The 1,000-MW pressurised water reactor achieved the milestone at 19:52 local time on 8 August, CNNC said.
The unit, which achieved first criticality on 27 July, will now undergo tests at 30%, 50% and 100% of its generating capacity before entering a full power demonstration operating assessment, CNNC said. During this assessment stage, performance indicators will need to meet design standards and the requirements of the power grid, which will indicate that the unit has achieved formal commercial operating conditions.
Fuel loading at Tianwan-5 took place on 9 July, marking the first nuclear power unit under construction in China to accomplish fuel loading this year.
Tianwan-5 is a domestically developed CNP-1000 design. It is seen as a Generation II+ design and a precursor to Generation III designs.
Another unit of the same design, Tianwan-6, is also under construction at the site.
Construction of Tianwan-5 began in December and of Tianwan-6 in September 2016.
There are also four Russia-procured VVER-1000 nuclear units in commercial operation at Tianwan.