Producing or, more precisely, printing metal parts weighing up to 600 kilograms. ČEZ is already using 3D printing technology in cooperation with ŠKODA JS for this purpose. Until now, companies have focused mainly on printing plastics or smaller metal parts. However, both the coronavirus crisis and the war in Ukraine partially disrupted supply chains and energy companies were forced to react in some cases “on their own” in order to keep outage times as short as possible. In a few weeks, they were able to put new parts into machinery to replace defective components, which would have been waiting for months if standard production were relied on.
"This is another step related, among other things, to strengthening our independence in the supply of spare parts and the planned operation of nuclear units for at least 60 years. Thanks to 3D technology, we are able to produce new, completely identical parts, which is important in the event that a supplier no longer exists or does not produce the part,” explained Bohdan Zronek, a member of the ČEZ Board of Directors and Director of the Nuclear Power Division.
ŠKODA JS experts use three different technologies for 3D printing. They all work with different forms of fused material, but the means used for shaping differ. “The choice of 3D printing technology depends on the material and requirements for a part. Then, using 3D scanning, we prepare the data and can start printing. We can produce simpler parts within a few hours,” said František Krček, CEO of ŠKODA JS.
According to experts, 3D printers are a suitable complement to classic CNC machines. “For example, it is still better and cheaper to produce a shaft using machine tools. For very complex parts, such as a gear wheel for a gearbox, it is better to use 3D technology,” added Krček.
Currently, ČEZ is using metal parts produced using 3D technology mainly in the non-nuclear part of the plant, where the equipment has a lower level of qualification. Even so, the power engineers test the finished parts in the material control laboratory at the Training and Implementation Centre before deployment. In the future, ŠKODA JS would like to extend the supply of 3D parts to nuclear operations as well.
In addition to nuclear power plants, 3D printing has already been used at ČEZ hydroelectric power plants. At the turn of the year, for example, it helped to quickly deliver a key component for one of the turbines at the Dlouhé stráně pumped storage power plant, a key regulating source in the Czech power system.
The impeller on the oil pump for cooling the suspension bearing of the second unit of the largest Czech pumped storage power plant went out of service overnight and had to be quickly replaced. However, power engineers would normally wait about 3.5 months for the 165 x 82 mm, 3.2 kg part to be delivered.
“With comparable production costs, the pump at Dlouhé stráně was back in operation in just 14 days. This is thanks to good cooperation across the ČEZ Group and innovative processes, led by modelling with the help of 3D laser scanning and tool steel production through metal 3D printing. Due to the importance of Dlouhé stráně, which is capable of supplying hundreds of MW of regulating power to the Czech power grid for several hours if needed, every day played a role in this case,” said Róbert Heczko, Director of Hydroelectric Power Plants at ČEZ.
Marek Sviták, Martin Schreier, ČEZ Group Spokesmen