Nuclear Batteries for Maritime Applications

The large size of the ocean stretches the capability of conventional power sources beyond their limits. Chemical batteries simply do not have enough energy density to power underwater unmanned vehicles (UUVs) for hundreds of miles or oceanic sensors for months on end. Wave and solar energy harvesters are traditionally limited to the surface and cannot provide power to deep water devices. A new type of power supply must be developed if the deep oceans are to be completely mapped and explored. One source of energy that has the power density needed is that of the radioisotope power supply or nuclear battery. This concept draws on the benefits of nuclear power in batteries—just like nuclear submarines use nuclear reactors. Nuclear batteries have energy densities thousands of times greater than chemical cells and can provide power nonstop for months to centuries, depending on the isotope used. Radioisotope batteries do not suffer from the temperature and pressure limitations that conventional batteries do. However, current nuclear battery designs are far too expensive for commercial use and are limited to high-profile applications like space power. A new type of nuclear power supply needs to be developed in order to completely take advantage of radioisotope battery benefits. The authors are developing such a system that makes use of the thermionic energy conversion to create an efficient, cost-effective, and safe nuclear battery, specifically for oceanic applications.