The primary form of energy used in nuclear power plants is nuclear energy. This energy is generated through a process called nuclear fission, where the nuclei of heavy atoms, such as uranium-235 or plutonium-239, are split into smaller parts. This reaction releases a significant amount of heat, which is used to produce steam that drives turbines, generating electricity. Nuclear power is a low-carbon energy source, making it an important part of the global energy mix as countries seek to reduce greenhouse gas emissions. However, it comes with challenges, including radioactive waste management and safety concerns associated with reactor operations.