Gates' nuclear start-up fuelled by $35m in fresh funding

An advanced form of nuclear reactor that could one day provide up to 100 years of carbon-free energy while effectively processing its own waste inched a step closer to reality yesterday, when a secretive US start-up working on the technology announced that it has raised an additional $35m (£23.7m) in funding.

Seattle-based Terrapower came to prominence earlier this year when Microsoft chairman Bill Gates revealed he was backing the company's plans to develop a travelling wave reactor.

Gates has subsequently touted the technology as a potential game changer in the race to develop low-carbon energy supplies, insisting that it would prove more reliable than wind and solar power while also dealing with the radioactive waste that has always overshadowed conventional nuclear reactors.

The technology is designed to use up to 99 per cent of the depleted uranium produced by conventional reactors as fuel, reducing reliance on enriched uranium and drastically limiting the amount of radioactive waste that is produced.

Now Gates has reportedly joined a second $35m funding round for the company alongside venture capital firms Charles River Ventures (CRV) and Khosla Ventures.

In an interview with Reuters, Izhar Armony, general partner at CRV, confirmed that more cash had been pumped into Terrapower to support its ongoing R&D efforts.

"We have been an investor since it was just an invention, an idea," he told the news agency. "The company has had great progress and we felt it is time to put more wood behind the arrow, so to speak, to really allow them to accelerate development."

Echoing Gates' prediction that it could take up to a decade to develop a demonstration plant, Armony admitted that the company remained "a very lab-stage and simulation-stage" firm.

However, interest in the concept of travelling wave reactors is increasing and the raising of $35m by such an early-stage company is likely to be hailed as a major endorsement of its technology.

There were also reports earlier this year that the firm – which was originally spun off from Washington-based incubator Intellectual Ventures – has already attracted interest from the nuclear energy industry, with the Japanese giant having had talks about working on a demonstration project.