Use of a Matrix Diagram in Modelling Coupled Transport Processes in Performance Assessment

摘要

This paper describes how information on geosphere-transport processes is assimilated into the modelling of a disposal system for post-closure performance assessment. This description is based upon the overall iterative approach used by Nirex whereby performance assessments follow a cyclical development process. The production and use of a matrix diagram is an integral part of the Nirex model development programme, providing a clear audit trail from the identification of significant Features, Events and Processes (FEPs), to the models and modelling processes employed within a detailed safety assessment. As detailed in References [1-5], a five stage approach has been adopted, providing a systematic framework for addressing uncertainty and for documenting all modelling decisions and assumptions: Stage 1: FEP Analysis - compilation and structuring of a FEP database; Stage 2: Scenario and Conceptual Model Development; Stage 3 Mathematical Model Development; Stage 4: Software Development; Stage 5: Confidence Building.