Nuclear reactors are definitely powerful, but they also produce quite a lot of problematic, radioactive waste. A new Silicon Valley startup plans to change that through the introduction of small-scale reactors that run on waste from their conventional peers.

The startup Oklo plans to give us a reliable and cost-effective source of power while also solving the issue of radioactive waste, which needs to be stored and managed in particular conditions for hundreds of thousands of years. Their solution is to reuse the waste in autonomous reactors that don’t try to slow down the nuclear decay of the material. Effectively, such a reactor would be able to extract more power from fuel that has already been spent, giving us a use for the processes that happen naturally in a radioactive fuel dump, instead of letting them waste away as radioactive pollution.

No wasting power

“What we’ve done is take waste that you have to think about managing for 100,000 or a million years … and now changed it into a form where you think about it for a few hundred, maybe thousands of years,” Oklo’s co-founder Jacob DeWitte told CNBC.

If you’ve read our piece about nuclear reactors, you’ll know that their main purpose is to draw out the physical processes taking place within them as much as possible. This prevents the fuel from turning into a bomb — very nice — but also limits how much power can be extracted from it — not so nice.

Oklo’s plan is to use small-scale reactors that don’t use water or any other medium around the reaction chamber, mediums which work to slow down the neutrons released from the fuel. This would make them overall more efficient and allow the reactors to extract energy even from spent fuel rods. This approach wouldn’t work in a traditional reactor, however, because fresh fuel is too energetic, and would explode.

In order to keep everything cost-effective, the startup envisions their design to be autonomous, require no human supervision, and be quite small-scale. They would not provide nearly as much energy as a traditional reactor, but would still be enough to power an industrial site, a campus, or a whole company.

Their project started in 2013, with the company spending the last seven years trying to get access to nuclear waste to demonstrate their technology. Oklo was established in 2013 and spent the next seven years getting access to nuclear waste to demonstrate its technology. In 2019, the startup unveiled its plans for its microreactor with integrated solar panels, churning out 1.5 megawatts (MW) of power. Each one, it says, can be built in a year’s time.

The reactors run on spent fuel that’s meant for disposal, and each batch of radioactive waste can power the small-scale reactor for 20 years, according to the startup. In the end, the material they output is still radioactive, but to a much lesser extent than what goes in. This double-spent material will then be vitrified (turned to glass) and buried underground, just like typical nuclear waste.

Oklo is still awaiting a license to build its first microreactor, but the idea of an unsupervised nuclear device is definitely not something regulators will be keen on, no matter how cost-efficient it might be. Exactly where this story will go is still quite undecided, but it is exciting that we have this technology on hand.

Even if the microreactors don’t end up the way Oklo envisaged them initially, they could provide a great way for us to handle nuclear waste going forward. We could significantly slash the radiation our waste produces and the time it remains active after churning it through such a microreactor, and we’d get some energy out of it to boot.