What type of energy source is characterized by releasing energy without significant carbon emissions during operation?

Nuclear energy is characterized by releasing energy without significant carbon emissions during its operation. This is because nuclear power plants generate electricity through a process called nuclear fission, where the nuclei of heavy atoms, such as uranium, are split to release energy. The process does not involve combustion, which is responsible for the carbon emissions associated with fossil fuels like coal, natural gas, and oil.

In addition to the absence of direct carbon emissions during operation, nuclear energy offers a high energy density, meaning that a relatively small amount of fuel can produce a large amount of energy. This feature enhances its efficiency as a power source while contributing to climate change mitigation efforts, as it does not contribute to greenhouse gas emissions in the same way that burning fossil fuels does.

Although there are other environmental considerations related to nuclear energy, such as radioactive waste management and the potential for accidents, the defining aspect of nuclear energy in the context of this question is its operational carbon neutrality.