[en] The steady stress, modal analysis for the damaged blade was carried out to evaluate the integrity of LP 4 blade row. As a result, 4 dangerous modes for LP blade row were found in the interference diagram and it was confirmed that the nozzle passing frequency has nothing to do with the blade failure. And then the dynamic stress are analysed for the 4 dangerous modes. There are some points far out of maximum allowable stress in the cover and tenon. Therefore the blade is not safe according to the Goodman judgement. So the manufacturer have modified the design of cover and tenon. Until now, the power lant is being operated without special problems

[en] Amount of electricity which product generator decide control valve at turbine. Operating method of control valve have two mode. First operating method is partial arc admission, and second operating method is full arc admission. Failure of control valve have on serious damage electricity lineage. In this paper, We have investigated resonance that control valve spring casing