Äspö model for radionuclide sorption

In a worst-case scenario of a failed underground repository for radioactive waste, the host rock is the last barrier to prevent the transport of radionuclides to the biosphere. For safety assessment of a final repository, it is therefore essential to quantify the retention properties of the host rock. Commonly, empirical models, based on site-specific small-scale laboratory studies, are used to quantify sorption of radionuclides to the geological material, contributing to geochemical retention of the radionuclides. However, process-based models are needed to demonstrate process understanding and provide predictive tools that can be used over a range of geochemical conditions and rock characteristics.

This project aims at providing process-based models for the sorption of Cs, Sr, Ni and Eu to geological material from the Äspö site in Sweden. Steps in achieving this goal includes to study the specific surface area and sorption properties of pure minerals and site specific geological material as function of particle size. It is also includes determination of the location of the sorbed radionuclides on the solid material through autoradiography. Based on literature data and experimental findings in the project, predictive models for radionuclide sorption will be proposed and tested, using laboratory data.

Project leader:
Maria Malmström KTH

Project participants:
Industrial Ecology KTH, Nuclear Chemistry CTH

Funding:
SKB

Contact:
Ass. Professor Maria Malmström