This International Standard specifies an analytical method for determining the solubility in nitric
acid of plutonium in pellets of unirradiated mixed oxide fuel (light-water reactor fuels). The results
provide information about the expected dissolution behaviour of irradiated pellets under industrial
reprocessing conditions. In this aspect, the specific conditions (e.g. time of the test) may vary depending
upon the need to match to a specific reprocessor’s requirements. The test is aimed at determining
solubility under equilibrium conditions rather than the kinetics of dissolution and hence allows for a
second dissolution period.