THERMAL AND SPECTROSCOPIC ANALYSES OF NEXT GENERATION CAUSTIC SIDE SOLVENT EXTRACTION SOLVENT CONTACTED WITH 3, 8, AND 16 MOLAR NITRIC ACID

Fondeur, F. ; Fink, S.

Savannah River Site (S.C.)

关键词: Removal;    Calorimetry;    Monitoring;    Switches;    Oxidation;   

DOI  :  10.2172/1025909
RP-ID  :  SRNL-STI-2011-00576
RP-ID  :  DE-AC09-08SR22470
RP-ID  :  1025909

美国|英语

来源: UNT Digital Library

【 摘 要 】

A new solvent system referred to as Next Generation Solvent or NGS, has been developed at Oak Ridge National Laboratory for the removal of cesium from alkaline solutions in the Caustic Side Solvent Extraction process. NGS is proposed for deployment at MCU and at the Salt Waste Processing Facility. This work investigated the chemical compatibility between NGS and 16 M, 8 M, and 3 M nitric acid from contact that may occur in handling of analytical samples from MCU or, for 3 M acid, which may occur during contactor cleaning operations at MCU. This work shows that reactions occurred between NGS components and the high molarity nitric acid. In the case of 16 M and 8 M nitric acid, initially organo-nitrate groups are generated and attach to the modifier and that with time oxidation reactions convert the modifier into a tarry substance with gases (NO{sub x} and possibly CO) evolving. Calorimetric analysis of the organonitrate revealed the reaction products are not explosive nor will they deflagrate. NGS exposure to 3 M nitric acid resulted in much slower reaction kinetics and that the generated products were not energetic. We recommended conducting Accelerated Rate calorimetry on the materials generated in the 16 M and 8 M nitric acid test. Also, we recommend continue monitoring of the samples contacting NGS with 3 M nitric acid.