Fusion start-ups are deliberately avoiding the term 'nuclear' to distinguish their technology from conventional nuclear power. Companies like Commonwealth Fusion Systems and Helion Energy argue that fusion, which joins atomic nuclei rather than splitting them, does not carry the same risks as fission. This branding strategy is paying off as US regulators prepare rules that would place fusion under a lighter licensing regime, similar to particle accelerators.

The Nuclear Regulatory Commission is finalising these rules, which could allow many projects to fall under state rather than federal oversight. The Fusion Industry Association and its chief executive, Andrew Holland, have been leading voices in advocating for this separation. The industry has attracted more than $11.5bn in private funding, with backers including Google, Microsoft, and OpenAI CEO Sam Altman.

While a US government laboratory has demonstrated net energy gain, no company has yet built a commercially viable power plant.