Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS


RETROCK Sintesi della relazione

Project ID: FIKW-CT-2001-20201
Finanziato nell'ambito di: FP5-EAECTP C
Paese: Switzerland

WP1 report


- There is a high degree of confidence in the completeness of the list of potentially relevant transport and retention processes, although this list cannot be considered complete in a rigorous sense and new facts and new interpretations of results can never be excluded.

- The general approach is to model flow with a high degree of detail, aiming at a realistic representation of the flow field, and to adopt a more simplified approach to the modelling of transport.

- Transport is generally modelled along one or more transport paths or streamtubes identified by flow modelling, with transport parameters spatially averaged along these features.

- There are very few differences between PA transport models in the transport and retention processes that are included, the principal difference being the inclusion or exclusion of colloid-related processes.

- A number of processes potentially contribute to transport and retention, but are currently excluded from transport models, mostly due to lack of the data necessary for modelling and mostly justified on the grounds of conservatism (e.g. sorption on fracture surfaces and infill, diffusion into stagnant water caused by constrictions in fracture openings, diffusion into fracture infill or gouge material, immobilisation processes).

- There is generally satisfaction with the adequacy of fundamental understanding of the processes included in transport models (at least for PA modelling purposes), although an improved mechanistic understanding of sorption would be desirable.

- The processing or upscaling of data in order to obtain PA model parameter values is an area that warrants more attention in the future.

- The lack of, or limited, treatment of time-dependence is generally seen as a weakness in most current PA transport models.

The WP1 report was produced as Nagra's Internal Report but it is available on request from Nagra.

The result was fed as an interim result into the WP2.


Jurg SCHNEIDER, (Section Head Safety Analysis)
Tel.: +41-56-4371302
Fax: +41-56-4371317