How nuclear batteries can accelerate the race to fusion power

Fusion power has always been a bit of a contradiction. The fusion part is actually easy in a way. For example, a college student recently built a simple fusion device in his bedroom. However, extracting electricity from a reaction is not easy.

“Fusion reactors that produce electricity, and there are a lot of them, they already exist,” Daniel Velásquez, head of materials science at Avalanche Energy, told TechCrunch. “Fusion reactors that make electricity are better.” That’s where the nascent industry is stuck.

Fusion reactions release huge amounts of energy by fusing two lighter atoms into a heavier one. But harvesting that energy has proven difficult. The most common approach is to heat water and turn a steam turbine, but this approach is not very efficient and at best only uses about 60% of the electricity.

Avalanche Energy believes it can capture more of that energy by developing a new material known as radiation emf. Radiation emfs are similar to photovoltaics (traditional solar panels) in that they use semiconductors to convert radiation into electricity. They’ve been around for a while, but they’re not very effective. Existing radiation power generators are easily damaged by the very radiation they utilize and do not produce as much power.

Today, Avalanche was awarded a $5.2 million contract from DARPA to develop a new radiation power generator, the company exclusively told TechCrunch.

A Pentagon research agency is interested in using the material in a new type of nuclear battery that uses radioactive decay from materials such as polonium to generate electricity. Such devices could help power spacecraft and satellites for several years. It could also be used for more energy-intensive ground military applications for days on end. “Especially in missions where autonomous systems and logistics are a little bit unforgiving,” Velasquez said.

That’s not exactly what Avalanche is aiming for as a company, but the DARPA award aligns with that ambition.

First, both fusion reactions and nuclear batteries produce alpha particles, a type of extremely high-energy radiation that can damage all kinds of equipment, including the walls of a nuclear reactor. Second, Avalanche is developing a tabletop-scale fusion reactor that could replace diesel generators at remote military bases.

If the company can develop new radiation emfs for nuclear batteries, it could potentially apply that knowledge to new reactor components. Such coatings can help trap alpha particles, increasing power production while protecting the reactor. Avalanche also received a $1.25 million award from the U.S. Air Force’s AFWERX laboratory to accelerate materials discovery using computational advances.

Fusion startups are all racing to reach a milestone known as the break-even point. This is known in the scientific world as Q>1. Here, Q is the ratio of the power produced by the fusion reaction to the power required to maintain it. Using these alpha particles to generate electricity could make it easier to realize commercial fusion power generation.

Avalanche isn’t the only company designing reactors that produce alpha particles. If successful, the company could end up supplying its technology to other fusion companies, a trend that is emerging within the industry.