Defense Department Sets Out to Build Miniature Nuclear Reactor, Again

Small, deployable nuclear reactors, an idea that the United States military has been experimenting with for decades, will receive new life under a program the Defense Department announced Thursday. 

And unlike previous efforts to deploy alternatives to diesel and other fossil-fuel generators, which were stalled by high costs and little political support, this new effort may succeed in helping the military, and eventually commercial energy providers, wean themselves off carbon-intensive power. As one expert explained, while the physics haven’t changed,  increasing concerns about the geopolitics of fossil fuels coupled with growing concerns about climate change have made the effort more critical. 

Under the new program, the Defense Department will build a 1-5 MegaWatts nuclear microreactor at Idaho National Laboratory for a three-year (minimum) test operational period. It will be “the first electricity-generating Generation IV nuclear reactor built in the United States,” the Defense Department said in a statement. “The first electricity-generating Generation IV nuclear reactor demonstrated in the world was the HTR-PM, a Chinese reactor, which first reached criticality in September 2021.”

The announcement makes clear that it’s not only competition with China that’s pushing a reconsideration, but also growing attention to the Defense Department’s massive carbon footprint. 

“The DOD uses approximately 30 terawatt-hours of electricity per year and more than 10 million gallons of fuel per day—levels that are only expected to increase due to anticipated electrification of the non-tactical vehicle fleet and maturation of future energy-intensive capabilities,” it reads. “A safe, small, transportable nuclear reactor would address this growing demand with a resilient, carbon-free energy source that would not add to the DOD’s fuel needs, while supporting mission-critical operations in remote and austere environments.”

Project Pele, as it’s called, won’t be the first microreactor the U.S. military has produced. In 1954, the joint chiefs of staff launched a program to look at military use of nuclear power. That effort produced three reactors: one that powered an air and missile defense radar station near Sundance, Wyoming, one for Greenland, and another that powered the McMurdo Station in Antarctica for a decade. 

In 1963, the effort produced a reactor that could fit on a large truck bed, the ML-1. But the costs were deemed too high at the time, compared to diesel generators, so the program died in 1977. 

A few decades later, in the early 2000s, the U.S. military looked at the concept again as a means to power remote bases in places like Afghanistan and Iraq, alarmed by the number of troops killed while trying to deliver and retrieve diesel fuel in those environments. DARPA launched a new program in 2011 to consider the costs and benefits of mobile nuclear reactors for remote forward operating bases. 

The idea, it turned out, didn’t work well for the types of bases the  United States inhabited in Afghanistan and Iraq. As University of Texas professor Alan J. Kuperman argued in an April 2021 paper, “Significant doubt remains about the need, advisability, and plausibility of this initiative. The original rationale—to reduce U.S. casualties from attacks on shipments of diesel fuel for electricity generation on foreign military bases—is a vestige because such casualties have dwindled virtually to zero.” 

There are safety concerns as well. Mobile nuclear reactors today shouldn’t be compared to Chernobyl or other big nuclear disasters from decades past. But, in a battlefield context, they could still be dangerous. As Kuperman argued, a missile targeting a mobile microreactor could result in radioactive material getting out. And the reactor can’t be buried, because it needs passive cooling in the event of a temperature buildup. 

But the idea has taken on new relevance and is finding renewed support, said Paul Roege, a retired Army colonel who managed a $150 million program for DARPA examining the concept.

There’s a new appreciation in the United States government that small nuclear reactors could help the United States maintain a long-term presence in the Asia- Pacific region, where the military must operate in much greater numbers to deter China from launching an invasion of Taiwan. 

“It's quite public that the United States is building some radar systems in Palau. You would need to have some amount of energy, but you know, not tens of megawatts, maybe a few megawatts to one radar systems to run radios, to run the internet,” he said.

The United States is looking to establish a presence in the Asia-Pacific region, and plans to maintain that presence for much longer than the military was in Afghanistan or Iraq. And the longer a nuclear plant is expected to be in operation, the more economically attractive nuclear power becomes, he said.  Additionally, if the U.S. military could bring an energy surplus with them, that could help local governments insulate themselves economically from Chinese influence, he said. 

And, while nuclear power is not a good choice to power a tank, it could be used to run servers or other technology as the military moves toward information-heavy future operations, he said. 

But perhaps the biggest reason Roege believes the concept could have widespread appeal is the significant shift among governments in their willingness to consider new nuclear power, particularly as leaders see how . autocratic states like Russia can energy as a coercion tool. 

“Romania has quite a bit of nuclear power. The Czech Republic and a couple others have become quite interested over the last few years because, you know, they want an alternative [to Russian oil and gas],” he said. Those countries are concerned about climate change, “and they're also not convinced that they want to be under the thumb of Russia as an energy source. Last year, a number of the EU countries’ leaders wrote to the leadership of the EU and said ‘We want nuclear to be considered one of the clean energy options.’” 

The politics around nuclear power have also changed in the United States and among U.S. leadership. He recalled opposition he encountered during the Obama Administration to the idea. Republican officials during the Trump Administration were more receptive. Among Biden Administration officials, he says that there’s even more interest as the administration looks at ambitious carbon reduction goals particularly for the United States military.