6.47. On the basis of such considerations, the lifetime of the disposal facility may be covered by using one or more sets of assessment calculations. In such cases, it should be shown, to the extent possible, that the calculations together cover the entire period and that consistent assumptions have been made throughout the assessment period or that inconsistencies are well justified. In some cases, differing or even inconsistent assumptions may be made to demonstrate safety for different assessment periods, because assumptions may be made that are conservative for a specific period, but which do not necessarily also have to be conservative for another period. For example, an assumption made concerning the release of radioactive material during the operational period may be conservative, while for the post-closure period the assumption that the full inventory still remains in the facility may be conservative. In such cases, deliberately introduced differences and contradictions in assumptions should be carefully documented and justified in order not to discredit the overall safety case as being based on inconsistent assumptions.