From the beginning, TerraPower committed to take a leap, not a step, toward exploring technologies. Incremental improvements gave way to innovation where it would matter most.
The company’s founders knew it would take technology leaps to produce more clean energy to reduce poverty and its impacts. Recent progress on the company’s multiple reactor pathways shows TerraPower continues to advance its goals and is doing its part to make sure the right technologies are available at the right moments. As the Wright brothers proved in Kitty Hawk, North Carolina, it is these moments that history marks technology leaps.
From TerraPower’s contributions to the Versatile Test Reactor program to its launch of the Natrium™ technology with GE Hitachi Nuclear Energy to its expanded work on the molten chloride fast reactor, its teams keep challenging common assumptions about nuclear science and technology. No matter what line of business, TerraPower’s advancements in reactor design, software automation, medical isotopes, process heat and storage applications inspire new, positive outlooks for the future.
TerraPower began its pursuits with the traveling wave reactor because it was not a step but a leap – an ambitious concept that had a good track record of success. TerraPower’s work on nuclear innovation centers on technologies that fill varied customer needs. But one thing many of them share – fast neutrons.
Why fast reactors?
Fast reactors originated in the United States and were operated by both government and private interests. Today, they continue to operate in Russia, France and China. When you go fast, you quickly gain benefits and fuel options.
Let’s look at the differences. Today’s operating fleet of reactors are water cooled and called light water reactors. Water is called light because of the hydrogen – after fission occurs, a fast neutron comes out. When it hits the water, it bounces and the water molecules bounce, too. That’s what makes water a moderator – it slows the neutrons. Neutrons are “born” fast but slow quickly.
Fast reactors differ because they don’t slow the neutrons. And because fast neutrons can cause fission, fast reactors can increase reactor efficiency. That’s why a different coolant than water is needed.
Fission products give off energy in the form of fast neutrons – and the heavier the element, the more you can retain that energy.
What about waste?
Historically, fast reactors have been associated with reprocessing, known as closing the fuel cycle, to get more energy from fuel. It’s easy to overlook that reprocessing can be done with light water reactors not just fast reactors. France, Japan, Switzerland and several other countries ship their fuel back to be renewed and returned to operating reactors as fuel.
Respecting the history of concerns about the misuse of nuclear material, TerraPower focused on burning depleted uranium and reduced the need for both enrichment and reprocessing with extraordinary fuel designs. This has allowed the company to address both proliferation and waste.
Better material science also opened new options for TerraPower. High energy neutrons are tough on materials. The team knows that with stronger materials, they could run the reactor longer and burn the fissile material. In fact, TerraPower’s early work on improving steel alloys informed the design for the Natrium technology.
From what it learned from testing materials in a fast reactor in Russia, TerraPower can maximize the energy from its fuel within the reactor core. And now, the company is looking forward to seeing the U.S. Department of Energy develop even more versatile testing capabilities in the United States to help look more closely at materials’ behavior in advanced reactors.
People have been operating fast reactors around the world for 70 years. The data and knowledge collected have provided invaluable inputs into modern design tools. Now, those innovations are making their way back into relevance as nuclear energy seeks to reach its full potential. Reducing nuclear waste without reprocessing is another benefit the TerraPower team is excited to see coming to realization with their technologies.