The United States Army officially announced last week that nuclear microreactors are coming to American military bases. Roughly $2.2 billion will be distributed among five companies through the Janus program.
The initiative calls for the development of 20 prototypes that will be owned and operated by contractors at five bases. The first reactor is expected to be operational by the fall of 2028.
The program is driven by two strategic vulnerabilities identified by U.S. officials: the possibility that the domestic power grid could be attacked during a conflict and the difficulty of transporting fossil fuels to locations where they are needed.
“Unlike in prior conflicts, we now know that our domestic electric grid is potentially at risk in a conflict. We also know that we will not necessarily be able to move fossil fuels easily wherever we need them to go,” said Jeff Waksman, the Army’s principal deputy assistant secretary for installations, energy and environment.
Waksman acknowledged that developing the reactors will be extremely difficult and that there is a real possibility that one or more of the companies involved in the program could fail.
Question 1: How will nuclear waste be handled?
The microreactors selected for the Janus program are at different stages of development. Their operating cores could have service lives ranging from only a few years to as long as two decades.
Some designs call for above-ground reactors, while others would require excavation. That creates a central challenge: determining how radioactive waste will be handled and how possible soil contamination will be prevented.
Waksman said protecting the surrounding soil would be a major contractual requirement. All radioactive material would have to be removed from the site within two years after operations end.
The Army does not intend to leave contaminated soil behind or maintain long-term nuclear waste storage at the bases hosting the reactors.
The precise procedures, however, have not yet been finalized. The Army is discussing an arrangement with the Department of Energy under which the waste would be transported to a DOE facility. In exchange for accepting the material, the department would receive funding and assume legal responsibility for the waste.
The Army does not plan to establish its own nuclear waste facility, viewing such a solution as impractical and unnecessary.
Question 2: Will there be enough fuel for all 20 reactors?
All five companies selected for Janus are using High-Assay Low-Enriched Uranium, or HALEU. The fuel contains uranium-235 enriched to between 5% and below 20% and is used to produce TRISO fuel particles for the reactor cores.
The United States currently does not have enough HALEU to supply all 20 microreactors planned under the program.
Existing supplies are expected to be prioritized for the fastest-moving reactor designs. However, supporting more than 20 reactors could exceed the nation’s current supply capacity.
The Army is not the only government institution competing for HALEU. NASA plans to use the fuel for its SR-1 mission, while other government projects are also in development.
The administration is therefore seeking to expand the country’s uranium-enrichment capacity. The Department of Energy is examining the possibility of producing HALEU by downblending highly enriched uranium.
Current plans include $2.7 billion in spending over the next decade to expand domestic enrichment services for both low-enriched uranium and HALEU.
The Janus program will consequently depend on a broader government effort combining existing stockpiles with new production and enrichment capabilities.
Question 3: Can the Pentagon afford to expand the program?
The $2.2 billion allocated to Janus is primarily intended to develop and bring the prototypes online. The actual installation of microreactors at military bases will require significantly more funding.
Expanding the program to additional bases across the United States, and eventually to overseas facilities, could drive costs much higher.
Some companies have offered estimates for the future price of their reactors, but the Army does not yet know whether the contractor-owned and contractor-operated model will prove financially viable.
Microreactors are not expected to produce electricity at the same cost as large nuclear reactors. Their smaller size creates engineering and physics-related limitations, although those costs may be acceptable in remote or difficult-to-supply locations.
In austere areas, the Army regularly pays approximately 40 cents per kilowatt-hour for natural gas-generated electricity. If microreactor power were to cost $1 per kilowatt-hour, the model would not be viable.
One of the selection criteria was confidence that the participating companies could reduce their costs to a level useful for Army operations.
Question 4: How will the reactors be protected?
A nuclear reactor located on a military base could become an attractive target for state and non-state adversaries.
Although a conventional attack against a facility on U.S. soil may appear unlikely, physical sabotage or cyberattacks could be used to disrupt operations and trigger a serious emergency.
The Janus microreactors will not use highly enriched uranium, defined as uranium enriched above 20%. As a result, they will not require the same safeguards used for nuclear weapons or naval reactors.
Their location on Army installations will nevertheless allow the service to rely on existing military security infrastructure. The program requires physical protection for the reactors as well as additional safeguards for critical infrastructure beyond what is normally found in the private sector.
Specific security measures have not been disclosed. Protection is expected to address both physical attacks and cyber threats.
The U.S. military already uses air defense and counter-drone systems to protect critical infrastructure. At the same time, the administration is laying the groundwork for Golden Dome, a multilayered national air and missile defense architecture.
Question 5: Who will regulate the reactors?
Microreactors installed at Army bases will be licensed by the military rather than by the U.S. Nuclear Regulatory Commission.
The program is also intended to help companies develop reactors that could eventually be sold commercially. For that reason, the Army is working with the NRC to make the civilian licensing process as smooth as possible.
There is currently no formal joint licensing procedure. A reactor licensed by the Department of Energy would not automatically be licensed by the Army, and an Army-approved reactor would not automatically be approved by the NRC.
The Army wants to prevent a situation in which a company designs a reactor according to military requirements and later discovers that civilian regulators impose entirely different standards for software, materials or other critical components.
Environmental laws will also apply. The reactors will have to comply with the same rules that govern commercial nuclear facilities, including the Clean Air Act and the National Environmental Policy Act.
Recent reforms could speed up environmental reviews, but they will not eliminate the legal obligations. Military microreactors will still have to meet all relevant environmental protection and nuclear safety requirements.
