Forschungs- & Entwicklungsinformationsdienst der Gemeinschaft - CORDIS

FP5

RETROCK Berichtzusammenfassung

Project ID: FIKW-CT-2001-20201
Gefördert unter: FP5-EAECTP C
Land: Sweden

WP2 report

DESCRIPTION OF THE SCIENTIFIC RESULT / CONCLUSION:

The processes emphasised in the report are the influences of the flow field, matrix diffusion, and sorption on radionuclide transport characteristics. These processes, and radioactive decay, provide the key terms to the transport equations of the performance assessment (PA) models. The following processes are handled more cursorily: colloid-facilitated transport, microbial activity, gas-mediated transport, precipitation/coprecipitation, and off-diagonal Onsager processes.

The PA models usually take into account retention phenomena using simplified concepts that are justified by their conservatism. They are complemented by a large variety of more detailed and realistic process-specific models that can be used to support the choice of data for PA models, as well as specific arguments made in safety cases. While the fundamental understanding, the conceptualisations of the phenomena, the models and the computing resources develop, the extensive data requirements often become a most restrictive factor to the use of a model. The difficulties in obtaining data tend to hinder the utilisation of the most realistic mechanistic models, but major challenges are also encountered in obtaining relevant and defensible data for the principal simplified PA models.

All processes discussed in the report were mentioned in the responses to a questionnaire that was used in WP1 to map the views and the ways to handle the topic in several published safety cases.

DISSEMINATION OF THE RESULT:

The WP2 report was published as SKB Report R-04-48.

In addition, the sections on matrix diffusion were reported as the following public report: Jakob A. (2004), Matrix Diffusion for Performance Assessment - Experimental Evidence, Modelling Assumptions and Open Issues. Nagra Technical Report 04-07 and Paul Scherrer Institut Bericht Nr. 04-08, July 2004.

USE OF THE RESULT:

The report served as a tool for further judgement of understanding and approaches, and for an assessment of development needs. Thus it was a major input to WP3. In addition, the draft was used to acquire feedback to RETROCK from external reviewers and the other attendees of the Specialist Workshop at the midterm of the project.

Verwandte Informationen

Reported by

SVENSK KAERNBRAENSLEHANTERING AB
Box 5864
102 40 STOCKHOLM
Sweden
See on map
Folgen Sie uns auf: RSS Facebook Twitter YouTube Verwaltet vom Amt für Veröffentlichungen der EU Nach oben