Release of iodine from sintered thoria pellets at low temperatures

Post-irradiation thermal release behaviour of ¹³¹I from low-dose irradiated sintered ThO₂ pellets (~5.5 × 10²⁰ fissions/ m³) of average density 79% and 90% TD has been studied in the temperature range 723–1373 K. The possible mechanism of release has been discussed. The kinetics of burst release have been worked out and presented. The release behaviour of ¹³¹I has also been studied from high-dose irradiated ThO₂ pellets (~1.1 × 10²³ fissions/m³). These have shown an increase in diffusivity.