ŠKODA JS a.s. has recently supplied the EZ 340 tightening unit to the Temelín Nuclear Power Plant

15. 2. 2022

The tightening unit´s modular system enables both tightening / loosening of CRDM housing flange joints and measurement of neutron flux and temperature on the reactor upper block. At the Temelín NPP (VVER 1000/320 reactor) there 91 flange joints to be tightened by this device.

The basis of the EZ 340 tightening unit is a transmission unit with tightening drives. An integrated control box is attached to the top of the transmission unit. A guiding column and two sets of tightening rods (per 6), enabling tightening of bolts and push-out screws, are connected to the lower part of the transmission unit. The height of the device is almost 5.4 metres, the weight of the device is 570 kg. The tightening unit is moved between the individual connections by means of a crane.

The EZ 340 tightening unit significantly simplifies tightening and loosening of flange joints and thus shortens the length of power plant downtime. The equipment is operated by two workers. In addition to shortening the time required, the use of the device significantly increases the accuracy and uniformity of tightening the flange joints. Together with the integrated recording, the delivered device will have a positive impact on reduced wear and longer service life of the flange joints.

EZ 340 represents the next development stage of tightening devices, the rate of digitization and the use of computer technologies is higher. Touch screen controls the movements of the actuators and analog and digital modules, which measure all the necessary quantities. All data relating to the entered parameters, system configuration or the current cycle / service phases are displayed on the PC screen.

Through the development and production of this tightening unit, ŠKODA JS has once again demonstrated its qualifications and ability to monitor technical developments and apply the latest knowledge, methods and experience from nuclear power plants to the equipment offered to its customers. The EZ 340 tightening unit was created within the cooperation of teams across the entire company and in cooperation with ČEZ a.s.