Analytical investigation of multi-dimensional hydraulic characteristics at plug region of higher-pressure turbine outlet piping for ATR FUGEN

not registered; Sugawara, Satoru

A small steam leakage was discovered at a plug region of the higher-pressure turbine outlet piping of the FUGEN reactor on october 18, 1992. It was concluded that the cause of the leakage is due to the erosion process by wetted steam flows from the higher-pressure turbine outlet piping. In this study, multi-dimensional hydraulic characteristics at the plug region have been investigated using a multi-purpose thermohydraulics analysis code AQUA. From the analysis, the following results have been obtained: (1)Decreasing of maximum velocity components in the plug was 84 % in the case that a mean steam velocity in the higher-pressure turbine outlet piping decreases to 31.3 m/s (75.8 %) from 41.3 m/s. (2)Maximum velocity components in an improved plug was reduced to 0.44 % compared with the original plug condition. It was concluded that the improved plug can be prevent effectively the growth of the erosion process.