Monitoring of the iron and oxygen impurities in liquid sodium by laser-induced breakdown spectroscopy with a gas protection component

Abstract

Sodium is a preferred coolant in Generation IV nuclear reactors due to its excellent heat transfer and nuclear properties. However, decreased cooling efficiency, material corrosion and blockages can be caused by excessive amounts of impurities in the sodium. Conventional detection methods are unable to realize rapid, in situ, sensitive and accurate online sodium impurity monitoring owing to factors such as equipment size, service life and detection time. In this study, a laser-induced breakdown spectroscopy device with a gas protection component was proposed. This design not only prevents sodium aerosols or liquid sodium splashing from contaminating the optical lens, but also enables sensitive analysis of Fe and O in sodium, with limits of detection of 0.68 µg g⁻¹ and 0.11 µg g⁻¹ and RSDs of 7% and 4%, respectively. The results demonstrated that this method has potential application prospects in the nuclear industry and could provide a guarantee for the safe operation of sodium-cooled fast reactors.