Characterization of Corrision Deposits and the Assessment of Fission Products Released from Used CANDU Fueld

Abstract

Experiments were carried out to characterize corrosion deposits on used CANDU fuel and to study the release of fission products from intact and intentionally defected fuel bundles stored in air saturated with water vapour. This work is part of a joint Ontario Hydro/Atomic Energy of Canada Limited program to study the long-term behaviour of used CANDU fuel bundles stored in dry and moist air at 150 degrees C at the Whiteshell Nuclear Research Establishment near Pinawa, Manitoba, Canada. Results from the analysis of acid leachates from the sheath of nineteen Pickering and Bruce fuel elements show that the main inactive corrosion product was iron and the major radioisotopes were cesium-137 and strontium-90. Analysis of the water used to provide a moist environment in the stored fuel showed that fission products were leached from the defected fuels and that the major fission product was cesium-137.