At the end of last month, the most important safety barrier of Unit 1 of Sanmen Nuclear Power Station, the reactor pressure vessel, was successfully hoisted, marking the world's first AP1000 nuclear power unit to fully enter the critical main equipment installation phase.
The pressure vessel is located in the center of the reactor building and is capable of containing and supporting the reactor core, which is known as the heart of the nuclear power plant. It is difficult to manufacture and has a long cycle. The quality of manufacturing is directly related to the intrinsic safety level of nuclear power plants. The hoisted pressure vessel was designed by Westinghouse, USA, and is the world's first AP1000 nuclear power reactor reactor pressure vessel. Under the major special support of large-scale nuclear power plants, China Yizhong Group and other units successfully manufactured large-scale forgings for pressure vessels on the basis of overcoming key technologies such as large forging smelting, profile forging, forming and heat treatment processes, and produced them by Doosan Heavy Industries of Korea. The ultimate pressure vessel. The installation of the world's first AP1000 pressure vessel marks that China has broken through the three-generation nuclear power key equipment forging manufacturing technology, breaking the monopoly of foreign companies in the high-end large-scale casting and forging market, laying a solid foundation for the comprehensive localization of the key technologies of the three generations of nuclear power.
The three-door nuclear power project adopts AP1000's unique prefabricated and modular construction method of building blocks. The procedures of civil engineering, installation and commissioning are deeply crossed, which increases the difficulty of equipment installation. The internal structure of the reactor building itself is complex, and the pressure vessel is hoisted. The technical requirements of the work are extremely high. The pressure vessel is erected to be equivalent to a three-storey building. When hoisting, it needs to cross the temporary roof of a steel containment that is 52 meters above the ground. It must also miss the insulation layer in the 155 mm gap for construction work. With the support of major national science and technology projects, China Nuclear Fifth Construction Co., Ltd. and other units have overcome difficulties and took the lead in mastering this hoisting technology, further consolidating China's international leading position in the AP1000 engineering construction technology field.