Microreactors are the future of mining

Powering a remote zinc mine located roughly 600 miles northwest of Anchorage, Alaska, is a Herculean task.

Governments and industry have taken a particular interest in remote arctic mining locations, not only because of the region's vast mineral resources but also because of shipping routes that are opening through the ice due to climate change.

Still, getting energy to those locations is extremely difficult. First, a tanker must transport diesel fuel to a port on the Arctic Ocean during the few months when the water is free of ice. An unexpected storm can delay fuel shipments, costing a mine thousands of dollars in revenue.

"You have to barge the fuel during your shipping window, store it at the fuel farm and then truck it 70 miles inland daily," said Jennifer Leinart, president of InfoMine USA Inc., a company that provides cost estimating for the mining industry. "The mine is spending 80 cents a kilowatt-hour, at least, to self-generate electricity using diesel generators."

That's six to 10 times the cost of electricity in the Lower 48 states, and a major expense for a mine that uses 460,000 kilowatts to extract and process 20,000 metric tons of ore each day.

As communities around the world work to reduce greenhouse gas emissions, experts have identified a handful of niches that will be especially difficult to decarbonize.

The mining industry is one of these niches, along with remote communities, marine propulsion, and industries such as chemical, concrete, and steel production. Some of these applications require heat as well as electricity, as they are too remote to connect with the electric grid or have energy requirements that make batteries impractical.

Now, researchers at Idaho National Laboratory are exploring how microreactors could help reduce costs for mining operations, which often face the dual challenges of high energy needs and remote locations.

The idea isn't new. Several microreactors were built and deployed during the early years of nuclear energy development, including a 1-megawatt reactor that powered a radar station near Sundance, Wyoming.

Tomorrow's microreactors - small, factory-built, easy-to-move nuclear reactors - are flexible enough to provide both electricity and heat, require little space and are safe to operate. These configurable, transportable "fission batteries" present a carbon-free option for companies looking to reduce carbon emissions.

While the capital costs of a microreactor might be higher than diesel generators, they are cleaner and more reliable, and the cost for the reactor fuel, operations and maintenance would be less than the cost of diesel fuel.

Mining is ripe for microreactors

Experts estimate that mining accounts for between 4% and 7% of worldwide greenhouse gas emissions and around 3.5% of all energy consumed. And yet, the mining industry is essential to meeting climate change goals because it provides the minerals such as lithium, cobalt, and rare-earth elements necessary to produce batteries, wind turbines, solar panels, nuclear reactors and other zero-emissions technologies.

"We're recognizing that mining might be a ripe area for use of these microreactors," said David Shropshire, a nuclear energy economist at INL. "The cost of getting the fossil fuel and storing it is really expensive. Fuel shortages at the mine due to extreme weather are another concern."

Shropshire explores the economics of nuclear mining as part of the INL-led Emerging Energy Markets Analysis initiative.

This initiative is a collaboration among INL, the University of Alaska, Boise State University, Massachusetts Institute of Technology, the University of Michigan, the University of Wyoming, and the University of Utah, and is aimed at helping states and regions transition to clean energy technologies, including nuclear energy.

Microreactors could be a good opportunity for the mining industry, said Halle Cogley, an INL intern who grew up in five different mining towns. Her mother, father and brother still work in the industry.

"A lot of mines are moving toward renewable energy to cut down on emissions, but solar and wind aren't always reliable," she said. "A microreactor could solve those problems."

Electrification

The next generation of simple, reliable microreactors comes as the mining industry explores the benefits of replacing fossil fuel-powered equipment such as excavators and haul trucks with electric alternatives.

Electric mining equipment would not only reduce fuel costs and emissions but also maintenance costs and the need for ventilation in tunnels. Electrifying mines would also improve noise and air quality for workers and help the mine meet environmental regulations.

"It's a perfect storm," Shropshire said. "In the mining industry, there's a general move toward electrification and away from fossil fuels. And there's a lot of interest in using microreactors to generate that electricity."

Additional benefits

Aside from the potential cost savings and the advantages of electric mining equipment, microreactors could provide additional benefits.

For starters, a microreactor could provide heat and electricity for further processing of the ore.

"Microreactors, because they could provide process heat, could be used for secondary ore processing," said Shropshire. "That means the mining company could produce products that are more refined and more valuable."

At the Alaska zinc mine, ore goes through an extensive milling process that could benefit from a reliable source of electric power, said Leinart. "If you lose power for a grinder filled with 20 tons of crushed rock, it is extremely difficult to get started again," she said. "The need for reliable power is huge."

Even mines connected to the electric grid might benefit from the process-heat and electricity provided by microreactors and other advanced reactors.

In Nevada, operators of one gold mine have opted to supply their own power through coal, gas, and solar due to unreliable electricity from the grid.

"You're basically operating 24 hours a day, and there's a steady demand for electricity and heat," said Kaitlyn Bullock, a former employee who was tasked with seeking carbon-free energy sources for the mine. "It was connected to the grid, but there were power fluctuations. If California wanted power, you had to start curtailing your operations."

"I looked at solar and wind plus battery storage, as well as geothermal," said Bullock, who is now earning her master's degree in nuclear engineering from KTH Royal Institute of Technology in Sweden. "The most recent technology I looked at was nuclear. In my mind, that was really the energy source that best met the need in that region."

Further, because microreactors are small and capable of being transported, they could provide a good portable power source for an industry where market fluctuations sometimes cause mining operations to close and relocate.

Likewise, if a mine extends operation, a microreactor could be swapped out for a freshly fueled unit capable of operating for another five to 20 years.

Incentives and markets

The interest in using microreactors to power mining operations coincides with the passage of federal laws, including the Inflation Reduction Act of 2022, that could incentivize a company's contribution to a clean energy future.

"Some of these new laws provide tax credits for industries that produce critical minerals for solar cells, batteries and wind turbines," said Shropshire. "These credits could particularly benefit projects in communities with closed coal mines or retired coal-fired power plants."

If microreactors are coupled with these industries, these credits could make their products less expensive, which, in turn, could help microreactors deploy faster.

International markets that incentivize carbon-free imports like green steel could provide an important source of revenue for U.S. companies that use microreactors.

"We're exploring how the inclusion of low-carbon nuclear can support production of green products that increase our competitiveness on the international scale," Shropshire said.