Extractants such as tri n-butyl phosphate form an explosive composition called as red oil in the presence of nitric acid under high temperatures. The formation and subsequent decomposition of red oil can lead to explosive thermal runaway conditions and is therefore, a safety concern during the spent fuel reprocessing and waste management operations. A review of the literature on the red oil excursions and related safety issues has been carried out covering the major accidents that have taken place and the literature on the red oil related studies. Other extractant systems which are also likely to undergo red oil like excursions are also covered.

Red Oil Excursions: A Review

Autocatalytic decomposition of tributyl phosphate in the spent extractant of the PUREX process for safe disposal of radioactive impurities

Thermochemical interaction of TBP with nitric acid in single-phase organic systems has been studied at the concentrations of HNO3 1.4 to 5.6M, in temperature range of 110–140 °C. The termochemical oxidation of TBP includes a number of consecutive and concurrent reactions, such as acid hydrolysis, the oxidation of the TBP hydrolysis products, and TBP destructive oxidation. Some of these reactions can proceed with heat explosion. The limiting temperature (120–130 °C) and acid concentration (2.5 mol/l) at which the oxidation reactions are able to transform to heat explosion have been estimated. The rate constants and activation energies were determined for the reactions presenting a potential hazard.

Chemical oxidation of the components of extraction solutions and critical parameters of heat explosion. i. kinetics of the interaction between tbp and nitric acid

E. R. Nazin

Papers

Chemical oxidation of the components of extraction solutions and critical parameters of heat explosion. i. kinetics of the interaction between tbp and nitric acid