Spontaneous reductive decomposition behavior of permanganic acid depending on initial concentration and reaction temperature for the chemical decontamination of NPP

The spontaneous reductive decomposition characteristics of MnO₄^-have not been studied under chemical decontamination conditions, such as the HP CORD process, using HMnO ₄. In this study, the spontaneous reductive decomposition behavior of HMnO4 was investigated within the range of concentrations and temperatures used in the HP CORD process. The proposed mathematical model consisting of two first-order reactions accurately predicted the spontaneous reductive decomposition behavior of HMnO₄. This behavior was dependent on the residual HMnO₄ concentration and reaction temperature within the experimental error range as follows: X(t,T) = ωe^-k_nt_n + (100 - ω)e^-k_ct_c (3) where k_n = 5.3 x 10^-'5T² - 0.038T + 6.92, k_c = 7 x 10^-6T - 0.0ω = 0.48T - 140, X(%), ω(%), t (min), and T (K). Based on the good fit of the experimental data with the proposed model, k_n and ω accurately simulate the nucleation step, and k_c and 100-ω accurately reproduce the crystal growth step