|Fig. 1: One potential design for a Small Modular Reactor. (Courtesy of the DOE)|
Small nuclear reactors are typically defined as reactors with less than 300 megawatts of capacity, compared to the 1,000-plus megawatt capacities of large nuclear facilities.  These reactors are commonly known as small modular reactors (SMRs). Because of their small size, most SMRs are usually assembled in offsite factories and then transported to their final destination.  As power demand increases, additional SMRs can readily be installed, making SMR-facilities highly scalable. These reactors can operate independently of established electrical grids, allowing them to survive through blackouts and act as secondary back-up power sources.  Fig. 1 shows one potential design of these reactors and provides a high-level explanation of how they work. Given their potential strengths, SMRs have become highly attractive to one of the worlds largest energy users: the United States military. Specifically, the US military is investigating using SMRs to provide power to military bases, both domestic and abroad.  This report will discuss the potential benefits and risks associated with using SMRs in these two environments.
To power domestic military bases, the US military currently relies on civilian power grids. In fact, US military installations receive 99% of their power from the civilian power grid.  This grid is decades old and suffers from reliability concerns. The fragility of this grid was clearly demonstrated in the 2003 Northeast blackout, which resulted in more than 50 million people in the US and Canada losing power for up to a week. Additionally, recent reports from the Department of Homeland Security suggest that a coordinated attack on the US power grid could result in a third of the country losing power, including military bases in the affected areas.  While these installations have backup power sources, in the form of gas-powered generators, these solutions can only last for a few days at most. Given these risks, the US military has repeatedly stated its desire to transform military bases into islands of energy self-sufficiency. Doing so would allow them to survive grid-wide blackouts, ensuring their operational resiliency and ability to distribute aid in these scenarios. 
Because of their relatively light individual power demands, US military installations could likely be powered by a single SMR, giving them complete independence from the civilian power grid.  Additionally, if a single SMR is not sufficient, the scalability of SMRs allows for tailored solutions to be created for each individual installation, as required. Last, the use of SMRs, which produce energy with little environmental impact, would help the US Military reduce its carbon footprint, in line with its stated goals to reduce greenhouse gas emissions. 
Many of the benefits SMRs offer to domestic bases energy independence, scalability, reduced emissions also apply to forward operating bases. Importantly, the transportability of SMRs is the key factor making the installation of nuclear reactors in abroad military installations possible. Already constructed reactors can be shipped to their final destinations and installed with much greater ease than constructing a reactor end-to- end on site.  SMRs present a much more attractive alternative to the militarys existing methods of powering their forward operating bases: gas-powered fuel generators.  To resupply these generators, the military utilizes a fleet of fuel trucks. Because of their recognized importance, these trucks represent high-value targets to enemies surrounding these forward operating bases; between 2002 and 2011, approximately 1,000 soldiers were killed on fuel-related missions.  Shifting power generation to SMRs would drastically reduce or possibly even eliminate - the need for these dangerous resupply missions, potentially saving lives in the process.
Despite their many strengths, the use of SMRs is not without drawbacks. Adding additional nuclear reactors, which would likely be spread across the country and possibly even the globe, significantly increases the difficulty of managing nuclear waste disposal. In the case of SMRs on domestic installations, the waste would likely need to be transported long distances to existing nuclear waste storage facilities.  In the case of forward operating bases, this issue becomes even more complex with no easy existing solution.
One cannot advocate for the increased use of nuclear reactors without addressing the issue of potential attack on these sites. While SMRs on domestic military installations would undoubtedly be potential targets of terrorist attacks, they are just as secure as large-scale facilities while also being capable of only a fraction of the devastation.  The real issue concerns the security of SMRs on forward operating bases. Many US forward operating bases are located in, or near, countries that are home to hostile insurgent groups. As a result, these installations are frequently subject to mortar attacks, making any SMR located on a forward operating base an extremely at-risk and high-value target. Even more pressing, these bases are at risk of being captured by the enemy.  In this case, the deployment of SMRs to forward operating bases poses a threat to the non-proliferation of nuclear weapons.
Ultimately, SMRs provide substantial benefits to both domestic and abroad military installations. However, the risks associated with storing fissile material in hostile environments significantly outweigh any potential benefits an SMR may offer.  Consequently, SMRs are a strong solution for powering domestic military bases, but are not feasible for use on forward operating bases. In line with these conclusions, the Department of Defense has called for at least one SMR to be installed on a domestic military base by 2027, but has no immediate plan for SMRs on any forward operating base.  This SMR will serve as an experiment to gauge the value of adding further SMRs to other bases. For this pilot program, the Department of Defense is looking at SMRs from several companies: General Atomics, NuScale, Oklo, Westinghouse, and X-Energy. 
© Thomas Rogers. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
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