Sorption databases for increasing confidence in performance assessment

dc.contributor.authorRichter, Aen_AU
dc.contributor.authorBrendler, Ven_AU
dc.contributor.authorNebelung, Cen_AU
dc.contributor.authorPayne, TEen_AU
dc.contributor.authorBrasser, Ten_AU
dc.date.accessioned2024-10-03T22:54:46Zen_AU
dc.date.available2024-10-03T22:54:46Zen_AU
dc.date.issued2009-10-11en_AU
dc.date.statistics2024-10-04en_AU
dc.description.abstractWorld-wide activities focus on the remediation of radioactively contaminated sites. One common aim is to deliver a more profound chemical base for risk assessment, namely all those physico-chemical phenomena governing the contamination plume development in time and space. Coupled transport codes able to tackle this challenge have to simplify the resulting very complex reaction pattern. To do so in an adequate way requires extending the knowledge about retardation and mobilisation phenomena and the underlying basic processes and interactions (e.g. physisorption, chemisorption, surface precipitation). Interactions at the solid-liquid interface can be described by complementary approaches, the empirical Kd concept and the mechanistic Surface Complexation Models (SCM). Kd’s are used by most reactive transport and risk assessment codes due to the straightforward numerics involved. In addition, the Kd concept is often the only feasible option for complex solid phases. However, the Kd concept is a rather simplistic approach. Many very different basic physico-chemical phenomena are subsumed in just one conditional parameter. Therefore, extrapolating Kd values may yield very large uncertainties. SCM account adsorption of ions on surface sites as complexation reaction comparable to complexation in solution. The electrical charge at the surface is determined by the chemical reactions of the mineral functional groups, including acid-base reactions and formation of ion pairs and coordinative complexes. The required parameters are site-independent and applicable despite large variations in geochemical conditions. This presents a high potential to increase confidence in safety analysis and risk assessment studies (performance assessment). The mechanistic description of sorption processes with SCM allows a thermodynamically consistent calculation of the species distribution between liquid and solid phase combined with more reliable inter- and extrapolations. However, this requires that all mineral constituents of the solid phase are characterized. Another issue is the large number of required parameters combined with time-consuming iterations. Addressing both approaches, we present two sorption databases, developed mainly by or under participation of the Forschungszentrum Dresden-Rossendorf (FZD). Both databases are implemented as relational databases, assist identification of critical data gaps and the evaluation of existing parameter sets, provide web based data search and analyses and permit the comparison of SCM predictions with Kd values. RES3T (Rossendorf Expert System for Surface and Sorption Thermodynamics) is a digitized thermodynamic sorption database (see www.fzd.de/db/RES3T.login) and free of charge. It is mineral-specific and can therefore also be used for additive models of more complex solid phases. ISDA (Integrated Sorption Database System) connects SCM with the Kd concept but focuses on conventional Kd. The integrated datasets are accessible through a unified user interface. An application case, Kd values in Performance Assessment, is given. © 2009 by ASMEen_AU
dc.identifier.booktitleASME 2009 12th International Conference on Environmental Remediation and Radioactive Waste Managementen_AU
dc.identifier.citationRichter, A., Brendler, V., Nebelung, C., Payne, T. E., & Brasser, T. (2011). Sorption databases for increasing confidence in performance assessment. Paper presented to the "ASME 2009 12th International Conference on Environmental Remediation and Radioactive Waste Management. In Proceedings of the ASME 2009 12th International Conference on Environmental Remediation and Radioactive Waste Management, October 11-15, 2009, Liverpool, UK. (Vol. 1, pp. 361-367). doi:10.1115/ICEM2009-16053en_AU
dc.identifier.conferenceenddate2009-10-15en_AU
dc.identifier.conferencenameASME 2009 12th International Conference on Environmental Remediation and Radioactive Waste Managementen_AU
dc.identifier.conferenceplaceLiverpool, United Kingdomen_AU
dc.identifier.conferencestartdate2009-10-11en_AU
dc.identifier.isbn9780791844076en_AU
dc.identifier.pagination361-367en_AU
dc.identifier.urihttp://dx.doi.org/10.1115/icem2009-16053en_AU
dc.identifier.urihttps://apo.ansto.gov.au/handle/10238/15719en_AU
dc.identifier.volume1en_AU
dc.language.isoenen_AU
dc.publisherASME Internationalen_AU
dc.subjectLow-level radioactive wastesen_AU
dc.subjectDataen_AU
dc.subjectSorptionen_AU
dc.subjectMineralsen_AU
dc.subjectRisk assessmenten_AU
dc.subjectChemical reactionsen_AU
dc.subjectContaminationen_AU
dc.subjectElectric chargesen_AU
dc.subjectExpert systemsen_AU
dc.subjectIonsen_AU
dc.subjectPlumesen_AU
dc.subjectThermodynamicsen_AU
dc.subjectUncertainty principleen_AU
dc.titleSorption databases for increasing confidence in performance assessmenten_AU
dc.typeConference Paperen_AU
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