Nuclear power plants in Ukraine

In 2016, we commenced work on the refurbishment of a part of the I&C systems – a unified technology set for the Zaporizhzhya NPP. This delivery includes a software and hardware system for processing input and output signals and their transfer to other control systems of the NPP unit, and a software and hardware automated control system for control of the VVER 1000 reactor CRDM drives. This project was completed in 2019 and commissioned in 2021.

Between 2016 and 2019, ŠKODA JS gradually delivered equipment to prevent the leakage of the core melt from the reactor cavity outside the hermetic containment in the event of a severe accident (LOCA). The device, which will specifically prevent melt leakage through the channels of the ionization chambers, has been delivered to all 13 operating VVER-1000 units in Ukraine. The deliveries contained not only the equipment, preventing melt leakage (plugs containing refractory ceramics), but also special fixtures for mounting the plugs into the channels of the ionization chambers, as well as assembly supervision and operator training. The  customer is NAEK Energoatom, the owner of Ukrainian power plants. The project was part of a comprehensive program to increase the level of safety of the NPP energy units.

Since 2017, we have dealt with another interesting and important project, also aimed at enhancing the safety of power plants in Ukraine – emergency containment depressurization. In the beyond design basis accident, the pressure in the containment would be reduced in a controlled manner through a multi-stage filtration system in order to prevent any radionuclides from escaping into the surrounding area. The project is part of the post-Fukushima measures and its implementation eliminates the risk of overpressurization of the containment, and thus its damaged. This project, in which the main subcontractor for ŠKODA JS is Framatome, is comprised of series of deliveries of equipment, including its assembly. The project involved a total of 11 units of Ukrainian nuclear power plants.

In 2020, the successful acceptance and testing of a special belt conveyor for transporting concrete casks with used fuel took place at the Zaporizhzhya NPP in Ukraine. We delivered the transporter to a long-standing customer – NAEK “Energoatom”. The mentioned transporter is used in the area of ​​the Zaporizhzhya NPP to transport concrete casks between the particular power units and the used fuel interim storage facility.

In the years 2019-2020, we supplied removable upper reserve racks for the storage of spent nuclear fuel at two units of the Rivne NPP.

A modernized refuelling machine was delivered to Units 3, 4 and 5 of the Zaporizhzhya NPP. The project includes the supply and installation of a new control system, including the operating and TV masts of the refuelling machines.

In 2016, we delivered equipment for modification of the main flange sealing of the type HCČ 195M main circulation pumps in VVER-1000 units. The purpose of the modification was to replace the original metal gaskets with a special camprofile gaskets with expanded graphite. The reason for the modification was coolant leakage, caused by damage of the sealing surfaces at the main circulation pumps after long-term operation using hard metal gasket. The newly delivered graphite gasket better eliminates defects on the sealing surfaces and, due to smaller tightening torque, extends the service life of the MCP pumps. The delivery included not only gaskets, but also special machine tools for repairing sealing surfaces, hydraulic stud tensioners and other necessary additions and gauges. This involved not only the delivery of the device itself, but also the transfer of know-how for modification, including pilot assembly supervision during the first implementation and operator training. With the delivered equipment, the NAEK workers are now gradually modifying all MCP pumps at the Ukrainian VVER-1000 units.

Chernobyl NPP

In 2016, the assembly of a cask wagon was completed at the Chernobyl nuclear power plant for the transport of RBMK-type fuel from the nuclear power plant to an interim used fuel storage facility located in an area 30 kilometers away. The contract for supplying a cask of ŠKODA JS’s own design included its design, production, delivery, assembly and certification. The 12-meter-long cask is intended for the transport of 9 special spent fuel assemblies.

Interesting numbers