Partitioning of heat generating fission product (Cs-137 & Sr-90) from acidic medium by 1,3-dioctyloxy-calix[4]arenecrown-6 (CC6) & Octabenzyloxyoctakis[[[(N,N-diethylamino)carbonyl)]methyl]oxy]calix [8]arene (BOC8A) in nitro octane diluent: Batch scale study & process parameter optimization

摘要

Partitioning of heat emitting fission product 137Cs & 90Sr in a single solvent extraction step with nearly zero actinide and lanthanide contamination have been studied using a mixture of calixarene based ionophore 1,3-dioctyloxy-calix[4]arenecrown-6 (CC6) & Octabenzyloxyoctakis[[[(N,N-diethylamino)carbonyl)]methyl]oxy]calix [8]arene (BOC8A) in a nitro alkane based diluent nitro octane (NO). A mixture of 0.03 M CC6 and 0.01 M BOC8A in NO showed high selectivity (separation factor greater than 100) towards Cs (Dcs = 4.0) & Sr (DSr = 4.6) with respect to almost all other element except Na (DNa = 0.9), Ba (DBa = 1.48) and Pu (IV) (DPu = 0.4) present in the simulated high level liquid waste (SHLLW). Role of different parameters effecting distribution of Cs & Sr such as equilibration time, feed acidity, extractant concentration, and temperature were evaluated to optimize the condition of extraction and stripping of Cs & Sr. Extraction of Cs & Sr was found to be exothermic in nature. The outcome of this work gives an insight into amenability of co-decontamination of heat generating fission products from high level waste (HLLW) using mixture of BOC8A & CC6 in NO diluent.