In geological disposals for nuclear or toxic wastes, cement plays a crucial role to maintain its structural stability. In addition, the phases present in the hydrated cement can bind toxic or radioactive elements, which prevents or slows down their release from the disposal site. The transport of toxic or radioactive elements can be accelerated by organic molecules in solution, as some organic molecules can complex toxic or radioactive ions increasing its concentrations and thus accelerating transport.

The uptake of small organic molecules: formate, gluconate and citrate, on common cement hydrates such as C-S-H, ettringite and AFm phases is determined. In a second step the effect of dissolved and bound organic molecules on the concentrations of different radionuclides will be determined to understand the impact of formate, citrate and gluconate on the uptake of radionuclides (Nd, Eu, Pu, Am, Cm) by cement phases and on cement

Project Period

November 2019 - October 2022