SCK•CEN authors are displayed in bold
| Title: | Behaviour of Selenium in Boom Clay. State-of-the-art report |
| Author(s): | De Cannière, Pierre Maes, André Williams, Steve Bruggeman, Christophe Beauwens, Thomas Maes, Norbert Cowper, Mark |
| Keywords: | Se-79 sorption reduction precipitation solubility Boom Clay redox-disequilibrium reactive transport fission product diffusion retention transport parameters performance assessment uncertainty spent fuel high-level waste HLW radioactive waste disposal |
| Issue Date: | May-2010 |
| Publisher: | SCK•CEN, Mol, Belgium |
| Publication type: | Report |
| Citation: | De Cannière P., Maes A., Williams S., Bruggeman C., Beauwens T., Maes N., e.a.- Behaviour of Selenium in Boom Clay. State-of-the-art report.- Mol, Belgium: SCK•CEN, 2010.- 328 p.- (External Report of the Belgian Nuclear Research Centre; ER-120; CCHO-2004/00/00 DS251-A44/2.1).- ISSN 1782-2335 |
| Series/Report no.: | External Report of the Belgian Nuclear Research Centre |
| Abstract: | 79Se is considered as a key mobile fission product for nuclear waste disposal in the Boom Clay, the reference host formation presently studied in Belgium. Therefore, a good understanding of selenium migration behaviour through the clay barrier is essential to underpin its transport parameters selected for the performance assessment of a deep repository for spent fuel and high-level waste. Under the reducing conditions prevailing in Boom Clay, selenide, [Se(-II)], is the predominant thermodynamically stable chemical form of selenium. However, selenium may suffer of severe redox disequilibrium and selenate is very reluctant to reduction while a kinetically controlled sorption-reduction-precipitation behaviour is observed for selenite. Due to the large uncertainty on the speciation of selenium in the waste form, and taking the stability of selenate versus reduction into account, it is necessary to consider the non-solubility limited SeO42– as a possible migrating species. However, when a lower oxidation state [Se(IV), Se(0), and Se( II)] is present in the waste form, a solubility limit may also contribute to delay and attenuate the 79Se release. Therefore, two sets of transport parameters are proposed to PA: a first set for selenate (without solubility limit) and a second set for selenide (with solubility limit). |
| Persistent URL: | http://hdl.handle.net/10038/7079  |
| ISSN: | 1782-2335 |
| SCK•CEN Report Number: | ER-120 |
| Attachments: |
Items in this repository are protected by copyright, with all rights reserved, unless otherwise indicated.