The generation of electricity through nuclear fission or fusion reactions. Nuclear energy offers high energy density and low carbon emissions but raises questions about safety, waste disposal, and proliferation risk.
Nuclear power generates electricity with lifecycle carbon emissions comparable to wind and solar, and can provide reliable, high-density baseload power that accelerates the displacement of coal and gas without intermittency problems.
The decades-long lead times and high capital costs of nuclear construction mean that new plants will not contribute meaningfully to near-term emissions reductions, when the next fifteen years are most critical for climate trajectories.
Per unit of energy produced, nuclear power kills far fewer people than fossil fuels and is statistically comparable to wind and solar; major accidents are rare, and modern reactor designs incorporate passive safety features that make meltdown scenarios far less likely.
While accidents are infrequent, their potential consequences — long-lived radioactive contamination across large areas, as at Chernobyl and Fukushima — are qualitatively different from other energy risks and can displace populations for generations.
Nuclear waste is physically compact — a product of its extraordinary energy density — and can be safely contained in engineered storage facilities for the centuries needed before radioactivity decays to safe levels.
No country has yet opened a permanent deep geological repository for high-level nuclear waste, leaving accumulating spent fuel at surface sites with unresolved institutional challenges for monitoring over the millennia-long timescales required.
Civilian nuclear programs operate under international safeguards and inspection regimes that distinguish peaceful energy use from weapons development, and many countries have maintained civilian nuclear programs without pursuing weapons.
The spread of enrichment and reprocessing capabilities through civilian nuclear expansion creates a latent proliferation risk, as the same technologies that produce reactor fuel can, with modification, produce weapons-grade material.