The Japan Atomic Energy Agency (JAEA) is pioneering a cutting-edge nuclear battery designed to last over a century, utilizing the decay heat from americium—a byproduct of nuclear waste—to generate electricity. The innovation is targeted at powering space probes in environments where solar energy is ineffective, such as asteroids, the far reaches of the solar system, or the Moon’s shadowed regions.
Strategic Collaboration with JAXA and AIST
This groundbreaking initiative is being undertaken in partnership with the Japan Aerospace Exploration Agency (JAXA) and the National Institute of Advanced Industrial Science and Technology (AIST). Backed by government support, the JAEA plans to unveil a working prototype by 2029. The collaboration aims to create a compact, reliable energy solution for deep-space exploration.
Americium: The Power Source
Americium, formed from the natural decay of plutonium in spent nuclear fuel, is less energetic than plutonium but offers strategic benefits. Unlike plutonium, which faces heavy legal restrictions in Japan, americium is more feasible to work with domestically. Despite its lower heat output, it still provides enough energy for long-term missions and could potentially power spacecraft instruments and communication systems for decades.
Masahide Takano, a senior researcher at JAEA’s NXR Development Center, noted that americium-based batteries could significantly extend the operational life of space missions, making them a promising alternative to traditional power sources.
Extracting and Containing Americium Safely
To ensure a reliable supply of americium, the JAEA has developed a method to extract it from uranium-plutonium mixed oxide (MOX) fuel, which it already has in stock. For safety, the americium is processed into solid pellets mixed with stabilizing agents and sealed inside metal casings. This containment system is designed to prevent radiation leaks even in the event of a rocket launch failure.
Early Success and Proof of Concept
The JAEA has already showcased the viability of this technology by using americium to power LED lights through a semiconductor-based energy conversion method. This demonstration proves that americium can serve as a dependable, long-lasting power source.
Looking Ahead
With a prototype expected by 2029, the nuclear battery will be compact and lightweight, engineered to endure the harsh conditions of space—including extreme temperatures and vacuum exposure. The joint efforts of JAEA, JAXA, and AIST are driving this project forward, aiming to revolutionize power systems for space missions where solar power falls short.
This breakthrough represents a significant milestone in space technology, potentially enabling humanity to explore deeper and farther into the cosmos than ever before.