Release of radioactive isotopes from damaged fuel

The activity release from damage fuel rods after the Paks-2 cleaning tank incident was estimated on the basis of coolant activity concentration measurements and chimney activity data. The release rates indicated that there were significant differences between the release of different elements. The typical release rate of noble gases, iodine and cesium was 1-2 %, but e.g. the release rate of ruthenium was only ∼ 0.01-0.04%. The dissolution rate of the uranium-dioxide was 0.3% during the first year, after the incident. (author)