Unravelling the potential of iodine isotopic exchange in CH3131I capture by K127I-impregnated activated carbons

IF 2.8 2区工程技术 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Nuclear Materials Pub Date : 2025-03-01 DOI:10.1016/j.jnucmat.2025.155719

K. Abbas , M. Chebbi , B. Azambre , C. Monsanglant-Louvet , B. Marcillaud , A. Roynette

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引用次数: 0

Abstract

The efficient capture of radioactive methyl iodide (CH₃¹³¹I) is a critical issue for nuclear safety and radioprotection. Co-impregnated activated carbons (AC), with triethylenediamine (TEDA) and potassium iodide (K¹²⁷I), are widely employed for this purpose. However, the specific role of KI in CH₃¹³¹I retention through isotopic exchange reaction remains poorly understood. This study provides groundbreaking insights by systematically investigating the retention behavior of KI/AC versus non-impregnated activated carbons (NI AC) under different operating conditions. Advanced characterization techniques, including N₂ porosimetry, high-resolution transmission electron microscopy (HRTEM), and H₂O adsorption isotherms, were first employed to elucidate the structural and chemical properties of the adsorbents. Subsequently, CH₃¹³¹I retention tests were conducted by measuring the Decontamination Factors (DF) at various configurations covering a broad range of relative humidities (RH) (20–90 %), temperatures (20–96 °C), residence times (0.125–0.5 s) and elution times (1–18 h). Results reveal that while NI AC exhibits a drastic performance decline at high RH attributable to water physisorption, KI/AC demonstrates enhanced retention, counterbalancing moisture effects via isotopic exchange. Furthermore, elevated temperatures significantly amplify DF for KI/AC, unveiling for the first time the thermally activated nature of the isotopic exchange mechanism. Prolonged residence time further enhance performance for KI/AC compared to NI AC, suggesting multiple mechanistic steps in isotopic exchange reaction. Consequently, a detailed mechanism for this reaction has been proposed.

This work advances the understanding of CH₃¹³¹I capture mechanisms ensuring improved performance under diverse nuclear safety scenarios.

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来源期刊

Journal of Nuclear Materials 工程技术-材料科学：综合

CiteScore

5.70

自引率

25.80%

发文量

601

审稿时长

63 days

期刊介绍： The Journal of Nuclear Materials publishes high quality papers in materials research for nuclear applications, primarily fission reactors, fusion reactors, and similar environments including radiation areas of charged particle accelerators. Both original research and critical review papers covering experimental, theoretical, and computational aspects of either fundamental or applied nature are welcome. The breadth of the field is such that a wide range of processes and properties in the field of materials science and engineering is of interest to the readership, spanning atom-scale processes, microstructures, thermodynamics, mechanical properties, physical properties, and corrosion, for example. Topics covered by JNM Fission reactor materials, including fuels, cladding, core structures, pressure vessels, coolant interactions with materials, moderator and control components, fission product behavior. Materials aspects of the entire fuel cycle. Materials aspects of the actinides and their compounds. Performance of nuclear waste materials; materials aspects of the immobilization of wastes. Fusion reactor materials, including first walls, blankets, insulators and magnets. Neutron and charged particle radiation effects in materials, including defects, transmutations, microstructures, phase changes and macroscopic properties. Interaction of plasmas, ion beams, electron beams and electromagnetic radiation with materials relevant to nuclear systems.