Welding starts of main circulation pipeline in unit 1 of Turkey’s first nuclear plant 

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Welding of the main circulation pipeline has started in unit 1 of Turkey’s first nuclear power plant (NPP) at Akkuyu being constructed with the assistance of the Russian state atomic energy corporation Rosatom. 

The main circulation pipeline connects the major equipment of a nuclear power plant (NPP) – reactor, steam generators, reactor coolant pumps – and is a part of the primary circuit of a nuclear power plant (NPP).  

A Rosatom statement earlier this week described the welding of the main circulation pipeline as one of the key stages in the construction of the reactor unit. 

“During the NPP operation, water at a temperature up to 330 degrees Centigrade continuously circulates through it. Only special pipes with 70 mm wall thickness can withstand such loads, therefore, pipeline welding is a complex and high-tech operation, which is subject to the most stringent requirements. The completion of the welding operation will be the starting point for open reactor circulation tests”, Rosatom subsidiary Akkuyu Nuclear’s CEO Anastasia Zoteeva said in a statement. 

The statement said the installation of the main circulation pipeline includes not only assembly and welding of pipes, “but also high-temperature treatment of joints followed by a special build-up welding on the inside of the pipeline”. This provides corrosion resistance to the pipeline, increases durability of welded joints and ensures the pipeline’s operating lifetime of at least sixty years, as stipulated by the project design.  

During the installation, specialists will have to weld 28 pipeline joints, assemble about 260 tons of pipes and steel structures, as well as to perform quality control of the welded joints , the statement added.  

Last year, the reactor pressure vessel was installed at unit 1 of the Akkuyu NPP, while four steam generators for the second unit were also shipped from Russia following the completion of their manufacture. 

During 2021, Rosatom had also announced that construction work had started on the units 3 and 4 of the Akkuyu NPP. A Rosatom statement had said that building and installation works were being carried out simultaneously at the construction sites of all four Akkuyu NPP power units, making it the world’s largest nuclear construction site with four power units being built simultaneously. 

The statement had said that the Akkuyu NPP is the first project in the global nuclear industry that is being implemented according to the Build-Own-Operate model. 

According to Turkish Energy and Natural Resources Minister Fatih Dönmez, “construction and commissioning of the plant will provide 10 percent of Turkey’s electricity needs. It is also an important contribution to the preservation of our ecology: nuclear power plants are a source of environmentally friendly and uninterrupted electricity. The project is a driver for the development of industry, economy, employment, and also contributes to the development of many related industries.”      

Turkey plans to bring the 1,200 MW unit 1 online in 2023. With three more similar units, the Akkuyu NPP will have a total capacity of 4,800 MW. All the units are to be equipped with the state-of-the-art Generation III+ VVER-1200 reactors.