Temperature dependent volatilisation behaviour of Cs from two commercial adsorbents used at Fukushima measured using novel experimental apparatus

Results from a custom-built experimental volatilisation apparatus are presented. The apparatus consists of a tubular furnace to volatilise and then entrain the volatilised species into a cooled segment to reprecipitate for collection. This design allows for meticulous collection of the volatilised species, which are then analysed with atomic absorption spectroscopy. This paper includes an evaluation of the apparatus and a comparative study of the temperature dependence of Cs volatilisation from two commercial adsorbents. The Cs volatilisation from A-51 JHP and IE-96 was examined from 600 °C to 1000 °C. At 1000 °C the relative volatilisation was found to be 1.67% for A-51 JHP and 0.097% for IE-96. As the adsorbents requiring immobilisation contain volatile Cs species, the temperature dependence of this behaviour is important as it will affect Cs retention during the immobilisation process. Evaluation of the volatilisation apparatus showed it to be a reliable method to measure volatisation behaviour from adsorbents. •Cs-contaminated adsorbents form a volatile waste stream with no volatilisation data available of modern adsorbents.•Temperature dependent volatilisation behaviour of Cs from adsorbents was measured using a novel experimental apparatus.•Modular experimental apparatus consisted of a tube furnace with cooled reprecipitation chamber.•Commercial adsorbents loaded with Cs exhibited Cs volatilisation behaviour at temperatures below 1000 °C.•Cs volatilisation behaviour differs per adsorbent, higher selectivity correlated to higher volatilisation temperatures.