Overview of R and D Support of PWR Steam Generators

Abstract

From the sixties, intensive researches on steam generator materials behavior have been carried out and amplified when the first specific problems occurred on operating power plant in the early seventies. These researches allowed considerable improvements on the knowledge of various materials behaviour to stress corrosion cracking in aqueous environments more or less contaminated. They also permitted to determine with much more precision, the concentration mechanisms in areas under thermal flux with restricted flow, to improve the calculations of residual stresses (either manufacturing stresses or implementation stresses) on tubes, and finally to progress on thermohydraulics knowledge. All these researches allowed to find remedies to encountered problems, with the selection of new materials, adequate chemical guidelines, implementation of new technics for lowering the stresses, and improvement of thermohydraulic design for minimizing corrosion, fatigue or wear risks.