PNNL

Abstract

Advanced Small Modular Reactors (AdvSMRs) are considered important future energy sources. However, in-vessel radiation fluxes are high and demands infrared (IR) optical fiberbased chemical sensing at temperatures that often exceed 400°C. This is a challenging environment for many current IR glasses, including covalently-bonded selenides and tellurides, such as As2Se3 and GeTe2, due their glass transition temperatures (Tg) being on the order of 200-350 °C. This work focuses on ?-irradiation affects at high temperatures on refractory ionic bonding based chalcogenide glasses in the BaS-La2S3-GeS2 system. Optical and selected physical properties were characterized before and after irradiation. It was found that both GeS2 and the 20BaS + 20La2S3 + 60GeS2 composition (in mole%) have minimal property changes when irradiated at 2.5 MGy cumulative dose at 300 °C. Sample density showed the largest characteristic change where densities initially decreased at 2 kGy dose, and then recovered at the highest dose of 2.5 MGy, resulting in an overall density change between 0.3 to 2%, depending on sample and composition. This work suggests the BaS-La2S3-GeS2 system as one for continued exploration as high temperature IR fiber sensors in radiation environments.