Applicability of a Model Predicting Iodine-129 Profile in a Silver Nitrate Silica-Gel Column for Dissolver Off-Gas Treatment of Fuel Reprocessing

Abstract

The applicability of a mathematical model predicting iodine-129 profile in a silver nitrate silica-gel (hereinafter referred to as Ag-S) column for radioactive iodine treatment was examined using actual off-gas from a dissolution step of a spent nuclear fuel reprocessing test rig, where PWR spent fuels with burnups up to 44,000 MWdt 21 were dissolved. The iodine-129 profile predicted by the model showed good agreement with the iodine profile obtained in the experiment. It was suggested that the model would be useful to predict iodine profiles in an Ag-S column operated at 423 K for the off-gas treatment of actual spent fuel dissolution. Also, the values of the parameters used in the prediction, i.e., the effective diffusion coefficient and the Langmuir coefficient, were supposed to be applicable within the volumetric NO 2 concentration range lower than 1%.

Adsorption of iodine on hydrogen‐reduced silver‐exchanged mordenite: Experiments and modeling

“…Radioactive iodine ( 129 I) is one of the major volatile radionuclides released in the off‐gas streams of spent nuclear fuel reprocessing facilities . The adverse impact on human health of the radioactivity and long half‐life (15.7 million years) make the removal and immobilization of gaseous 129 I crucial.…”

Van de Graaff Experiments: Mo Redox Chemistry and Iodine Speciation

“…Molecular iodine, I 2 , is nonpolar and can be extracted into a nonpolar organic solvent such as chloroform or toluene (Cripps et al 2003;Mineo et al 2003;Kahn and Kleinberg 1977;Kahn and Wahl 1953;Evans and Jervis 1992).…”

“…In this work, determination of iodine speciation in Van de Graaff-irradiated solutions was performed by utilizing solvent extraction techniques and differences in the chemical behavior of iodine species (Cripps et al 2008;Mineo et al 2003;Kahn and Kleinberg 1977;Kahn and Wahl 1953;Evans and Jervis 1992): 1. Molecular iodine, I 2 , is nonpolar and can be extracted into a nonpolar organic solvent such as chloroform or toluene (Cripps et al 2003;Mineo et al 2003;Kahn and Kleinberg 1977;Kahn and Wahl 1953;Evans and Jervis 1992).…”

Capture of harmful radioactive contaminants from off-gas stream using porous solid sorbents for clean environment – A review

“…reported the silver-impregnated silica-gel (AgS) sorbent was used to trap 129 I in cartridge filters [46]. Mineo et al [47,48] developed a mathematical model for the removal of 129 I from the dissolver off-gas treatment on silver nitratesilica gel packed bed. Gaseous iodine was removed using silver-impregnated alumina (Ag/Al 2 O 3 ) at different temperatures (373 -923 K); the sorbent was active at high temperatures during nuclear accident [49].…”