Numerical dispersion in the SKB model Importance of

A major recommendation of this paper is that AG-1478 assessments need to justify the degree of complexity in modelling approaches as well as simplifying and conservative assumptions. Technical and non-technical audiences need to have confidence in assessment results. Confidence is built on transparency and understanding, which become more challenging as the degree of complexity increases. The choice of assessment approach is a decision for the organisations and individuals undertaking assessments and will reflect that which they understand best makes a robust safety case. In light of the uncertainties concerning the biosphere on very long timescales, stylised biosphere models are shown to provide a useful point of reference in themselves and remain a valuable tool for nuclear waste disposal licencing procedures.
AcknowledgementsThis paper is based on work undertaken on behalf of the Swedish Radiation Safety Authority (SSM). SKB\'s work in describing the biosphere system at Forsmark and its potential evolution into the future is also acknowledged, as is its kind permission to reproduce figures from its reports.