Major components installed at new Chinese units

Wednesday, 14 August 2024

China National Nuclear Corporation (CNNC) said the vessel cover was installed at San'ao 1 on 6 August in an operation lasting about two hours.

"The successful completion of the first buckling of the reactor pressure vessel cover is another demonstration of the nuclear power construction capabilities of [CNNC subsidiary] CNNC No.5, laying a solid foundation for the subsequent cold test work, and also marks that the construction of the No.1 unit of the CGN San'ao Nuclear Power Project has entered a new stage," the company said.

San'ao 1 is the first of six Chinese-designed HPR1000 (Hualong One) pressurised water reactors planned at the site.

In May 2015, the National Energy Administration approved the project to carry out site protection and related demonstration work at San'ao. On 2 September 2020, the executive meeting of the State Council approved the construction of units 1 and 2 as the first phase of the plant. China's National Nuclear Safety Administration issued a construction permit for the two units on 30 December that year and first concrete for unit 1 was poured the following day. The first concrete for San'ao 2 was poured on 30 December 2021.

The reactor pressure vessel for unit 2, including the top cover, was delivered to the construction site earlier this month.

San'ao 1 and 2 are scheduled to begin supplying electricity in 2026 and 2027, respectively.

Tianwan steam generator in place

The first of four steam generators was hoisted into place at Tianwan unit 8 on 11 August, CNNC subsidiary China Nuclear Power Engineering Co (CNPEC) announced.

The steam generator is installed at Tianwan 8 (Image: CNPEC)

The steam generator is the main equipment of the primary circuit system. Its single unit weight is about 330 tonnes, its length over 14 metres, and its maximum diameter is 4.5 metres.

As a heat transfer device, it is used to transfer the heat in the primary circuit coolant to the feed water of the secondary circuit, so that it can generate saturated steam for driving the steam turbine generator. At the same time, as part of the primary circuit pressure boundary, it bears the pressure of the primary circuit coolant.

The Tianwan nuclear power plant is owned and operated by Jiangsu Nuclear Power Company, a joint venture between China National Nuclear Corporation (50%), China Power Investment Corporation (30%) and Jiangsu Guoxin Group (20%). In June 2018, Russia and China signed four agreements, including for the construction of two VVER-1200 reactors as units 7 and 8 of the Tianwan plant. They are scheduled to be commissioned in 2026-2027.

The steam generators for Tianwan 8 were produced at the Atommash production site in Volgodonsk in southern Russia and travelled thousands of miles - including two months at sea - to the end location on the Chinese coast.