Study of the Radioactive Silt Sediment Cementation Techniques

Radioactive silt deposits (RSD) of the spent fuel rod cooling pools were used as an object of these studies. In this paper the following techniques were considered for the silt processing: the cementation of silt without a prior treatment, cementation of the dried silt product, cementation of the calcined silt product, and the impregnation of the calcined silt with high penetrating cement grouts. This paper reports the results of the following studies: the chemical and isotope silt composition, physicochemical silt properties, properties of the cement grouts and solidified compounds, obtained as a result of various silt processing techniques. For every processing technique the following cement compound quality index stated in the Russian standard GOST R 51883-2002 was determined: the mechanical strength, freeze-thaw resistance and leach rate of 137Cs. Effects of variations in the thermal silt treatment mode, in the water/cement ratio, and in the binder material type have been determined. Based upon the results of the studies a comparative assessment of the silt cementation techniques has been performed.