Data for: Off-Gas Rhenium Capture and Recovery in a Laboratory-Scale Melter

The path for immobilizing low-activity waste (LAW), a mixture of salts, for long-term storage is adding glass-forming and modifying additives and minerals to the solution and vitrifying the resulting slurry in an electric melter. Technetium-99 (99Tc), a long-lived radionuclide present in LAW, is highly volatile at the elevated temperatures in a glass melt. An off-gas system was designed for capturing volatile 99Tc or Re, its nonradioactive surrogate, during continuous charging of a LAW melter feed in a laboratory-scale melter (LSM). The Re retention in the glass was determined via the measured amount of volatilized Re in the off-gas during a time period when the reacting melter feed was at a quasi-steady-state. This study was performed in preparation for the LSM system to be applied for melter feeds containing either a LAW simulant spiked with 99Tc or an actual tank waste.

针对以盐类混合物形式存在的低活性废物（low-activity waste，LAW）开展长期固化储存的常规方案，是向其溶液中添加玻璃形成剂、改性添加剂与矿物，再将所得浆料置于电熔炉中进行玻璃化处理。锝-99（Technetium-99，99Tc）作为存在于LAW中的长寿命放射性核素，在玻璃熔融的高温环境下具备极强的挥发性。本研究针对实验室规模熔炉（laboratory-scale melter，LSM）在连续投加LAW熔炉进料的工况，设计了一套尾气捕获系统，用于收集挥发性的99Tc或其非放射性替代物铼（Re）。当反应中的熔炉进料处于准稳态时段时，通过测定尾气中挥发的铼含量，即可确定玻璃中铼的留存率。本研究的开展，旨在为后续将该LSM系统应用于两类熔炉进料提供前期支撑：一类为掺加了99Tc的LAW模拟物，另一类则为实际储罐废液。