Grant: Alliance Grants

Through the NSERC Industrial Research Chair program, the University of Guelph has developed a world-class laboratory for high-temperature aqueous chemistry, equipped with custom-made, state-of-the-art, high-precision spectroscopic and thermochemical instruments to study the properties of aqueous solutions at the extreme conditions used in Canada's nuclear industry. The proposed research seeks to use this expertise to identify key chemical reactions and measure the thermochemical parameters needed for the development of internationally accepted databases for modelling and chemistry-control of new or refurbished CANDU Pressurized Heavy Water nuclear reactors and proposed Small Modular Reactors (SMRs); and for evaluating/licencing sites for the geological storage of nuclear spent fuel. The program consists of five projects. (i) A definitive laboratory study to provide quantitative data and predictive tools to model the deuterium isotope effects on metal oxide solubilities under CANDU D2O primary coolant conditions will be completed. (ii) Calorimetric and spectroscopic studies will determine the properties of newly proposed organic additives for redox and pH control in steam generator circuits up to 325 C. (iii) Pressure vessel and Raman spectroscopic studies will measure thermodynamic properties needed to predict the onset of corrosive transition metal "hideout" reactions in secondary coolant circuits (250 - 325 C), at concentrations up to their solubility limits. (iv) "Hideout" reactions and critical locus effects in primary and secondary coolant circuits of water-based SMR reactors, including supercritical steam generators (> 373 C) will be examined. (v) Experiments to measure formation constants for the aqueous UO2(2+) and lanthanide Ln(3+) complexes will be completed and, in Year 3, experiments will begin on Th(4+) systems. These are surrogates for NpO2(2+), Cm(3+) and U(4+), which are difficult to study because of high radioactivity or extremely low solubilities. Our partners are the University Network of Excellence in Nuclear Engineering, CANDU Owners Group, the Nuclear Waste Management Organization and the Electric Power Research Institute.