GoKawiilThese methods are how the nuclear industry safely manages the 10,000 metric tons of spent fuel waste that reactors produce as they churn out 10% of the world’s electricity every year. But as new nuclear designs emerge, they could introduce new wrinkles for nuclear waste management.
Most operating reactors at nuclear power plants today follow a similar basic blueprint: They’re fueled with low-enriched uranium and cooled with water, and they’re mostly gigantic, sited at central power plants. But a large menu of new reactor designs that could come online in the next few years will likely require tweaks to ensure that existing systems can handle their waste.
“There’s no one answer about whether this panoply of new reactors and fuel types are going to make waste management any easier,” says Edwin Lyman, director of nuclear power safety at the Union of Concerned Scientists.
A nuclear disposal playbook
Nuclear waste can be roughly split into two categories: low-level waste, like contaminated protection equipment from hospitals and research centers, and high-level waste, which requires more careful handling.
The vast majority by volume is low-level waste. This material can be stored onsite and often, once its radioactivity has decayed enough, largely handled like regular trash (with some additional precautions). High-level waste, on the other hand, is much more radioactive and often quite hot. This second category consists largely of spent fuel, a combination of materials including uranium-235, which is the fissile portion of nuclear fuel—the part that can sustain the chain reaction required for nuclear power plants to work. The material also contains fission products—the sometimes radioactive by-products of the splitting atoms that release energy.
Many experts agree that the best long-term solution for spent fuel and other high-level nuclear waste is a geologic repository—essentially, a very deep, very carefully managed hole in the ground. Finland is the furthest along with plans to build one, and its site on the southwest coast of the country should be operational this year.
The US designated a site for a geological repository in the 1980s, but political conflict has stalled progress. So today, used fuel in the US is stored onsite at operational and shuttered nuclear power plants. Once it’s removed from a reactor, it’s typically placed into wet storage, essentially submerged in pools of water to cool down. The material can then be put in protective cement and steel containers called dry casks, a stage known as dry storage.
Experts say the industry won’t need to entirely rewrite this playbook for the new reactor designs.