Koroze slitin zirkonia v prost?edi vyssich koncentraci lithia/ Corrosion of zirconium alloys in the environments with elevated concentration of lithium

A series of long-term in-situ experiments studied the negative impact of lithium ions on two types of zirconium-niobium alloys Zr1Nb. Behaviour of the alloys was monitored by in-situ applied electrochemical methods in an experimental high-pressure and high-temperature circuit (280 °C, 8 MPa) enabling media circulation. The experiments were executed in the environment that simulates standard composition of a coolant in both a water reactor and environments with elevated concentrations of lithium (70 and 200 mg l[-1] Li[+] in a form of LiOH). In both exposure environments, the goal of the experiments was to monitor transport parameters of the oxidic layer, changes in the corrosion rate, diffusion parameters and the oxide semi-conductive character. The results implied that the corrosion rate increases after 200 hours of exposure to environments with elevated concentration of lithium. Lithium ions substantially affect the density of dopants, i.e. the semi-conductive behaviour of the zirconium oxidic layer.