In 2018, yellow, hitherto unknown, deposits were discovered on hot plant components during a turbine inspection. Laboratory analyses revealed that these deposits were the carcinogenic “chromium VI” according to the Ordinance on Hazardous Substances (GefStoffV). The exact mechanisms of formation of these deposits have not yet been settled. It can be assumed that this problem has existed since the use of chromium steels in power plant construction, but was not noticed for a long time. However, it is considered certain that chromium VI forms at temperatures > 150 °C. When this topic became known to vgbe, two working groups were immediately set up in 2019:
The 1st group deals with problems related to mechanical processing, i.e. grinding, welding, cutting, i.e. processes that cause high temperatures.
The 2nd group deals with issues related to chromium VI deposits on hot parts, which lead to considerable problems and additional costs (safety measures), e.g. in the context of inspections.
The exchange of experience on this topic is constantly going on. In addition, a vgbe Standard is being developed to provide operators with a working basis for designing their inspections. In the meantime, such inspection concepts are also demanded by some authorities in connection with chromium VI. The next meeting of the working group will take place on September 13, 2023. If you are interested in participating, please contact Andreas Böser ( andreas.boeser@vgbe.energy ).
The issue of chromium VI will also be presented and discussed at the vgbe Conference “Occupational Health and Safety in Power Generation 2023” 21. taking place in Hagen on November 21 – 22, 2023.
