Adsorption of actinides within speleothems
| Autor: | Nilesh L. Dudwadkar, S. C. Tripathi, Pranesh Sengupta, P.M. Gandhi, Jaishri Sanwal |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Calcite
geography geography.geographical_feature_category Aragonite Geochemistry Radioactive waste Speleothem Mineralogy Sorption Stalagmite 02 engineering and technology engineering.material 010502 geochemistry & geophysics 021001 nanoscience & nanotechnology 01 natural sciences chemistry.chemical_compound Cave chemistry Geochemistry and Petrology engineering Botryoidal 0210 nano-technology Geology 0105 earth and related environmental sciences |
| Zdroj: | Mineralogical Magazine. 80:765-780 |
| ISSN: | 1471-8022 0026-461X |
| DOI: | 10.1180/minmag.2016.080.013 |
| Popis: | Stalagmites and stalactites, as observed within natural caves, may develop inside geological repositories during constructional and post-operational periods. It is therefore important to understand actinide sorption within such materials. Towards this, experimental studies were carried out with233U,238Np (VI),238Np (IV),239Pu and241Am radiotracers using natural speleothem samples collected from the Dharamjali cave of the Kumaon Lesser Himalayas, India. Petrological/mineralogical studies showed that natural speleothems have three general domains: (1) columnar calcite; (2) microcrystalline calcite; and (3) botryoidal aragonite – each with ferruginous materials. Results showed that all domains of speleothems can take up >99% actinides, irrespective of valence state and pH (1–6 range) of the solution. However, distribution coefficients were found to be at a maximum in aragonite for most of the actinides. Such data are very important for long-term performance and safety assessments of the deep geological repositories planned for the disposal of high-level nuclear wastes. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|