Experimental Measurements of Volatility of Fission-Product Iodine Released from Irradiated CANDU Fuel in High-Temperature Steam Environment: Tests I1 and I2 in The HCE5 Experiment

Abstract

Sheathed samples of irradiated UO₂ were heated in flowing steam to 1930 K and 2010 K, in order to investigate the volatility of iodine released from CANDU® fuel. Iodine volatility was measured in these two tests by γ-scanning of short-lived iodine isotopes on particulate and charcoal filters within a few hours after exposure to air. Final fractional releases of I, Cs and Mo isotopes were about 70% in both tests. No significant quantities of volatile iodine were found (probably less than 0.1% of the iodine that reached the particulate filters), which supports the approach used to assess iodine volatility in containment for CANDU 6 licensing.