China uprates its oldest reactor

The uprate was announced after the plant had successfully completed a proving test involving 168 hours of "safe and stable" operation.

Qinshan 1, a pressurised water reactor brought online in 1991, was the first nuclear power unit China built using its own technologies. It went on to import several larger designs from countries that were more established in nuclear power at the time. China is now self-sufficient in nuclear power generation and has rolled out a series of large nuclear reactors of its own design and supported by its own supply chain.

CNNC said the engineering work "has important reference significance for the power enhancement of subsequent power stations, and plays an exemplary role in the life management of domestic nuclear power plants."

Qinshan's operational conditions have been stable and performance indicators have been "excellent" since the unit was first connected to the grid on 15 December 1991, CNNC said. According to the latest data shared with the International Atomic Energy Agency, Qinshan 1 achieved a load factor of 100.2% in 2017 and has averaged 83.5% over its whole lifespan. CNNC said it has "achieved good performance and economic benefit."

In addition, the reactor has been a test-bed for the Chinese industry, with over 130 technical updates and improvements per year, CNNC said. Its achievements include a continuous generation run of 469 days in 2007 and a national record refuelling outage of just over 18 days in 2014.

CNNC did not detail how the additional 50 MWe gross output was achieved. General information from the US Nuclear Regulatory Commission suggests that at 16% it is likely to be what is called an 'extended uprate', which involves significant modifications to major pieces of non-nuclear equipment such as high-pressure turbines, condensate pumps and motors, main generators and transformers. Extra power on a smaller scale can also be obtained by reducing measurement uncertainty and refining a plant's operating margins.