ENERGY RESILIENCE THROUGH MICROREACTORS
Compact reactors could power remote bases for decades. A pilot in the Arctic may prove nuclear’s next chapter to be small, safe, and portable.
Written by Nicole Imeson
IN THE ICY LANDSCAPES OF ALASKA, a new kind of nuclear reactor is being built to keep the lights—and the heat—on.
The Department of the Air Force (DAF) and the Defense Logistics Agency Energy Office launched a pilot project to develop and operate a nuclear microreactor at the Eielson Air Force Base in Fairbanks, Alaska. The new class of nuclear reactors promises to deliver reliable, off-grid power to some of the world’s harshest environments.
For the Air Force, reliable power in the Arctic isn’t just about comfort. “Eielson Air Force Base in Alaska is the preferred location for the pilot due to the existing infrastructure, Arctic conditions, geostrategic location, critical mission resilience needs, and national security importance,” explained Laurel Falls, Current Operations Division, DAF Public Affairs.
The first-of-its-kind military effort aims to test advanced nuclear power to improve energy resilience in an environment where temperatures can plunge below -40 °F and daylight disappears for weeks. The microreactor would deliver 5 megawatts of electricity and supplement thermal energy to critical base infrastructure.
Aircraft assigned to the 354th Fighter Wing and 168th Wing line the runway at Eielson Air Force Base in Alaska. Eielson will pilot the Air Force’s first microreactor due to the installation's existing infrastructure, suitable climate, and critical mission resilience requirement. Photo: Senior Airman Keith Holcomb/U.S. Air Force
Small reactors, big potential
Microreactors use nuclear fission to produce heat and convert it into electricity. When a neutron strikes a fissile material such as uranium-235, the atom splits, releasing heat and more neutrons. These new neutrons trigger additional fissions, sustaining the reaction and continuously generating energy.
Traditional thermal-neutron reactors rely on light water moderators to slow down neutrons and sustain fission. In contrast, fast-neutron microreactors sustain the chain reaction using high-energy neutrons and dense metal alloy fuels, including recycled spent nuclear waste from larger reactors. These dense fuels pack more fissile uranium-235 into a smaller core, enabling longer run times, with some microreactors operating for 10 to 20 years without refueling.
Fast-neutron reactors, like the microreactor intended for Eielson Air Force Base, transfer fission heat to a primary coolant, often liquid sodium, which carries energy through a heat exchanger. There, a secondary coolant absorbs the heat and produces steam, which turns a turbine and generates electricity.
Oklo Inc. was recently issued a Notice of Intent to Award to design, construct, own, and operate a microreactor as part of a nuclear energy pilot at Eielson Air Force Base. This artist’s concept image will be similar to a facility that will provide reliable, and secure power. Image: Oklo Inc.
An F-35A Lightning II assigned to the 355th Fighter Squadron takes off from Eielson Air Force Base in Alaska on July 1, 2021. Photo: Airman 1st Class Jose Miguel T. Tamondong/U.S. Air Force
Power and heat from the same core
Every puff of steam serves a dual purpose: first turning turbines, then warming buildings. At sites that only require electricity, operators condense the steam back into water after it passes through the turbine, then recycle it through the microreactor. But in Arctic climates like Eielson Air Force Base, engineers will give the steam a second job, heating buildings. After generating power, the steam flows through a second heat exchanger, where it produces hot water that circulates throughout the facility.
Microreactors’ compact size, passive safety, and long refueling cycles enable efficient combined heat and power (CHP) systems, or cogeneration plants on a smaller scale, without relying on fossil fuels. Engineers deploy them in remote or space-constrained environments that traditional cogeneration systems could not serve.
As zero-carbon energy sources, microreactors could open new pathways to decarbonize heat and power generation. They may help facilities reduce emissions, cut operational risk, and strengthen energy independence, all from a single, small-footprint reactor.
“The DAF strives to stay on the forefront of energy innovation and seeks state-of-the-art technologies that increase energy resilience and reliability to reduce the potential loss of critical mission capabilities due to power disruptions,” Falls explained.
Eielson Air Force Base will soon be home to a microreactor as well. The base’s welcome sign stands alongside the Richardson Highway. Established in 1943 as Mile 26 Satellite Field, the site was later redesignated as Eielson Air Force Base on Jan. 13, 1948. Photo: Airman 1st Class Carson Jeney/U.S. Air Force
Built small, built safe
Engineers are designing microreactors at a fraction of the size of conventional reactors, producing between 1 and 50 megawatts compared to more than 1,000 megawatts from full-scale plants. Manufacturers aim to assemble them in factories and transport completed units by truck, rail, or ship, eliminating the need for large on-site construction. This modular approach enabled operators to run multiple reactors in parallel where required to meet larger energy demands.
Designers prioritize passive safety, building systems that self-regulate and shut down during abnormal conditions such as coolant loss. Rising temperatures expand the reactor core, increase the distance between fissile atoms, reduce collisions, slow the chain reaction, and halt heat generation—all without external power or human intervention.
In cases of pump failure, liquid metal coolant would circulate through natural convection. As it absorbs heat, the less dense, warmer coolant would rise while the cooler, denser fluid would sink, creating a continuous flow that removes heat from the core without mechanical support.
“Microreactors are designed with automatic safety features. This significantly reduces the potential for accidents and risk to the installation or surrounding communities,” Falls said.
Contracting for a nuclear future
In June 2025, the DAF and the Defense Logistics Agency Energy Office issued a Notice of Intent to Award (NOITA) to Oklo Inc. The deal is essentially a 30-year bet that compact nuclear power can thrive in the Arctic—the proposed agreement requires Oklo to license, build, operate, maintain, and decommission a microreactor at Eielson Air Force Base. In exchange, the DAF would commit to a long-term purchase of the electricity and steam it generates.
“The DAF Microreactor Pilot will inform best practices and lessons learned for future scaling of advanced nuclear energy technology,” Falls explained. “The DAF is also working with the Defense Innovation Unit (DIU) on Advanced Nuclear Power for Installations (ANPI), a DIU-led initiative which seeks to deploy advanced nuclear power to Department of Defense installations.”
Next steps for the pilot project include conducting a full environmental analysis to assess site suitability and confirm the proposed microreactor location. Subsequently, they will seek licensure and design approval from the U.S. Nuclear Reactor Commission (NRC), along with authorization from the DoD Deputy Assistant Secretary of Defense for Energy Resilience and Optimization.
If successful, the Eielson pilot could mark the start of a new nuclear era—one where power plants are portable, resilient, and as common as wind farms. The DAF’s interest in advanced nuclear solutions reflects a strategic move toward scalable, resilient energy across defense operations and beyond.
Nicole Imeson is an engineer and writer in Calgary, Alberta.
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