toward decarbonization,” he added.

Geopolitical momentum
Aside from advancing the uranium application, Silex says that the new funding will also help it further develop two other potential uses of the technology - separating different forms of silicon for quantum computing, and radioactive isotopes for nuclear medicine.

But the nuclear fuel industry has always presented the most compelling commercial opportunity for the laser separation concept, even more so since Russia’s invasion of Ukraine.

In a report last year Silex pointed out that the US nuclear industry typically imports around one-fifth of its enriched uranium fuel requirements from Russia, with similar levels of reliance in other parts of the Western nuclear industry.

At the same time, efforts in Europe to both reduce reliance on Russian gas and move away from fossil fuels in general have sparked renewed interest in nuclear energy across the continent.

In a new “operational update” issued shortly before announcing the new funding, Silex stated: “We believe Western nuclear fuel markets will undergo a fundamental realignment over the next 12-24 months towards a more resilient and sustainable footing, with the aim of becoming less dependent on, or free of, reliance on Russian and other state-owned nuclear fuel suppliers.

“We believe this realignment could endure for decades, given the renewed focus on long-term energy security.”

Commercial target
In the same update, the firm reported that it and GLE were currently focused on construction of full-scale laser and separator equipment to be deployed in GLE’s “test loop” facility in Wilmington, North Carolina, with a commercial-scale pilot demonstration expected as early as 2024.

The first commercial-scale laser system module is now said to be installed and commissioned, with construction and integration of the pilot-scale equipment currently on track to be completed around the end of this year.

Those recent geopolitical developments prompted Silex and Cameco to re-assess GLE’s prospective timeline, which had previously envisaged commercialization by 2030.

“With evolving market conditions providing strong support for acceleration, any decision will be considered in light of a number of factors, including the level of support available from various government and industry initiatives,” said the firm ahead of the funding deal.

“Acceleration could involve targeting completion of the pilot demonstration program as early as mid-2024, with a view to commencing commercial operations as early as 2027, depending on market demand and other factors.”

Among the options being looked at are bringing forward a commercial feasibility assessment and licensing activities.

As with uranium, Russia supplies much of the world’s so-called “zero-spin” silicon (ZS-Si) material, using conventional centrifuge technology to separate it from standard silicon. The enriched form of silicon is expected to become critical for processor chips used in quantum computing applications.

“The Russian invasion of Ukraine has disrupted this source of supply, which has given rise to some urgency in establishing alternative supply,” says Silex. The firm anticipates that successful completion of its ZS-Si project would enable it to provide a secure and resilient alternative source of enriched silicon to users around the world.

Laser isotope separation
Co-invented by Goldsworthy himself, the laser separation technique works on the principle that output wavelengths can be tuned precisely to the different absorption lines of uranium compounds featuring different isotopes of the radioactive element.

Some of those absorption lines are close to the output wavelengths of carbon dioxide lasers, which can be adapted to resonate with one isotope or another and so initiate the separation process.

There are various ways in which the laser approach could be applied. The likely first application would be to “re-enrich” depleted uranium “tails” of the material from US stockpiles that have built up over several decades. These stockpiles are thought to contain 0.2-0.5 per cent ²³⁵U.

That recycled uranium could then be sold back into the market, before undergoing further re-enrichment to reach the much higher ²³⁵U concentrations needed by nuclear reactors (around 5 per cent ²³⁵U).

Although the laser separation idea is decades old, it has never been commercialized - partly due to fears that the enrichment technology could get into the hands of hostile regimes.

Because laser enrichment facilities could be built in much smaller facilities than conventional centrifuge plants, any proliferation of the technique would be more difficult to police.