Technical Report NTB 88-28

A PHREEQE Database for Pd, Ni and Se

This report presents a selection of thermodynamic data for Pd, Ni and Se to allow modelling of the speciation and solubility of these elements in repository safety analyses. Insufficient data are available in the literature to allow full appraisal of the data selected but, where possible, values were chosen from critical compilations or were checked for consistency between different sources. In an appendix, the data selected are presented in a format for direct use in the geochemical computer code PHREEQE.

The report also includes examples of use of the database to examine the behaviour of these elements in chemical systems relevant to the Swiss nuclear waste management programme. Limitations of application and possible future work in this field are also discussed.