Preliminary radioiodine source-term and inventory assessment for TMI-2

The results of an analysis of radioiodine behavior during and after the March 28, 1979 accident at TMI-2 are presented. All available measurement data for /sup 129/I and /sup 131/I are summarized. Measurements show that from 17% to 28% of the iodine originally in the fuel could be accounted for outside the core on August 28, 1979 (when the first basement water sample was taken). To fill in gaps where measurements are not available mathematical models are used. Models for the transport of iodine from the fuel to the Reactor Building are developed and benchmarked to measurements. It is estimated that approximately 1% of the iodine originally in the fuel was made airborne during the accident, and the maximum air concentration during the accident resulted from transport of 0.2% of the original core inventory.