4.73. Limits and conditions of particular importance for disposal facilities are the total waste inventory acceptable and/or the acceptable concentration levels for specific radionuclides in the waste. These should be defined and/or justified on the basis of the safety assessment. Waste acceptance criteria should be established both for individual packages and for the entire facility by considering the analysis of various scenarios (e.g. for the release of radionuclides to the environment and for transfer of radionuclides along environmental pathways). Consideration of human intrusion scenarios is also important and is often used to determine the acceptable levels of long lived radionuclides in the case of near surface disposal facilities. It should be noted, however, that large quantities of short lived radionuclides can also present potential problems, particularly for operational safety, and such radionuclides should also be considered in the safety assessment and in specifying limits on the inventory and on concentration levels. In addition, the safety case should also be used to assess the levels of (e.g. chemical) substances in the waste or the engineered barriers that may cause degradation of the natural and engineered barriers. Further details on the derivation of waste acceptance criteria for near surface disposal facilities are provided in Ref. [33].