Skip to Main content Skip to Navigation
Conference papers

Physico-chemical interactions at the concrete-bitumen interface of nuclear waste repositories

Abstract : This study investigates the fate of nitrate and organic acids at the bitumenconcrete- steel interface within a repository storage cell for long-lived, intermediatelevel, radioactive wastes. The interface was simulated by a multiphase system in which cementitious matrices (CEM V-paste specimens) were exposed to bitumen model leachates consisting of nitrates and acetic acid with and without oxalic acid, chemical compounds likely to be released by bitumen. Leaching experiments were conducted with daily renewal of the solutions in order to accelerate reactions. C-steel chips, simulating the presence of steel in the repository, were added in the systems for some experiments. The concentrations of anions (acetate, oxalate, nitrate, and nitrite) and cations (calcium, potassium, ammonium) and the pH were monitored over time. Mineralogical changes of the cementitious matrices were analysed by XRD. The results confirmed the stability of nitrates in the absence of steel, whereas, reduction of nitrates was observed in the presence of steel (production of NH4+). The action of acetic acid on the cementitious matrix was similar to that of ordinary leaching; no specific interaction was detected between acetate and cementitious cations. The reaction of oxalic acid with the cementitious phases led to the precipitation of calcium oxalate salts in the outer layer of the matrix. The concentration of oxalate was reduced by 65% inside the leaching medium.
Complete list of metadata

Cited literature [44 references]  Display  Hide  Download

https://hal.inrae.fr/hal-02749961
Contributor : Migration Prodinra <>
Submitted on : Wednesday, June 3, 2020 - 4:24:57 PM
Last modification on : Friday, September 24, 2021 - 3:01:36 AM

File

2012_Bertron_3rd International...
Files produced by the author(s)

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Collections

Citation

Alexandra Bertron, Harifidy Ranaivomanana, Nicolas Jacquemet, Benjamin Erable, Caroline Sablayrolles, et al.. Physico-chemical interactions at the concrete-bitumen interface of nuclear waste repositories. 3rd International Workshop on NUCPERF, Nov 2012, Cadarache, France. pp.10, ⟨10.1051/epjconf/20135601002⟩. ⟨hal-02749961⟩

Share

Metrics

Record views

46

Files downloads

88