Activity: Examination types › Supervisor or co-supervisor of doctoral thesis
Retention processes of redox sensitive radionuclides in crystalline rock Nuclear energy could play important and irreplaceable roles in alleviating the risk of global climate change and energy crisis, but its safety problem has drawn more public attention after Fukushiama nuclear power plant accident. The research on the safety of whole nuclear fuel cycle should be reinforced so as to reconcile those concerns and ensure the sustainable development of nuclear energy. The disposal of nuclear waste, especially high-level radioactive waste, like the safety of the nuclear reactor operation, plays an important role in nuclear safety. At present, a relatively complete nuclear industrial system has been formed in many countries. However, with the rapid development of nuclear energy, there is an increasing amount of accumulated radioactive wastes which are not timely disposed, causing highlighted safety, social and environmental problems. If not handled properly, the sustainable development of nuclear energy would be hindered. This work is to deal with some chemical processes affecting the mobility of the redox sensitive elements namely Se and redox stable elements Ra in deep granite fracture- groundwater systems. The major efforts of this work is to be focused on the following aspects: (1) The natural distribution of trace elements in heterogeneous fracture filling material; (2) The correlation between different redox sensitive elements and iron contents of the mineral aggregates in fracture systems of crystalline rock; (3) Sorption processes of redox sensitive elements, with respect to: (a) influence of clay contents and particle size; (b) sorption reversibility, as measured by sorption/ desorption isotherms, pH dependence and isotopic exchangeability; (4) Synthesis and characterisation of carbonate green rust (GRNa,CO3); (5) Reactions between carbonate green rust (GRNa,CO3) and redox sensitive elements.