Commissioning milestones at Chinese AP1000s

Friday, 17 August 2018

Unit 2 of the Sanmen nuclear power plant in China's Zhejiang province attained first criticality - a sustained chain reaction - at 12.07am today, China National Nuclear Corporation (CNNC) and State Nuclear Power Technology Corporation (SNPTC) announced.

After completing a series of low-power physics tests, the unit's turbines will be driven for the first time using nuclear-generated steam. The next stage in the commissioning of Sanmen 2 will be synchronisation to the electricity grid. This will be followed by gradual power ascension testing until all testing is safely and successfully completed at 100% power.

Meanwhile, unit 1 at the Haiyang plant in Shandong province was connected to the electricity grid at 9.50am today and began power generation.

Unit 1 of the Haiyang plant (Image: Westinghouse)

SNPTC said the unit will now enter a load test operation state, during which further tests will carried out at 5% rated power, 50% rated power and 90% of rated power. On completion of these stages, CNNC will then seek approval for commercial operation of the unit.

In September 2007, Westinghouse and its partner the Shaw Group received authorisation to construct four AP1000 units in China: two at Sanmen and two more at Haiyang in Shandong province. Construction of Sanmen 1 began in April 2009, while first concrete for Sanmen 2 was poured in December 2009. Construction of Haiyang 1 and 2 began in September 2009 and June 2010, respectively.

Sanmen 1 was the world's first AP1000 to start up, achieving first criticality on 22 June and grid connection on 2 July. It reached full power operation for the first time on 14 August.

Unit 1 of the Haiyang plant attained first criticality on 8 August, the same day the loading of the 157 fuel assemblies into the core of unit 2 began.

Four AP1000 reactors were also being built in the USA - two each at Vogtle and Summer. However, construction of the two Summer units was suspended last August.