Some specific features of organic waste combustion in fluidized bed facility

Discussion is given to the specific features of reprocessing nuclear fuel cycle liquid organic waste in a fluidized bed apparatus at moderate temperatures. Issues are considered relevant to efficiency and safety of the process and effects of nitrogen oxides on temperature regime. Conditions of thermal decomposition of TBP, paraffin and aromatic hydrocarbons (Dowtherm) are revealed. Relations are established of interactions between phosphorus oxides resulting from TBP combustion and a packing material (Al, Ca). Cs and Ru trapping efficiency is evaluated for organic phase combustion on bed granules. The recent studies have shown that hydrocarbon compounds available in waste to be disposed of can promote transuranium nuclide migration and subsequent escape to the environment. This is the reason why reprocessing this type of nuclear fuel cycle waste is one of the most important directions in waste localization. Investigations carried out in the course of the liquid nitric acid waste calcination in a fluidized bed apparatus indicated the high efficiency of kerosene thermal oxidation within 400--500 C. In this connection the authors have performed experiments in a laboratory scale to more accurately determine combustion regime for some organic compounds that found use in technologies of spent fuel radiochemical reprocessing. The studies were conducted in a fluidized bed facility. Its major component is a packed apparatus in the form cylinders with a cone shaped joint in the middle