Safety confirmation study of TRUEX solvent by accelerating rate caorimeter (ARC)

Sato, Yoshihiko; not registered; not registered; not registered; not registered

In order to confirm the engineering safety on the TRUEX solvent (mixed solvent of CMPO/TBP/n-dodecane) for separating the transuranics from high-level activity liquid waste in advanced nuclear fuel recycling technological R&D, thermal behavior and pressure behavior in heating PUREX solvent (mixed solvent of 30% TBP-n-dodecane), TRUEX solvent and in the exothermic reaction of TRUEX solvent etc. and nitric acid in sealed adiabatic system which was severer condition than actual plant were measured by using accelerating rate calorimeter (ARC). The Arrhenius parameters (activation energy and frequency factor) which are necessary for the evaluation of reaction rate was examined from the measurement data in ARC. Analytical method and analysis condition of reaction products were examined in order to clarify chemical form of reaction products in exothermic reaction between solvent and nitric acid in ARC, and the qualitative evaluation was carried out. Main results are shown in the following. (1)TBP, CMPO, n-dodecane and 10M nitric acid hardly exothermed in the simple substance. (2)On the solvent phase after the solvent contacted 10M nitric acid and chose equilibrious (single phase system sample), it tended to be bigger the heat quantity per unit sample weight of the TRUEX solvent than the PUREX solvent when heat quantity was evaluated in ARC. However, on the sample enclosed solvent and 10M nitric acid in sample container simultaneously (two phase system sample), the heat quantity per unit solvent weight was almost equivalent for PUREX solvent and TRUEX solvent. (3)The kinetic analysis was carried out, and on the TBP-10M nitric acid single phase system sample, the activation energy of the reaction was evaluated with 118kJ/mol. Its activation energy was approximate to 112kJ/mol by Nichols. Reaction rate canstant was calculated, and it was shown that reaction rate constant of PUREX solvent-10M nitric acid single phase system sample and TRUEX solvent-10M nitric acid ...