Significant progress has been made in the construction of new nuclear power units in China, with key components recently installed at two major sites.
The reactor pressure vessel top cover has been successfully hoisted into place at Unit 1 of the San’ao nuclear power plant in Zhejiang province, while the first steam generator has been installed at Unit 8 of the Tianwan plant in Jiangsu province.
Reactor Pressure Vessel Cover Installed at San’ao Unit 1
On August 6, the reactor pressure vessel top cover was installed at San’ao Unit 1 in an operation that took approximately two hours, according to the China National Nuclear Corporation (CNNC).
This successful installation marks a significant milestone in the construction of the San’ao nuclear power project, which is being overseen by CNNC’s subsidiary, CNNC No. 5.
The operation is seen as a demonstration of the company’s strong capabilities in nuclear power construction.
The installation of the reactor pressure vessel cover is a crucial step in the construction of San’ao Unit 1, which is the first of six HPR1000 (Hualong One) pressurized water reactors planned for the site.
The successful placement of this component lays a solid foundation for subsequent cold testing, signaling that the construction of Unit 1 has now entered a new and critical phase.
The San’ao project received approval from the National Energy Administration in May 2015 to begin site protection and related demonstration work.
The State Council approved the construction of Units 1 and 2 as the first phase of the plant on September 2, 2020. Following this, China’s National Nuclear Safety Administration issued a construction permit for the two units on December 30, 2020, and the first concrete for Unit 1 was poured the very next day.
The first concrete for Unit 2 followed a year later, on December 30, 2021.
The reactor pressure vessel for Unit 2, including its top cover, was delivered to the construction site earlier this month, indicating that work on this unit is also progressing according to schedule.
San’ao Units 1 and 2 are expected to begin supplying electricity in 2026 and 2027, respectively.
Installation of the First Steam Generator at Tianwan Unit 8
On August 11, the first of four steam generators was successfully installed at Tianwan Unit 8, as announced by China Nuclear Power Engineering Co (CNPEC), a subsidiary of CNNC.
The steam generator is a critical component of the primary circuit system in a nuclear power plant. It weighs approximately 330 tonnes, measures over 14 meters in length, and has a maximum diameter of 4.5 meters.
The steam generator functions as a heat transfer device, transferring heat from the primary circuit coolant to the feed water in the secondary circuit.
This process generates saturated steam that drives the steam turbine generator. Additionally, as part of the primary circuit pressure boundary, the steam generator withstands the pressure of the primary circuit coolant, making it an essential component in the plant’s operation.
The Tianwan nuclear power plant is operated by Jiangsu Nuclear Power Company, a joint venture between CNNC (50%), China Power Investment Corporation (30%), and Jiangsu Guoxin Group (20%).
In June 2018, Russia and China signed four agreements, including one for the construction of two VVER-1200 reactors at the Tianwan plant as Units 7 and 8.
These units are scheduled to be commissioned between 2026 and 2027.
The steam generators for Tianwan Unit 8 were manufactured at the Atommash production facility in Volgodonsk, southern Russia.
After being produced, the components traveled thousands of miles, including a two-month sea voyage, to reach their final destination on the Chinese coast. This installation marks a significant step forward in the construction of Tianwan Unit 8, contributing to the overall progress of the project.