As an RCP(Reactor Coolant Pump) run in the nuclear power system for a long time, it's surface is continuously contaminated by radioactive scales. In order to perform regular or emergency repair about RCP internals, a special decontamination process should be used to reduce the radiation from the RCP surface by means of chemical cleaning.
From commercialization of nuclear power, most countries have taken interest in decontamination process of nuclear power plant and tried to develop a proper process. As result of that, nowdays, some countries have their own decontamination process and don't want open their technology to the pubic. Because that, it is impossible to obtain skills about decontamination of foreign country and it is necessarily to develop proper decontamination process system in korea. So, on the base of skills about decontamination of foreign country which was already opened in pubic KPS and our institute has developed two kinds of decontamination process itself. One is KK(KEPCO ＆ KPS) process which is a kind of concentrated chemical decontamination process, the other is KKD(KEPCO ＆ KPS Dilute) process which is a kind of dilute chemical decontamination process.
In general, the RCP internals are made of 304 stainless steel which can cause a corrosion damage, such as intergranular corrosion or pitting corrosion, during decontamination process. Because of that, we carried out various experiments about corrosion damage on 304 stainless steel. In order to conform the proposed process(KK and KKD process), corrosion characteristics of stainless steel(RCP matrial) have been studied by means of polarization test, weight loss measurements, scanning electron microscope(SEM) investigation and pH and potencial(mV) investigation in KK and KKD process.