April 6, 2021, Büyükeceli, Mersin province, Turkey - On March 20, 2021 the first heavy component of the steam turbine set – the rotor of the high and intermediate pressure cylinder (HP and IP cylinder), which weighs above 107 tons and is more than 12 meters long – was delivered to the Akkuyu NPP construction site.
The use of a combined HP and IP cylinder is a unique feature of Arabelle steam turbines to be installed at all four Akkuyu NPP power units. Such design enables to achieve the maximum possible turbine hall efficiency factor – up to 38%. This is the record high value of the NPP turbine set efficiency factor in the global nuclear power industry.
The NPP turbine set represents a high-efficiency rotary thermal engine. The cylinder rotor is one of the key components of such engine: the high-pressure steam flow produced by the reactor hall steam generators is supplied to the rotor blades. The potential energy of the compressed and heated water steam causes the rotor spinning and thus is converted to the mechanical energy, which is supplied to the turbine generator producing the electric current.
The HP and IP cylinder rotor was manufactured at the GE Steam Power factory (branch of US-based General Electric) in the town of Belfort (France). It took about 16 months to produce the rotor after obtaining a manufacture approval from the Nuclear Regulatory Authority (NDK). In January 2021, the representatives of the equipment supplier, AAEM LLC (a joint venture of Atomenergomash JSC and GE Steam Power), and AKKUYU NUCLEAR JSC carried out the acceptance of the equipment at the manufacturer's facilities and thus confirmed compliance with the production technologies according to the high quality standards. After acceptance the HP and IP cylinder rotor was stored at the factory for 2 months, and was then shipped and delivered by sea to the Akkuyu NPP construction site.
“The delivery of the cylinder rotor for the Arabelle steam turbine to the Akkuyu NPP construction site is an event that clearly demonstrates the wide international reach of our project, not limited to Russia and Turkey. The main equipment of the steam turbine unit is manufactured by a branch of the US company in France. The list of manufacturers, equipment suppliers and project participants in general includes companies from many countries. Orders for the manufacture of pumping, heat exchange, electrical and other auxiliary equipment have been placed in Hungary, Czech Republic, Italy, Spain, Poland, and Japan. Independent technical control of construction work at the site is carried out by the international engineering group Assystem, which operates in 17 countries of Europe, the Middle East and Asia,” said Sergei Butсkikh, AKKUYU NUCLEAR JSC First Deputy General Director - Director of Akkuyu NPP under construction.
As of today, the Arabelle half-speed steam turbine is the best-in-class turbine set among those available on the market, in terms of power: the turbine power can reach 1900 MW, with the welded design of rotors ensuring high corrosion-resistance, long service life of the key components (at least sixty years) and extended maintenance intervals.
The joint venture AAEM LLC was established in 2007 for furnishing the turbine halls of Russian-design NPPs using the GE Arabelle steam turbine technology. Since 2017, AAEM LLC has been implementing the project on delivery of equipment of a complete turbine hall steam turbine set for the Akkuyu nuclear power plant. The operation on unloading the rotor – from lifting it out of the ship's hold to the delivery to a warehouse in the area of the Eastern construction base – took 6.5 hours. The heavy cargo was transferred with vessel cranes onto a special wheeled platform, which brought the HP and IP cylinder rotor to a sheltered storage area.