Automated analysis of effluents from nuclear facilities for ⁵⁵Fe and⁶³Ni

Anthropogenic ⁵⁵Fe and ⁶³Ni are key radionuclides in liquid effluents from nuclear facilities and are of great concern for environmental radiological impact assessment. While various analytical methods have been reported, they rely on manual operations, making them time-consuming, labor-intensive, and unsuitable for on-line or in-situ monitoring. This study presents a fully automated sequential-injection system that integrates precipitation pretreatment, dual-column chromatographic separation, and liquid scintillation detection, enabling rapid and in-situ analysis of ⁵⁵Fe and ⁶³Ni in nuclear effluents. The system incorporates programmable control algorithms to optimize parameters such as carrier volume, flow rate, and eluent concentration. It achieves high chemical yields-96 % ± 3 % for ⁵⁵Fe and 92 % ± 4 % for ⁶³Ni-with low analytical uncertainties (below 6 % and 7 %, 2σ). The system effectively eliminates matrix interferences, maintains robust performance under varied flow conditions, and enables fully automated processing of 1 L samples within 50 min. Compared to conventional manual methods, it significantly improves efficiency and reduces radiation exposure. This work demonstrates a promising platform for real-time radiological monitoring of effluents from nuclear facilities and is adaptable for other radionuclide analysis scenarios.