Leaching tests are conducted according to different standards, pro- cedures or recommendations, generally under conditions different from those of the disposal media. Such tests are generally useful for com- paring various containment matrices to ensure maximum isolation of radionuclides, and allow waste conditioning processes to be optimized. However, when defining release hypotheses to be taken into consideration for risk analysis, these methods can often lead to hypothesis which are either too optimistic or too pessimistic. The uncertainties basically involve the processes by which...