Thermochemical Stability of Extraction Systems for SNF Processing

Thermal stability of extraction systems containing N,N,N′,N ′-tetra-n-octyldiglycolamide (TODGA), di(N-ethyl-4-hexylanilide) 2,2′-bipyridine-6,6′-dicarboxylic acid (DYP-7), di(N-ethyl-4-fluoroanilide) of 2,6-pyridinecarboxylic acid Et(pFPh)DPA, di(N -ethyl-4-ethylanilide) of 2,2′-bipyridine-6,6′-dicarboxylic acid (DYP-9) under the conditions capable of causing emergencies, i.e., those unfavorable as regards the fire and explosion safety. It was found that irradiation with accelerated electrons of a TODGA–Isopar-М mixture in an n-alcohol affects the possibility of a thermal explosion and shown that the irradiation is accompanied by an intense evolution of gases. The possibility of passing from the oxidation of organic components of the system by nitric acid to the burning and explosion mode was evaluated. It was found that, with diamides used, the pressures of gaseous products of exothermic reactions are substantially lower than those with TODGA and TBP, which makes them promising extracting mixtures as regards the safety of the technological process.