논문 상세보기
Behaviors of Metals During the Cyclic SP-HyBRID Process of Reactor Coolant System in a Pressurized Water Reactor
- 언어ENG
- URLhttps://db.koreascholar.com/Article/Detail/430597
p.301
Activated corrosion products deposited on the reactor coolant system in a nuclear power plant should be removed to reduce the radiation exposure to workers. Chemical decontamination processes using organic acids have been widely applied to remove the activated corrosion products. However, they are highly corrosive to the base metal and generate a considerable amount of ion exchange resin waste, which is hard to be treated. In order to resolve this problem, KAERI has been developed a chemical decontamination process using chelate-free inorganic acid, HyBRID (Hydrazine Based Reductive metal Ion Decontamination) process. Especially, the Cyclic SP (Sulfuric acid/Permanganate)- HyBRID process was suggested as the decontamination process for applying to the remove the double oxide layer generated on the reactor coolant system in the pressurized water reactor (PWR). During the Cyclic SP-HyBRID process, the process is continuously applied without discharging or recharging of the decontamination process solution from the primary circuit. Thus, it is necessary to include the removal processes of the decontamination reagents middle of the Cyclic SP-HyBRID process, e.g., ‘Mn removal step’ for removing the permanganate ions and ‘hydrazine decomposition step’ for decomposition of the remaining hydrazine. During these removal processes, the metal ions can also be removed from the process solution. In this study, the behaviors of metals were investigated during the Cyclic SP-HyBRID process. The concentration changes of metal ions in the process solution were analyzed using atomic absorption (AA) spectroscopy. The metal precipitates generated during the process were characterized using X-ray diffraction (XRD) and Fourier Transform Infrared (FT-IR) spectroscopy. From the results of the analysis, it was observed that the metal ions dissolved in the process solution were converted into metal hydroxides and precipitated at the Mn removal process. It was confirmed by equilibrium calculation result that the OH− ions generated at the Mn removal can react with the metal ions and form the metal hydroxides. It is considered that this removal behaviors of the metals can contribute the decontamination performance.
