Knowledge of physical parameters of solid ‘as generated’ RAW is impor­tant for some processing technologies, like compaction and pyrolysis. The requirement for the content and level of information should come from the facility operator and a methodology to determine the parameters shall be tailored accordingly.

Information on the physical and mechanical parameters of processed waste is substantially more important. Demonstration of key mechanical parameters of a waste form and the entire waste package is usually required by the WAC. This requirement comes from the projected long-term durabil­ity of the waste form (in particular for solidified liquid waste) and also from the design and arrangement of waste packages in the disposal facility, where placement of waste packages in several layers is commonly used. The last requirement is usually solved by use of verified and approved waste con­tainers, providing for sufficient mechanical stability for the entire waste package. Mechanical parameters of the waste form are controlled in the waste producer facility using samples taken during waste processing — the scope of control and methodologies should be developed according to the requirements of the WAC and the expectations/requirements of the disposal site operator.