[en] We have designed leaching systems for experiments on several kinds of solids, including glassy debris from underground nuclear explosions at Nevada Test Site (puddle glass), refractory compositions for retention of radioactive nuclear reactor waste, and spent reactor fuel. The system used on puddle glass has a continuously variable flow rate from 13 to 460 cm³/d, a temperature range from 25 to 75⁰C, operating capacity for up to 20 simultaneous experiments, and one-pass operation with continuous exposure of samples to fresh solution. Results obtained on puddle glass are in qualitative agreement with those on silicate glasses designed for isolation of nuclear reactor waste