The U.S. Military Wants Tiny Road Mobile Nuclear Reactors That Can Fit In A C-17

The U.S. military’s secretive Strategic Capabilities Office, or SCO, is asking for potential vendors to submit proposals for small mobile nuclear reactors to help meet ever-growing demands for power during operations in remote and austere locations. This request for information comes as the U.S. Army, in particular, is looking to extend the amount of time its units can operate independent of established supply chains, but portable nuclear power could introduce new risks to the battlefield.

SCO first announced that they were looking for “information on innovative technologies and approaches” relating to a possible future “small mobile nuclear reactor prototype design” on FedBizOpps, the U.S. government’s main contracting website, on Jan. 18, 2019. The organization posted an amended version of the notice, which outlines a “multi-phase prototype project” as part of what it is calling Project Dilithium, four days later.

“Energy usage during contingency operations will likely increase significantly over the next few decades,” the latest version of the request for information explains. “The modern operational space has amplified the need for alternative energy sources to enable mobility in forward land based and maritime military operations.”

SCO basic requirements envision a reactor that can generate between one and 10 megawatts of energy, less than the average output for even a small research reactor, and weigh less than 40 tons. The final design would need to be portable by semi-trailer truck, ship, or a U.S. Air Force C-17A Globemaster III cargo plane.

A diagram from a previous US military report depicting a potential concept of operations for deploying a mobile nuclear reactor., DOD

The goal is to develop a system that personnel can set up in three days or less and shut down and pack up in less than a week. The reactor itself would remain functional for at least three years without needing new fuel.

SCO is hoping to consider up to three designs under the first phase of the project, which would be an in-depth design study that would last between nine and 12 months. The plan is to then down select to a single design for Phase II, in which the winning contractor would build and demonstrate their prototype reactor.

There are a number of potential concepts already in various stages of development that could meet SCO’s requirements. The U.S. Department of Energy’s own Los Alamos National Laboratory (LANL), in cooperation with the Westinghouse power company, has been working on one design called MegaPower for some time now. Westinghouse is separately working on its own eVinci micro reactor design.

The MegaPower reactor can generate at least one megawatt of power for up to 10 years and meets the SCO’s demands for how long it takes to set up and tear down. More importantly, the design uses what are known as “heat pipes” to both keep the system cool and generate power, eliminating the need for complex and potentially hazardous water-cooling arrangements. The video below describes how this arrangement works in more detail.

Another option in development is Filippone and Associates LLC’s Holos, a unique gas-cooled modular reactor. Named after the Greek word meaning “whole,” the design only “goes critical” and works as intended when a certain number of modules are positioned together, touching off the nuclear reaction. Each self-contained modular has its own turbine generator that then produces power.

A standard four-module arrangement is small enough to fit inside a standard ISO shipping container. Depending on the exact configuration, Filippone and Associates says Holos can generate between three and 13 megawatts and has an operational life of up to 60 years. You can learn more about this design in the video below.

There are other small nuclear reactors either available or in development, such as the URENCO U-Battery and StarCore’s micro reactor, but these are not necessarily intended to be rapidly repositioned from one place to another. They could require significant modifications to meet the portability requirements that SCO is looking for.

There is no fixed timeline yet for when Phase I might begin, but as the request for information notes, there is already significant demand for this kind of miniaturized portable power plant. Electrical power demands are only likely to increase in the near future as the U.S. military continues to expand its use of communications and networking capabilities, mobile sensor and electronic warfare systems, and more. Living spaces, mess halls, and other more general facilities all need electricity, too. Electric or hybrid electric vehicles and electrically-powered weapons, such as railguns and directed energy weapons, will only add to these power generation requirements.

At present, deployed U.S. military forces rely almost entirely on established power grids and their own fossil-fuel powered generators to generate the required power to keep bases and forward operating sites up and running. Especially at remote and austere locations, this requires a steady supply of diesel or other fuels either by ground convoy or aircraft.

This can quickly become a costly proposition and demands additional resources to safeguard those supply lines. Any disruption can severely degrade deployed units’ combat effectiveness and put them at risk of losing communications and situational awareness if the power goes out or has to be rationed. You can read more about these issues in detail here.

These are the kind of concerns that led the U.S. Army to announce in November 2018 that it was looking for ways to ensure its brigade combat teams would be able to fight for a week without getting resupplied. This is twice as long as those units can operate without fuel and other supplies at present.

The Army is certainly watching the SCO’s Project Dilithium, if it isn’t involved in it directly. In October 2018, the service put out its own report on the potential uses of nuclear power on the battlefield.

“This study finds that as a technical matter, nuclear power can reduce supply vulnerabilities and operating costs while providing a sustainable option for reducing petroleum demand,” that report concluded. “Energy is a cross-cutting enabler of military power and nuclear fuel provides the densest form of energy able to generate the electrical power necessary at forward and remote locations without the need for continuous fuel resupply.”

The other branches of the U.S. military have their own requirements for this kind of portable power, as well. The Air Force and the Marine Corps are both actively exploring new concepts for rapidly establishing bases that could benefit from the addition of power from small nuclear reactors.

But this is hardly the first time the U.S. military has explored using mobile nuclear reactors to meet its power needs. The Army experimented with a host of land-based designs between the 1950s and 1970s, before shelving the concept. The service was responsible for building the world’s first-ever land-transportable, mobile nuclear power plant, the ML-1.

A US Army truck tows the ML-1 reactor during a test., US Army

The SCO’s Project Dilithium itself looks to be the latest evolution of a more recent effort that has been going on for more than a decade now. That led to Defense Advanced Research Projects Agency (DARPA) receiving funding to explore “Small Rugged Reactor Technologies” in the defense budget for the 2012 Fiscal Year and the development of LANL’s MegaPower design. In 2016, the Defense Science Board further promoted the development of mobile nuclear power in another report about power options for forward and remote bases.

However, one of the biggest potential problems with battlefield nuclear power continues to be safety. There are obvious concerns about what happens when you begin deploying dozens, if not hundreds of small nuclear reactors into areas that are, by definition, full of hostile threats.

The SCO’s requirements demand a design that is incapable of melting down, does not require constant monitoring for otherwise safe operation, and doesn’t present an immediate health hazard. LANL and Filippone and Associates LLC both claim that their designs meet these requirements through inherent safety features in their respective designs.

But even if the reactor itself cannot catastrophically fail, something that may be a tall order to ensure in austere conditions regardless of the design, powering remote and austere bases with nuclear power could run other risks. If hostile forces end up destroying the reactor, it could potentially lead to the hazardous dispersal of radioactive material.

Members of Alaska Army National Guard’s 103rd Civil Support Team conduct a mock radiological reconnaissance mission during an exercise in 2018., US Army

This, in turn, could produce short- and long-term health and safety concerns for U.S. forces and innocent civilians in the surrounding area. Even if the risk is minor, the perception of those dangers could impact public opinion about American military activities and give an opponent ample opportunity to spread harmful misinformation and disinformation. A good example of how this might play out is the mix of reasonable public concerns and Russian propaganda over U.S. military-sponsored disease prevention and biological warfare defense programs.

There’s also a proliferation issue in building a large number of mobile reactors and placing them in war zones. There is also a matter of disposing of the nuclear waste material they’ll produce. The U.S. government, as well as its allies and partners around the world, expend considerable effort ensuring that radioactive material of any kind is safeguarded.

A reactor that is by design mobile would almost certainly be an attractive target for terrorists or militants looking to build a so-called “dirty bomb” that mixes radiological material and conventional explosives. Experts continue to debate the actual threat that these devices actually pose, but there seems to be little doubt that they could be particularly capable of creating widespread panic.

Radioisotope thermoelectric generators on board a US Air Force C-17 in preparation for their movement to the Nevada National Security Site for disposal in 2015., USAF

On top of that, unlike existing portable generators, any mobile nuclear reactor would require much more robust control systems to ensure its safe and reliable operation. Depending on the reactor’s exact configuration, there is the possibility that a cyber attack might be able to shut it down or otherwise hamper its operation at a critical point.

In October 2018, the Government Accountability Office released a report that slammed the Department of Defense’s existing protections against cyber attacks and said that the U.S. military did not have a good grasp of the extent of the potential threat. Nuclear reactors spread across an area of operations would only increase the potential vectors for such an attack.

“The Task Force sees the need and benefit outweighing the difficulty in achieving nearly limitless energy on the battlefield,” the Defense Science Board concluded in 2016. “The Task Force did not find the technology to be unachievable nor are the deployment issues impossible; the U.S. military has overcome comparable challenges before.”

Other alternatives may become more practical as time goes on, as well. including miniaturized fusion reactors and hydrogen fuel cell technology. It seems likely that the U.S. military will eventually pursue a mix of different power generation options rather than any one single technology.

Still, the increasing demand for battlefield power is certainly a very real issue and portable nuclear reactors could provide a solution, or at least part of a solution, to that problem. It now looks to be up to SCO’s Project Dilithium to determine whether or not the available technology has finally reached a point where it is actually safe and practical for widespread military use.

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