Highly improved radioiodine vapor capture by the non-decarbonized Bi/La-C-oxide and the post-sorption waste consolidation through addition of ZnO

In this work, a novel inorganic-organic Bi/La-C-oxide material for iodine vapor capture in conditions of high temperature, mostly encountered during the reprocessing of the spent nuclear fuel, was synthesized. Bi/La-C-oxide (Bi/La=1, 300 °C) was synthesized using a new approach that allowed the non-decarbonization of used fuels, which instead made a framework with the core of Bi/La oxide to form a hybrid material, which exhibited a fast iodine uptake with a capacity of 1339.64 mg·g −1 at 18 h and 1301.47 mg·g −1 after 26 h at 200 °C, respectively. Notably, Bi/La-C-oxide (Bi/La=1, 300 °C) owed the high iodine-adsorbing ability mainly from its structure made of tetragonal units of Bi 1.92 La 0.08 O 3 linked together with esters to form a polyesterified Bi/La-C-oxide framework. The thermal stability analysis of the materials before and after iodine capture showed high thermal stabilities, proving their ability to withstand real-field high-temperature conditions. ZnO was used to consolidate the iodine wastes to avoid post-sorption secondary pollution, and the iodine leaching rate was minimized to 1.143 × 10 −3 g·(m 2 ·day) −1 after 7 days of product consistency test-A.