Power Unit No. 2 Steam Generators Delivered to Akkuyu NPP Site
January 15, 2022, Büyükeceli, Mersin Province, Turkey. – A set of 4 steam generators for Akkuyu NPP Power Unit No. 2 has been delivered to the Eastern Cargo Terminal. After a cargo vessel had been successfully unloaded by heavy caterpillar crane, the steam generators were transported to the temporary equipment storage site where special committee will carry out incoming inspection, verifying the quality and completeness of equipment.
The steam generators were delivered from Russian manufacturer Atommash JSC by road to the port located on the Tsimlyansk Reservoir bank, where they were loaded onto the cargo vessel. The vessel then left Volgodonsk, went down the Don River, entered the Azov Sea, crossed the Black Sea, the Sea of Marmara, the Aegean Sea and the Mediterranean Sea to finally reach its destination point, the Eastern Cargo Terminal located at the Akkuyu NPP Construction Site. The sea route distance was about 3 000 km, while the gross weight of the consignment exceeded 1 800 tons.
"Large-size equipment for Akkuyu NPP is normally transported in multimodal way, by land and sea, so the carrier takes a large number of caveats into account, thoroughly considers the cargo route and controls each loading stage. For instance, for the transportation of this steam generator consignment, dredging works were additionally arranged near the Tsimlyansk Reservoir quay. By the way, preparation for installing the steam generators in the reactor compartment of the Unit No. 1 is almost complete. Following their installation, we will commence the key operation – welding of the reactor cooling pipeline which connects main equipment of the primary circuit," commented Sergei Butсkikh, AKKUYU NUCLEAR JSC First Deputy Chief Executive Officer and Director of the NPP under Construction.
The steam generators are a part of the main equipment of the NPP's primary circuit. The primary circuit also includes the nuclear reactor, reactor coolant pumps, reactor coolant pipeline, pressurizer and set of safety systems. Steam generator is a 355-ton heat-exchanging unit where horizontally arranged tubes are completely submerged in the coolant, which is chemically demineralized water. The primary coolant is circulating inside heat-exchanging tubes. The upper part of the housing has a space where steam is generated, and the lower part contains a heat exchange surface comprising 11 000 tubes. The total length of all tubes of one steam generator, exceeds 140 km. The steam generating in steam generators is fed through the secondary circuit steam lines to the turbine where the it’s pressure rotates the steam turbine shaft. The shaft's rotation is passed to the electric generator where mechanical energy is transformed into electricity.
Steam generators are long-cycle production equipment, with the total duration of all production operations, from the start of manufacturing metal workpieces to shipment, of about two years. The production cycle includes welding of separate components into housing, manufacturing of bottoms, drilling of the primary circuit headers, manufacturing and installation of heat-exchanging tubes and internals, as well as a set of inspection activities. Before the shipment from the manufacturer, steam generators are mandatorily subjected to hydraulic and vacuum tests: all process openings are sealed with special plugs, and nitrogen is fed into the unit with pressure. This is a way to confirm the reliability and strength of the equipment that will be used at NPP.