Session: 05-04: Investigations of Cement Based Materials and Waste Matrices

Paper Number: 110309

110309 - Organic-Cement Interactions in the Frame of the Cori (Cement-Organic-Radionuclide-Interactions) Wp Within the Eurad Ec Project 

The CORI (Cement-Organics-Radionuclides-Interactions) Workpackage integrated into EURAD (EURAD – European Joint Programme on Radioactive Waste Management, https://www.ejp-eurad.eu) performs research to improve the knowledge on the organic release issues which can accelerate the radionuclide migration in the context of the post closure phase of geological repositories for ILW and LLW/VLLW including surface/shallow disposal. The R&D in CORI extends the current state-of-the-art and will contribute to optimize disposal solutions and consider questions of regulatory concern. CORI results will help member states to further develop their national R&D programs and support programs at an early implementation stage. CORI has prepared a State-of-the-Art document which gives an introduction to the main research topics targeted in CORI (available at: https://www.ejp-eurad.eu/publications/eurad-deliverable-31-cori-sota-cement-organic-radionuclide-interactions-content-lilw), that will be update in 2024 with main results gathered in the context of the project.

The three R&D Tasks in CORI to be introduced with the aim of indicating how CORI contributes to develop optimized understanding of cement-organics-radionuclide-interactions are: (i) Organic Degradation, (ii) Organic-Cement-Interactions, (iii) Radionuclide-Organic-Cement-Interactions. Organic materials are present in some nuclear waste and as admixtures in cement-based materials and can potentially influence the performance of a geological disposal system, especially in the context of low and intermediate level waste disposal. CORI research in Task 3, Organic-Cement interactions, addressed the sorption behaviour of several organics (Isosaccharinate (ISA) or cellulose degradation products, Phthalate, EDTA, NTA, 3-hydroxy-butirate, alpha-hydroxy-butiric acid, Glutarate, Formate, Citrate, Acetate, Oxalate, Adipate) including superplasticizers (and their degradation products) on a range of cementitious systems (CSH, CASH, Ca(OH)₂, AFm, AFt, Hardened Cement Paste in different degradation stages). The potential effect of organic molecules investigated in Task 3 is related to the formation of complexes in solution with major elements as well as on their capability in blocking sorption sites from the cement surface (decreasing an eventual radionuclide sorption). A brief summary of results generated by the different partners of the project, Andra, Amphos 21, CEA, CIEMAT, CSIC, CVREZ, Helsinki University, JSI, KIT, PSI, EMPA, RATEN, SCK-CEN, SURAO, CTU, UJV, and the synthesis of the main conclusions will be presented in this contribution.

Acknowledgement: The project leading to this application has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 847593.

Presenting Author: David García Cobos Amphos 21

Presenting Author Biography: David Garcia is Head of the Radioactive Waste Management Department at Amphos 21 (Spain). His research experience includes geochemical modelling from the source-term (Radionuclide release, EBS, metals corrosion, secondary phase formation, etc.) to the near-field (radionuclide transport through the host-rock, modelling solubility and sorption processes, etc.). During the last 15 years, David has been actively participating in several European projects in both technical and management tasks, dealing in most cases with geochemical modelling of complex systems.