The Abundance of Fission Gases in the Off Gas of a Boiling Water Reactor

The release of gaseous radioactive fission products (xenon and krypton) from defective fuel pins is described with a one-dimensional transport model. Comparison of the measured quantities of xenon and krypton with calculated values from the model yields estimates of the number of defective pins and the surface contamination of the core. Furthermore, an indication of the average leak size is obtained. This is demonstrated using gas release data from previous fuel cycles of the 54-MW(electric) Dodewaard boiling water reactor.