The effect of the addition of Alumina powder on the confinement properties of a cement mortar

Organic radioactive waste can occur in solid, liquid or rarely gaseous form. In general, organic components of radioactive waste Generally, the organic components of the radioactive waste have a contaminant effect stronger than most of the inorganic components, because of their low melting point, of their answer to the radiolyse or of their volatilitydu to their low melting point, to their answer to the radiolyse or to their volatility. This property can significantly affect the strategy adopted for their management. Organic radioactive waste results from the use of radioisotopes in the National Center for Energy, Nuclear Science and Technology (CNESTEN) and from medical applications. Organic radioactive waste requires management steps that take into account not only their radioactivity but also their chemical content. The aim of this study is the optimization of the stabilization of radioactive organic effluents in cementitious matrices. Thus, we study the effects of the addition of the alumina powder on the physicochemical and mechanical properties of the cement paste. The mortar was made by mixing Portland cement, sand, water and alumina powder (88 μm). The study showed that the addition of 12% alumina powder improves the compressive strength.

Treatment of Spent Solutions Containing Tributilphosphate

The realization of the process of treatment of organic radioactive waste (RW) containing tributilphosphate (TBP) in hydrocarbon solvent under the laboratory conditions is considered in this work. The main parameters of the process have been investigated as well as the characteristics of the final process product — sodium-aluminiumphosphate glass matrix.

Solidification of 30% TBP-OK Waste by Calcium Sulfoaluminate Cement

Liquid organic radioactive waste is one kind of wastes from the use of radioisotopes in research centres, medical and industrial applications and also in nuclear power plants. Effective management of these liquid organic wastes is necessary in order to ensure their safe handling, processing, storage and disposal. Cementation for Tri-N-Butyl Phosphate/Odorless Kerosene (TBP/OK) solvents was studied. Emulsifiers were selected and compared. Calcium sulfoaluminate cement (SAC) was used in TBP/OK solidification. A prescription containing 20% (v/v) TBP/OK was obtained. And the compressive stretch is above 10MPa. The leach rates of Sr2+, Cs+, Co2+ were studied. Monolithic solids were formed.

Oxidation of Organic Radioactive Waste by Electrochemical Mediation

Liquid as well as solid organic radioactive waste can be processed by means of combustion. However, this method presents several well-known drawbacks including the corrosion of the ovens, the production of radioactive ashes and radioactive or toxic volatile products. The electrochemical mediation process is an excellent alternative to combustion, especially when dealing with hazardous materials such as explosives, pesticides, drugs and nuclear organic waste. Nevertheless, using the silver(II) species as electrogenerated mediator, requires to work in concentrated nitric acid media, which results, via its electrolysis, in a continuous NOx emission. The classical approach, using absorption columns and scrubbers to trap NOx, impairs the attractiveness of this process. Therefore the SCK•CEN has developed and patented an original method to suppress in-situ any formation of NOx, conferring the process mobility and compactness.