Nuclear energy is commonly defined as the energy released by a chain reaction, such as fission or fusion. Nuclear energy, in practice, generates steam and power using fuel produced from mined and processed uranium. We have more cost-effective and creative ways to harvest and store wind and solar energy but nuclear power is the only form of energy that can provide a consistent supply of electricity, which is referred to as baseload power. —reliably without emitting greenhouse gases. The thermal energy from nuclear reactors may also be used to decarbonize other energy-intensive sectors such as transportation – the largest contributor to carbon pollution. In 2019, nuclear plants operated at full power more than 92% of the time, making it the most reliable energy source. DOE and its national labs are working with industry to develop new reactors and fuels that will increase the overall performance of these technologies and reduce the amount of nuclear waste that is produced. To improve operating costs, DOE is also working with the industry to develop new fuels and cladding known as accident tolerant fuels. These new fuels could increase plant performance, allowing for longer response times, and will produce less waste. Accident-tolerant fuels could gain widespread use by 2025.