Unit 4 of CGN's Zhejiang Sanao Nuclear Power Project officially commences construction

Recently, the first concrete pouring for the nuclear island of Unit 4 of the Sanao Nuclear Power Project in Wenzhou, Zhejiang Province officially began, marking the full commencement of the unit's main works and the official entry of the project's Phase II into the stage of large-scale construction. As the first “Hualong One” project in the Yangtze River Delta region and the country's first nuclear power project to introduce private capital participation, the continued advancement of the Sanao Nuclear Power Project has set an important example for the high-quality development of clean energy in China.

Located in Wenzhou, Zhejiang Province, the Sanao Nuclear Power Project is the first “Hualong One” project in the Yangtze River Delta region and the country's first nuclear power project to introduce private capital participation. Unit 4, which commenced construction this time, is part of Phase II of the Sanao Nuclear Power Project and is the third nuclear power unit officially started by CGN this year. It was approved by the state on August 19, 2024, and adopts China's fully independent intellectual property rights “Hualong One” third-generation nuclear power technology. Upon completion, it is expected to generate up to 9 billion kWh of electricity annually, sufficient to meet the annual production and living electricity demand of approximately 1 million people.

The total volume of concrete poured this time is approximately 8,820 cubic meters, expected to last 60 hours. The on-site team will anchor to the goal of “each unit better than the last” and, on the premise of ensuring safety and quality, continuously ensure the high-quality progress of construction milestones on schedule through multiple measures such as process iteration and optimization, intelligent tooling upgrades, and minor improvements. Since the start of project construction, multiple advanced technologies such as prefabricated removable retaining walls and embedded part hot heading technology have been applied. Going forward, advanced construction technologies such as modular construction and automatic welding will continue to be applied, providing more replicable and promotable construction experience for similar nuclear power projects.

A major innovation highlight of this construction is reflected in the large-scale application of intelligent equipment. In response to issues such as the large processing volume of nuclear island components and fittings and the difficulty of manual processing precision control, the project team has built supporting automated production lines for rebar and embedded parts, and deployed intelligent equipment including embedded part welding robots, stool bar welding robots, and automatic anchor block installation platforms. By replacing traditional manual operation modes with automated processing and assembly, the quality of component processing and production efficiency have been effectively improved. Among them, the embedded part welding robots and stool bar welding robots can increase the one-time welding qualification rate to 90% and increase welding efficiency by approximately 2 times and 4 times respectively; the automatic anchor block installation platform will increase the one-time qualification rate of anchor plate installation to 100% and increase installation efficiency by approximately 11.5 times. The large-scale application of intelligent equipment in the project has demonstrative significance for promoting efficient, intelligent, and industrialized nuclear power engineering construction.

The Sanao Nuclear Power Project plans to build six “Hualong One” units in three phases, with four units currently approved. Among them, Unit 1 has been officially put into operation and connected to the grid, Unit 2 has completed its first nuclear fuel loading, and Unit 3 is undergoing main structure construction of the buildings surrounding the nuclear island. Overall construction is progressing steadily as planned. After all six units are completed, the annual power generation capacity is expected to exceed 54 billion kWh, close to 80% of Wenzhou's current total annual electricity consumption. Each year, it can equivalently reduce standard coal consumption by more than 16.35 million tons and reduce carbon dioxide emissions by nearly 50 million tons. As an important clean energy base in the southern wing of the Yangtze River Delta, the Sanao Nuclear Power Project will focus on the strategic deployment of the “15th Five-Year Plan” regarding the coordinated layout of green electricity and computing power, providing solid support for the green and low-carbon transformation of the Yangtze River Delta as well as the high-quality development of computing power hubs and the intelligent economy.