A nuclear reactor at the centre of an $8bn US-Chinese partnership and technology transfer agreement has delivered its first electricity to the Chinese grid, even as the countries square off in a looming trade war that threatens to derail future co-operation and stall US efforts to reboot its nuclear industry.

The Sanmen nuclear power plant, designed by Westinghouse, is the first in a series of AP1000 reactors that China agreed to license and build in a deal signed in 2006.

As part of the arrangement, SNPTC, the Chinese state nuclear group that partnered with Westinghouse, was allowed to build smaller or bigger reactors that they could then export as Chinese technology. In theory, this would have allowed the country to build a nuclear power export industry.