6.74. The aim of this section is to address the implications arising for the preparation of the safety case and safety assessment if the disposal concept is intended to provide for retrievability of waste. The more general concept of reversibility denotes the possibility of reversing one or a series of steps in the planning or development of the disposal facility. This implies the review and, if necessary, re-evaluation of earlier decisions, as well as availability of the means (technical, financial, etc.) to reverse a step. Retrievability denotes the possibility of reversing the action of waste emplacement. It is, thus, a special case of reversibility. Retrieval is the action of recovery of waste or waste packages [40].