Adopting methods

such as macroscopic inspection

chemical analysis

metallographic examination

energy spectrum analysis

and fracture scanning etc.

the causes leading to bearing pedestal falure of the valve concerning seaweter pump of unit no. 5 have been analysed. It is believed that the main cause to be intercrystalline brittle fracture resulted from crevice corrosion. For this reason

some measures have been put forward

namely using non - hygroscopic gaskets or fillers; edges of the bearing pedestal to be sprayed with corrosion resistant coating or brushed with anticorrosive paint; changing designed structure to advoid crevice and stagnated regian

etc.