A thrust truss has been installed at unit 1 of the El Dabaa NPP under construction in Egypt. “We have picked up a good pace of work for the speedy implementation of the main production event of this year – installation of the reactor vessel at unit 1,” said Alexey Kononenko Vice-President of Atomstroyexport (part of Rosatom) and Director of El Dabaa construction project.
El Dabaa NPP will comprise four units with Generation III+ VVER-1200 pressurised water reactors. The NPP is being constructed in accordance with contracts that entered into force in 2017. The $30bn project is mainly financed through a $25bn Russian loan. Rosatom will supply nuclear fuel throughout the lifecycle of the plant, arrange for the training of the Egyptian personnel, and assist in the operation and maintenance of the plant for the first 10 years. The reference plant for El Dabaa is the Leningrad-II NPP. Construction of all four units is planned for completion by 2028-2029, and Egypt expects that the NPP will reach full capacity by 2030.
A thrust truss is a welded metal structure that is part of the reactor shaft equipment and is designed to firmly secure it. Reliable fixation of the reactor vessel in the concrete shaft allows it to withstand seismic influences and possible pipeline ruptures, and also provides fastening in the flange area (through a thrust ring) using keys. The product was manufactured at the Tyazhmash plant in Syzran, Samara Region and delivered in sections to the construction site by sea. At the construction site it was assembled by welding 48 parallel radial beams, the outer shell and annular belts into a single annular spatial structure.
The 28.7-tonne thrust truss has a diameter of more than 6.7 metres and a height of about one metre. More than 50 specialists and a heavy crane with a lifting capacity of 2000-tonnes took part in its installation. For the first time, at a plant designed for VVER-1200 reactors, a unique technical solution was implemented – integration of a thrust truss into an enlarged reinforcement block.
For a month, specialists from contracting organisations carried out work reinforcing the structures of the reactor shaft and interfacing it with the elements of the thrust truss. This made it possible to move complex operations outside the installation area, organise the continuous installation of equipment for the melt localisation device and reactor installation, as well as ensure compliance with safety requirements, quality and construction deadlines.
Installation of a thrust truss – is another important milestone in the construction Egypt’s first nuclear power plant, said Dr Sharif Helmi Mahmoud, Chairman of the Board of Directors of Egypt’s Nuclear Power Plant Authority (NPPA). “This achievement reflects the high level of coordinated work of all project participants and demonstrates our commitment to the highest standards of safety, quality and efficiency. The El Dabaa NPP project is strategically significant for our country, and every successful step brings us closer to creating a modern facility that will contribute to Egypt’s sustainable development and energy security for decades to come.”
The next stage will be installing the reactor pressure vessel (RPV) in the design position. The RPV for unit 1 was shipped from St Petersburg in September and is scheduled to arrive at the site in November. Manufacturing of the pressure vessel took 41 months and Helmi said preparations were underway at El Dabaa’s port to allow for a safe unloading and transport process.
In a separate development, the reactor support ring has been delivered to the site. The 20-tonne support ring will be installed at a height of 11 metres in the reactor shaft and will support the weight of the reactor vessel which could weight up to 1,000 tonnes when combined with equipment and fluids.
The NPPA said the ring, made of high-strength steel alloys resistant to thermal and mechanical stress, was a key and vital component. “It transfers the entire weight of the vessel, including its equipment, nuclear fuel, and operating fluids, to the concrete base in a balanced and safe manner. It also ensures the reactor’s stability during operation and contributes to load distribution and resistance to the effects of internal pressures and earthquakes. This reflects the meticulous engineering effort involved in the design and subsequent installation of this ring.”
Dr Helmi said that the arrival of the support and stabilisation ring at this sensitive stage of the project… “reflects the national spirit and determination to achieve the Egyptian nuclear dream”. He added: “What is happening today at the Dabaa nuclear plant site … is a practical expression of Egypt’s national vision to build its own strategic capabilities and enhance its pioneering role regionally and globally in the field of peaceful uses of nuclear energy.”
