Work is underway to install the first turbine at unit 1 of Russia’s Kursk-II NPP. Placing a turbine unit on a rotating device (VPU – ValoPovorotnoe Ustroistvo) is one of the key operations during the commissioning period, which demonstrates the high technical readiness of the turbine unit and its auxiliary systems for testing during the cold and hot testing of the reactor plant. This was preceded by a large complex of work related to the installation of all turbine elements, alignment of the shaft line, inspection and testing.
“Putting the turbine unit on the VPU is the final point in the installation of the turbine and generator, after which the turbine unit will no longer be opened until the first scheduled repair,” said Kursk NPP Plant Director Alexander Uvakin. “The next key event in the unit 1 turbine room will be a vacuum test set, which is scheduled for mid-July. We are now conducting full-scale preparations for this operation, which involves a number of facilities of the start-up complex and various services of the station. This work must be completed before the physical start-up.”
The VPU is driven by a 30 kW electric motor. At the time of commissioning, the task of cranking the turbogenerator from the VPU is to check the correct assembly of the turbine, evaluate the alignment of all elements and the readiness of various systems for start-up. According to the technical requirements, during installation the tolerance for divergence in the turbine axes is no more than 0.03 mm.
“During the rotation of the turbine, no defects were detected – this indicates a high level of assembly and careful joining of all its elements,” said Oleg Shperle, Vice President of Atomstroyexport JSC and Project Director for the construction of Kursk-II. “The shaft turning device is an important equipment of a turbine unit. It is mounted on a cover of two bearings. The VPU ensures rotation of the rotors at a frequency of 1.05 rpm for their uniform heating during startup and cooling when the turbine is stopped. This prevents the rotors from bending during operation. During industrial operation of the first power unit of Kursk-II, the rotation speed of the turbine unit blades will be 1,500 rpm. Completion of this stage is another step to ensure the timely physical start-up of the power unit.”
Kursk II will replace the currently operating Kursk NPP, which comprises four ageing RBMK reactors (one of which is already closed). Units 1&2, currently under construction, will have VVER-TOI reactors – a development of the VVER-1200 reactor design. The VVER-TOI has increased power and improved technical and economic indicators, as well as increased resistance to extreme external influences.
