4.6. In accordance with the requirements of Ref. [IAEA SSR-5 (2011)] (see para. 3.8), a safety case is required to be developed to address safety during the operation of a disposal facility and after its closure. This Safety Guide focuses on safety in the post -closure period and provides guidance on the role and components of the safety case necessary to present all of the arguments and supporting assessment, analysis and evidence demonstrating the safety of a disposal facility. In this regard, the role of the safety case should be to provide:@@- Integration of relevant information in a structured, traceable and transparent way that demonstrates an understanding of the behaviour and performance of the disposal system in the period after closure;@@- Identification of uncertainties in the behaviour and performance of the disposal system, analysis of the significance of the uncertainties, and identification of approaches for the management of significant uncertainties;@@- Demonstration of long term safety by providing reasonable assurance that the disposal facility will perform in a manner that protects human health and the environment; @@- Support to decision making in the step by step approach to development of a disposal facility; @@- Facilitation of communication between interested parties on issues relating to a disposal facility.