Kurt Terrani wants to accelerate the future of nuclear energy – so he turned to her past. For the past year and a half, Terrani and a team of physicists, engineers, and computer scientists from the Oak Ridge National Lab in Tennessee have designed and built the components for a gas-cooled nuclear reactor. It’s a type of reactor that’s almost as old as the atomic age itself, but Oak Ridge’s latest atomic divider has a characteristic twist on the 21st century. When it goes online in 2023, it will be the world’s first nuclear reactor with a 3D printed core.
“We are trying to find a faster way to build a nuclear system with superior performance,” said Terrani, technical director of the Oak Ridge Transformational Challenge Reactor program. “The goal is to fundamentally change the way we operate nuclear weapons.”
The nuclear industry has a reputation for being incredibly conservative and resistant to change, and Terrani complains that all American nuclear reactors still use technology that was invented half a century ago. The “if it ain’t broke, don’t fix it” mindset is a way to manage the inherent risk and exorbitant cost of building new nuclear power plants, but it also suppresses innovation in an industry that consumes most of the American carbon delivers. free energy. Terrani fears that if the nuclear industry does not accept new technologies, it will soon be out of date.
This does not mean that we should start building experimental nuclear power plants without care. The reason why the nuclear industry is moving so slowly is that the price of a misjudgment is enormous – the accidents in Chernobyl and Fukushima were generational catastrophes that nobody wants to repeat. However, risk aversion has not prevented other notoriously stuffy industries from using new technologies. Just look at the aerospace industry, where companies are now printing whole rockets in 3D, flying self-landing planes, and catching boosters on drone ships. In addition, most of the advanced reactors under development are not entirely new. These are modified designs of reactors that were successfully built decades ago. “We know that all of these concepts work,” says Terrani. “The problem is that we cannot build them quickly and cheaply enough.”
Terrani and his colleagues are working on it. The Oak Ridge team recently completed the preliminary design for the 3D printed core at the heart of its Transformational Challenge Reactor (TCR). Although most of the reactor will consist of conventional components, the core will be printed entirely in 3D from silicon carbide, an extremely robust material that is virtually impossible to melt. The cylindrical core is a matt metallic silver with several irregular non-fuel elements in the middle. This is where all the magic happens in a nuclear reactor: it is responsible for holding the uranium fuel and the components that control the fission reaction. The core, designed and printed at Oak Ridge, is less than a foot and a half tall and is housed in a reactor that is not much larger than a beer keg. However, if it goes online in 2023, Terrani says it will generate up to 3 megawatts of electricity, enough to meet the energy needs of more than 1,000 average households.
The TCR is an advanced gas-cooled reactor that uses helium as a coolant, while most of the operational reactors in the U.S. today use water. Gas-cooled reactors are extremely economical in fuel consumption because they operate at very high temperatures – this runs at around 1,200 degrees Fahrenheit – and Terrani says that 3D printing of the reactor core will further increase efficiency. In addition, traditional machining techniques to build a reactor core limit their construction. The complex network of cooling channels in the Oak Ridge core is too small and tortuous for conventional machining techniques. Because 3D printers create an object by fusing metal layer by layer, engineers can create core designs that were previously impossible.