From the first putting into operation, this turbine had problems with leakage of the split plane of the turbine casing. In the course of operation it also came to breakaway of a part of the blading shroud. Then there were also damaged blades of the nozzle segment, strips of the steam glands and it was detected a crack of the weld in the vertical split plane.

It was performed indication of planeness of the split plane, due to which it came to equalizing of this plane by means of milling. Consequently it was necessary to make round-off of all functional surfaces of the casing. It was elaborated a strength analysis of the turbine casing. On the basis of the result of this analysis there were realized adaptations in the split plane with a view to improve distribution of the contact pressure and so to improve tightness of the split plane. It was adapted location of some holes for screws and bigger screws were applied at the critical points. Due to such adaptations it came to considerable improvement of tightness of this split plane.

As a problem it emerged breakaway of the shroud. Since whole impeller is made of single piece and of material unsuitable for welding, it was decided on complete removal of the blading shroud. For check of vibrations of the wheel it was elaborated a modal analysis. From its results it emerged that dynamic properties of the rotor are complying and the critical speed is situated sufficiently far from the operating speed. The deviations are minimal and rotor stability is sufficient for safe operation.