Arbeitsbericht NAB 12-52

Speciation Calculations Supporting the Sorption Data Bases for Argillaceous Rocks and Bentonite for the Provisional safety Analyses for SGT-E2

This report documents the speciation calculations that were made to support the sorption data bases for argillaceous rocks and bentonite for the provisional safety analyses for SGT-E2 (Baeyens et al. 2014).

Speciation calculations were carried out for Be(II), Co(II), Ni(II), Se(-II), Zr(IV), Nb(V), Tc(IV), Pd(II), Ag(I), Sn(IV), Sm(III), Eu(III), Ho(III), Pb(II), Ra(II), Th(IV), Pa(V), U(IV, V, VI), Np(IV), Pu(III, IV, V, VI), Am(III), and Cm(III) in porewaters for Opalinus Clay and 'Brauner Dogger', the Effingen Member, Helvetic marls, and MX-80 bentonite.

For the selection of source sorption values from experiments with illite, speciation calculations were also made for several radionuclides in 0.1 M NaClO4 at the different pH values of the hostrock and bentonite porewaters.

Chapter 2 describes how the speciation calculations were carried out with the PHREEQC code, provides templates for creating the necessary input files, lists the names of the output files that were produced, and compiles the resulting speciations.

Chapter 3 describes the structure of the data files and lists all thermodynamic data used in the speciation calculations.

The information contained in this report is needed to reproduce all considered speciation calculations.