Microreactor gets site permit at Idaho National Laboratory

If you call a nuclear reactor with 12 60-megawatt (MW) modules a “small” modular reactor, what do you call a reactor with 1.5 MW modules?

In the case of Oklo Inc., it’s called a “microreactor.”

“Micro is even smaller than small,” said Caroline Cochran, chief operating officer of the Sunnyvale, California-based company. “It’s a compact, fast reactor.”

Oklo – named after a region in Africa where a natural reactor was found – recently announced that it had received a Site Use Permit from the U.S. Department of Energy (DOE) to build its Aurora plant at Idaho National Laboratory, which CEO Jacob DeWitte called “one of the jewels in America’s research and development complex.”

“The site use permit is an important step toward commercializing advanced fission technologies and is the first issued for a non-light water nuclear power reactor,” the company said in a statement. “The permit outlines the responsibilities for each party regarding use of the site. The site use permit is in effect for the lifetime of the plant and puts a requirement on a maximum licensing timeline for Oklo with the regulator before the start of operation.”

“Oklo has taken a big step toward demonstrating its reactor concept by obtaining a site use permit from the U.S. Department of Energy,” said Ashley Finan, director of the National Reactor Innovation Center at INL. “We look forward to collaborating with Oklo as it licenses, constructs and operates its first reactor.”

Once completed, the teeny tiny reactor will be able to bring power to areas that don’t currently have access to electrical transmission and which predominantly rely on diesel fuel, such as towns, communities and industrial sites in Alaska, island areas, Canada and even parts of the Western U.S., DeWitte said.

Because such sites require frequent refueling with large shipments of diesel fuel, interruptions can have serious consequences, DeWitte said.

“In the dead of winter, that’s challenging,” he said. “We can bring something that’s clean, affordable, reliable and with a greater sense of energy security than what the areas are reliant on.”

Each reactor is expected to have 20 years’ worth of fuel in it, DeWitte said.

“At the end of 20 years, you can refuel it or refurbish it,” as well as decommission it, he said. “It’s a big deal for places that have to refuel every week.”

The reactor is intended to offer power at a price point competitive with what those regions are paying now, he added. For example, the company is going to be looking at recycling nuclear fuel at some point with its INL unit, Cochran said.

Beyond that, the unit could power areas of the developing world as well as the more remote regions, DeWitte said.

“We’re obviously targeting those areas initially, but if you look at the developing world, it’s growing microgrid by microgrid,” he said. “It’s very well suited to have a system of this size.”

With advances in technology, materials, modeling and simulation, it’s cheaper than ever to design new reactor technology, he said.

Because the reactor is small, it also requires fewer people to staff it, DeWitte said. Currently, the company itself – which started in 2013 in Cambridge, Massachusetts, and moved to the Bay Area in 2015 – has more than 30 people on staff.

“We’ll be growing pretty steadily over the course of the next few months,” he said. “We love Cambridge, but it had a different base and a different style of approaching startups.”

Oklo said it has been engaged in pre-application activities with the U.S. Nuclear Regulatory Commission (NRC) since 2016 for the Aurora design and is preparing to submit its first license application to NRC, which will include preparation of an Environmental Impact Statement, the company said. It first entered into a Memorandum of Understanding with the DOE in 2017 and was the first company to complete the new INL site permit application process that was set up in 2018.