Nuclear Power:  An Option for the Army's Future

by Robert A. Pfeffer and William A. Macon, Jr.

    The Army Transformation initiative of Chief of Staff General Eric K. Shinseki represents a significant change in how the Army will be structured and conduct operations. Post-Cold War threats have forced Army leaders to think "outside the box" and develop the next-generation Objective Force, a lighter and more mobile fighting army that relies heavily on technology and joint-force support. More changes can be anticipated. As we consider what the Army might look like beyond the Objective Force of 2010, nuclear power could play a major role in another significant change: the shift of military energy use away from carbon-based resources. Nuclear reactor technology could be used to generate the ultimate fuels for both vehicles and people: environmentally neutral hydrogen for equipment fuel and potable water for human consumption.

Evolving Energy Sources

    Over the centuries, energy sources have been moving away from carbon and toward pure hydrogen. Wood (which has about 10 carbon atoms for every hydrogen atom) remained the primary source of energy until the 1800s, when it was replaced with coal (which has 1 or 2 carbon atoms for every hydrogen atom). In less than 100 years, oil (with two hydrogen atoms for every carbon atom) began to replace coal. Within this first decade of the new millennium, natural gas (with four hydrogen atoms for every carbon atom) could very well challenge oil's dominance.

    In each case, the natural progression has been from solid, carbon-dominated, dirty fuels to more efficient, cleaner-burning hydrogen fuels. Work already is underway to make natural gas fuel cells the next breakthrough in portable power. However, fuel cells are not the final step in the evolution of energy sources, because even natural gas has a finite supply. Fuel cells are merely another step toward the ultimate energy source, seawater, and the ultimate fuel derived from it, pure hydrogen (H2).

Environmental Realities

    There are three geopolitical energy facts that increasingly are affecting the long-term plans of most industrialized nations—

           Worldwide coal reserves are decreasing. At the present rate of consumption, geological evidence indicates that worldwide low-sulfur coal reserves could be depleted in 20 to 40 years. This rate of depletion could accelerate significantly as China, India, and other Third World countries industrialize and use more coal.

            Most major oil reserves have been discovered and are controlled by just a few OPEC [Organization of Petroleum-Exporting Countries] nations. Some of these reserves are now at risk; Bahrain, for example, estimates that its oil reserves will be depleted in 10 to 13 years at the current rate of use.

            The burning of carbon-based fuels continues to add significant pollutants to the atmosphere.

    These and other socioeconomic pressures are forcing nations to compete for finite energy sources for both fixed-facility and vehicle use. For the United States, the demand for large amounts of cheap fuel to generate electricity for industry and fluid fuel to run vehicles is putting considerable pressure on energy experts to look for ways to exploit alternate energy sources. The energy crisis in California could be the harbinger of things to come. The threat to affordable commercial power could accelerate development of alternative fuels. It is here that private industry may realize that the military's experience with small nuclear power plants could offer an affordable path to converting seawater into fuel.

Military Realities

    Today, the military faces several post-Cold War realities. First, the threat has changed. Second, regional conflicts are more probable than all-out war. Third, the United States will participate in joint and coalition operations that could take our forces anywhere in the world for undetermined periods of time. Finally, the U.S. military must operate with a smaller budget and force structure. These realities already are forcing substantial changes on the Army.

    So, as we consider future Army energy sources, we foresee a more mobile Army that must deploy rapidly and sustain itself indefinitely anywhere in the world as part of a coalition force. In addition, this future Army will have to depend on other nations to provide at least some critical logistics support. An example of such a cooperative effort was Operation Desert Storm, where coalition forces (including the United States) relied on some countries to supply potable water and other countries to provide fuel. This arrangement allowed U.S. cargo ships to concentrate on delivering weapon systems and ammunition.

    But consider the following scenario. The U.S. military is called on to suppress armed conflict in a far-off region. The coalition forces consist of the United States and several Third World countries in the region that have a vested interest in the outcome of the conflict. Our other allies are either unwilling or unable to support the regional action, either financially or militarily. The military effort will be a challenge to support over time, especially with such basic supplies as fuel and water. How can the United States sustain its forces?

    One way to minimize the logistics challenge is for the Army to produce fuel and potable water in, or close to, the theater. Small nuclear power plants could convert seawater into hydrogen fuel and potable water where needed, with less impact on the environment than caused by the current production, transportation, and use of carbon-based fuels.

Seawater: The Ultimate Energy Source

    Industrial nations are seeing severe energy crises occur more frequently worldwide, and, as world population increases and continues to demand a higher standard of living, carbon-based fuels will be depleted even more rapidly. Alternative energy sources must be developed. Ideally, these sources should be readily available worldwide with minimum processing and be nonpolluting. Current options include wind, solar, hydroelectric, and nuclear energy, but by themselves they cannot satisfy the energy demands of both large, industrial facilities and small, mobile equipment. While each alternative energy source is useful, none provides the complete range of options currently offered by oil. It is here that thinking "outside the box" is needed.

    As difficult as the problem seems, there is one energy source that is essentially infinite, is readily available worldwide, and produces no carbon byproducts. The source of that energy is seawater, and the method by which seawater is converted to a more direct fuel for use by commercial and military equipment is simple. The same conversion process generates potable water.

Seawater Conversion Process

    Temperatures greater than 1,000 degrees Celsius, as found in the cores of nuclear reactors, combined with a thermochemical water-splitting process, is probably the most efficient means of breaking down water into its component parts: molecular hydrogen and oxygen. The minerals and salts in seawater would have to be removed by a desalination process before the water-splitting process and then burned or returned to the sea.

    Sodium iodide (NaI) and other compounds are being investigated as possible catalysts for high-temperature chemical reactions with water to release the hydrogen, which then can be contained and used as fuel. When burned, hydrogen combines with oxygen and produces only water and energy; no atmospheric pollutants are created using this cycle.

    Burning coal or oil to generate electricity for production of hydrogen by electrolysis would be wasteful and counterproductive. Nuclear power plants, on the other hand, can provide safe, efficient, and clean power for converting large quantities of seawater into usable hydrogen fuel.

    For the military, a small nuclear power plant could fit on a barge and be deployed to a remote theater, where it could produce both hydrogen fuel and potable water for use by U.S. and coalition forces in time of conflict. In peacetime, these same portable plants could be deployed for humanitarian or disaster relief operations to generate electricity and to produce hydrogen fuel and potable water as necessary. Such dual usage (hydrogen fuel for equipment and potable water for human consumption) could help peacekeepers maintain a fragile peace. These dual roles make nuclear-generated products equally attractive to both industry and the military, and that could foster joint programs to develop modern nuclear power sources for use in the 21st century.

So What's Next?

    The Army must plan for the time when carbon-based fuels are no longer the fuel of choice for military vehicles. In just a few years, oil and natural gas prices have increased by 30 to 50 percent, and, for the first time in years, the United States last year authorized the release of some of its oil reserves for commercial use. As the supply of oil decreases, its value as a resource for the plastics industry also will increase. The decreasing supply and increasing cost of carbon-based fuels eventually will make the hydrogen fuel and nuclear power combination a more attractive alternative.

    One proposed initiative would be for the Army to enter into a joint program with private industry to develop new engines that would use hydrogen fuel. In fact, private industry already is developing prototype automobiles with fuel cells that run on liquefied or compressed hydrogen or methane fuel. BMW has unveiled their hydrogen-powered 750hL sedan at the world's first robotically operated public hydrogen fueling station, located at the Munich, Germany, airport. This prototype vehicle does not have fuel cells; instead, it has a bivalent 5.4-liter, 12-cylinder engine and a 140-liter hydrogen tank and is capable of speeds up to 140 miles per hour and a range of up to 217.5 miles.

    Another proposed initiative would exploit previous Army experience in developing and using small, portable nuclear power plants for the future production of hydrogen and creation of a hydrogen fuel infrastructure. Based on recent advances in small nuclear power plant technology, it would be prudent to consider developing a prototype plant for possible military applications.

The MH-1A Sturgis floating nuclear power plant, a 45-MW pressurized water reactor, was the last nuclear power plant built and operated by the Army.
The MH-1A Sturgis floating nuclear power plant, a 45-MW pressurized water reactor, was the last nuclear power plant built and operated by the Army.

 

The Army Nuclear Power Program

    The military considered the possibility of using nuclear power plants to generate alternate fuels almost 50 years ago and actively supported nuclear energy as a means of reducing logistics requirements for coal, oil, and gasoline. However, political, technical, and military considerations forced the closure of the program before a prototype could be built.

    The Army Corps of Engineers ran a Nuclear Power Program from 1952 until 1979, primarily to supply electric power in remote areas. Stationary nuclear reactors built at Fort Belvoir, Virginia, and Fort Greeley, Alaska, were operated successfully from the late 1950s to the early 1970s. Portable nuclear reactors also were operated at Sundance, Wyoming; Camp Century, Greenland; and McMurdo Sound in Antarctica. These small nuclear power plants provided electricity for remote military facilities and could be operated efficiently for long periods without refueling. The Army also considered using nuclear power plants overseas to provide uninterrupted power and defense support in the event that U.S. installations were cut off from their normal logistics supply lines.

    In November 1963, an Army study submitted to the Department of Defense (DOD) proposed employing a military compact reactor (MCR) as the power source for a nuclear-powered energy depot, which was being considered as a means of producing synthetic fuels in a combat zone for use in military vehicles. MCR studies, which had begun in 1955, grew out of the Transportation Corps' interest in using nuclear energy to power heavy, overland cargo haulers in remote areas. These studies investigated various reactor and vehicle concepts, including a small liquid-metal-cooled reactor, but ultimately the concept proved impractical.

    The energy depot, however, was an attempt to solve the logistics problem of supplying fuel to military vehicles on the battlefield. While nuclear power could not supply energy directly to individual vehicles, the MCR could provide power to manufacture, under field conditions, a synthetic fuel as a substitute for conventional carbon-based fuels. The nuclear power plant would be combined with a fuel production system to turn readily available elements such as hydrogen or nitrogen into fuel, which then could be used as a substitute for gasoline or diesel fuel in cars, trucks, and other vehicles.

    Of the fuels that could be produced from air and water, hydrogen and ammonia offer the best possibilities as substitutes for petroleum. By electrolysis or high- temperature heat, water can be broken down into hydrogen and oxygen and the hydrogen then used in engines or fuel cells. Alternatively, nitrogen can be produced through the liquefaction and fractional distillation of air and then combined with hydrogen to form ammonia as a fuel for internal-combustion engines. Consideration also was given to using nuclear reactors to generate electricity to charge batteries for electric-powered vehicles—a development contingent on the development of suitable battery technology.

    By 1966, the practicality of the energy depot remained in doubt because of questions about the cost-effectiveness of its current and projected technology. The Corps of Engineers concluded that, although feasible, the energy depot would require equipment that probably would not be available during the next decade. As a result, further development of the MCR and the energy depot was suspended until they became economically attractive and technologically possible.

    Other efforts to develop a nuclear power plant small enough for full mobility had been ongoing since 1956, including a gas-cooled reactor combined with a closed- cycle gas-turbine generator that would be transportable on semitrailers, railroad flatcars, or barges. The Atomic Energy Commission (AEC) supported these developments because they would contribute to the technology of both military and small commercial power plants.    

    The AEC ultimately concluded that the probability of achieving the objectives of the Army Nuclear Power Program in a timely manner and at a reasonable cost was not high enough to justify continued funding of its portion of projects to develop small, stationary, and mobile reactors. Cutbacks in military funding for long-range research and development because of the Vietnam War led the AEC to phase out its support of the program in 1966. The costs of developing and producing compact nuclear power plants were simply so high that they could be justified only if the reactor had a unique capability and filled a clearly defined objective backed by DOD. After that, the Army's participation in nuclear power plant research and development efforts steadily declined and eventually stopped altogether.

Nuclear Technology Today

    The idea of using nuclear power to produce synthetic fuels, originally proposed in 1963, remains feasible today and is gaining significant attention because of recent advances in fuel cell technology, hydrogen liquefaction, and storage. At the same time, nuclear power has become a significant part of the energy supply in more than 20 countries—providing energy security, reducing air pollution, and cutting greenhouse gas emissions. The performance of the world's nuclear power plants has improved steadily and is at an all-time high. Assuming that nuclear power experiences further technological development and increased public acceptance as a safe and efficient energy source, its use will continue to grow. Nuclear power possibly could provide district heating, industrial process heating, desalination of seawater, and marine transportation.

    Demand for cost-effective chemical fuels such as hydrogen and methanol is expected to grow rapidly. Fuel cell technology, which produces electricity from low-temperature oxidation of hydrogen and yields water as a byproduct, is receiving increasing attention. Cheap and abundant hydrogen eventually will replace carbon-based fuels in the transportation sector and eliminate oil's grip on our society. But hydrogen must be produced, since terrestrial supplies are extremely limited. Using nuclear power to produce hydrogen offers the potential for a limitless chemical fuel supply with near-zero greenhouse gas emissions. As the commercial transportation sector increasingly moves toward hydrogen fuel cells and other advanced engine concepts to replace the gasoline internal combustion engine, DOD eventually will adopt this technology for its tactical vehicles.

    The demand for desalination of seawater also is likely to grow as inadequate freshwater supplies become an urgent global concern. Potable water in the 21st century will be what oil was in the 20th century—a limited natural resource subject to intense international competition. In many areas of the world, rain is not always dependable and ground water supplies are limited, exhausted, or contaminated. Such areas are likely to experience conflict among water-needy peoples, possibly prompting the deployment of U.S. ground forces for humanitarian relief, peacekeeping, or armed intervention. A mobile desalination plant using waste heat from a nuclear reactor could help prevent conflicts or provide emergency supplies of freshwater to indigenous populations, and to U.S. deployed forces if necessary.

Promising Technology for Tomorrow

    Compact reactor concepts based on high-temperature, gas-cooled reactors are attracting attention worldwide and could someday fulfill the role once envisioned for the energy depot. One proposed design is the pebble bed modular reactor (PBMR) being developed by Eskom in South Africa. Westinghouse, BNFL Instruments Ltd., and Exelon Corporation currently are supporting this project to develop commercial applications.

    A similar design is the remote site-modular helium reactor (RS-MHR) being developed by General Atomics. If proven feasible, this technology could be used to replace retiring power plants, expand the Navy's nuclear fleet, and provide mobile electric power for military or disaster relief operations. Ideally, modular nuclear power plants could be operated by a small staff of technicians and monitored by a central home office through a satellite uplink.

    The technology of both the PBMR and the RS-MHR features small, modular, helium-cooled reactors powered by ceramic-coated fuel particles that are inherently safe and cannot melt under any scenario. This results in simpler plant design and lower capital costs than existing light water reactors. The PBMR, coupled with a direct-cycle gas turbine generator, would have a thermal efficiency of about 42 to 45 percent and would produce about 110 megawatts of electricity (MWe). The smaller RS-MHR would produce about 10 to 25 MWe, which is sufficient for powering remote communities and military bases. Multiple modules can be installed on existing sites and refueling can be performed on line, since the fuel pebbles recycle through the reactor continuously until they are expended. Both designs also feature coolant exit temperatures high enough to support the thermochemical water-splitting cycles needed to produce hydrogen.

    For military applications, RS-MHR equipment could be transported inland by truck or railroad, or single modules could be built on barges and deployed as needed to coastal regions. The Army's nuclear reactor on the barge Sturgis, which provided electric power to the Panama Canal from 1968 to 1976, demonstrated the feasibility of this concept. In fact, the military previously used several power barges (oil-fired, 30-MWe power plants) during World War II and in Korea and Okinawa as emergency sources of electric power.

    Research teams around the world also are examining other reactor concepts based on liquid-metal-cooled reactor systems with conventional sodium or lead-alloy coolants and advanced water-cooled systems. The Department of Energy (DOE) is supporting research and development of innovative concepts that are based on ultra-long-life reactors with cartridge cores. These reactors would not require refueling, and they could be deployed in the field, removed at the end of their service life, and replaced by a new system. The proposed international reactor innovative and secure (IRIS) design, funded by DOE's Nuclear Energy Research Initiative, would have a straight burn core lasting 8 years and may be available by 2010. Based on increasing costs of fossil fuels, a growing consensus that greenhouse gas emissions must be reduced, and a growing demand for energy, there is little doubt that we will continue to see significant advances in nuclear energy research and development.

    Nuclear power is expected to grow in the 21st century, with potential benefits applicable to the military. Small, modular nuclear power reactors in mobile or portable configurations, coupled with hydrogen production and desalination systems, could be used to produce fuel and potable water for combat forces deployed in remote areas and reduce our logistics requirements. Assuming the inevitability of hydrogen fuel replacing fossil fuels, a clearly defined objective that was missing in 1966 now exists.

    The partnership between DOD and the former AEC to develop Army nuclear reactors contributed to the technology of both military and small commercial power plants. This historical relationship should be renewed based on recent technological advances and projected logistics requirements. DOD logistics planners should reconsider military applications of nuclear power and support ongoing DOE research and development initiatives to develop advanced reactors such as RS-MHR, IRIS, and others. For the Army to fight and win on tomorrow's distant battlefields, nuclear power will have to play a significant role.

    Would this necessarily lead to a rebirth of the old Army Nuclear Power Program, with soldiers trained as reactor operators and reactor facilities managed by the Corps of Engineers? Probably not. A more likely scenario would be a small fleet of nuclear power barges or other portable power plant configurations developed by DOE, operated and maintained by Government technicians or civilian contractors, and deployed as necessary to support the Federal Emergency Management Agency, the Department of State, and DOD. Construction, licensing, refueling, and decommissioning issues would be managed best under DOE stewardship or Nuclear Regulatory Commission oversight. As an end user of these future nuclear reactors, however, the Army should understand their proposed capabilities and limitations and provide planners with appropriate military requirements for their possible deployment to a combat zone.

Robert A. Pfeffer is a physical scientist at the Army Nuclear and Chemical Agency in Springfield, Virginia, working on nuclear weapons effects. He is a graduate of Trinity University and has a master's degree in physics from The Johns Hopkins University. Previous Government experience includes Chief of the Electromagnetic Laboratory at Harry Diamond Laboratories (HDL) in Adelphi, Maryland, and Chief of the HDL Woodbridge Research Facility in Virginia.

William A. Macon, Jr., is a project manager at the Nuclear Regulatory Commission. He was formerly the acting Army Reactor Program Manager at the Army Nuclear and Chemical Agency. He is a graduate of the U.S. Military Academy and has a master's degree in nuclear engineering from Rensselaer Polytechnic Institute. His military assignments included Assistant Brigade S4 in the 1st Armored Division.