The role of natural analogues in safety assessment and acceptability

Abstract

The safety assessment must evaluate the level of safety for a repository, the confidence that can be placed on the assessment and how well the repository can meet the acceptance criteria of the society.

Many of the processes and phenomena that govern the long term performance of a deep geologic repository for radioactive waste also take place in nature. To investigate these natural analogues and try to validate the models on which the safety assessments are based is a main task in the effort to build of confidence in the safety assessments.

The assessment of the safety of a repository can, however, not only be based on good models. The possible role of natural analogues or natural evidence in other parts of the safety assessment is discus sed. Specially with regard to

• the need to demonstrate that all relevant processes have been taken into account, and that the important ones have been validated to an acceptable level for relevant parameter spans,

• the definition and analysis of external scenarios for the safety assessment and for the claim that all reasonable scenarios have been addressed,

• the public confidence in the long-term relevance of the acceptance criteria.