Most of the nuclear growth is in China, the WNISR data show, where capacity grew by 3.5 gigawatts in 2024 while solar added 278 GW. “Between 2005 and 2024, there were 104 startups and 101 closures,” the report states. “Of these, 51 startups and none of the closures were in China. Thus, outside China, there has been a net decline by 48 units over the same period.”

Outside China, the report states, “nuclear generation in 2024 remained 363 TWh below the 2006 level, an almost 14% plunge.”

China is the only country with two SMR designs in operation or built, and limited operational data available. Elsewhere, they “remain largely aspirational, as despite rising public and private funding, no Western SMR construction has begun,”

Chinese and Russian governments accounted for 44 of 45 of the world’s reactor construction starts between January 2020 and mid-2025, the WNISR states. China accounted for seven of the nine construction starts in 2024.