By: Roger Reynolds, Senior Technology Advisor
When TerraPower settled on nuclear energy as the best solution to combat climate change and global poverty, we recognized several areas of nuclear technology that could benefit from improvement. These included increased energy production, energy security and resistance to proliferation. Part of the solution, we found, was to extend the length of time fuel remains in the core of a reactor.
Setting this goal for ourselves meant that we also presented ourselves with a significant challenge. The integrity of the fuel and the ability of surrounding materials to withstand a harsh environment dictate how well we can extract the energy from the fuel. Today’s light water reactors only extract about 5 percent of the energy potential from their fuel. To do better, we essentially needed to invent new metals and new fuel configurations. Each step in our fuels and materials research has brought us closer to this goal.
We succeeded this year with the fabrication of the first fast reactor fuel assembly for the traveling wave reactor (TWR). This full-sized proof, manufactured through an agreement with AREVA Inc., is five meters long and is specially designed to hold TWR fuel. We’re incredibly proud of this accomplishment, as it marks a significant milestone in our journey to a prototype reactor.
Unlike the technology widely used today, TerraPower’s fuel assembly is designed to hold primarily depleted uranium. It also uses materials that can withstand the harsh core environment, immersed in a liquid sodium bath, for a minimum of 10 years. Compare this to the light water technology of today – fuel assemblies contain enriched uranium and must be replaced every 18 to 24 months.
I’ve been in the nuclear fuel business for a long time and TerraPower’s research and development continues to stand out. I attribute the rapid prototyping to the influence of our multidisciplinary team. Our experts from the computer science realm are accustomed to rapid-fire product cycles for software development and we’ve borrowed some worthwhile practices to accelerate nuclear energy’s advancement.