Research and Analysis of Optimization of Program for SG Wet Layup during Shutdown in Nuclear Power Plants
In order to mitigate corrosion of internal materials during outage and subsequent power operation,steam generator(SG)is put into dry or wet layup.During wet layup,the pH,hydrazine and the corrosive impurity are the mainly controlled.Large numbers of tests and studies on effect of wet layup conditions,such as pH and hydrazine,on materials corrosion were carried out in foreign plants and institutions.However,at present,there are few systematic researches on wet layup specification in domestic plants.The rules of specification definition are different and the specification requirements are different and not specific for SG wet layup.Therefore,it is not conducive to implement and cause higher hydrazine concentration or lower pH.In this paper,corrosion test of materials was analyzed and it is concluded that wet layup under N2 blanket,pH＞10 or N2H4＞75 mg/kg are all helpful for mitigating the corrosion of carbon steel.Then,optimization of wet layup strategy was proposed accordingly with considering plant conditions.It could provide support for plants to optimize SG wet layup strategy.
NETL
NSTL
万方数据
