Host: Japan Association of Mineralogical Sciences
Selenium-79 in high-level radioactive waste needs to be safely disposed in geological repository. However, Se has low affinity against various sorbents due to the common anion species. On the other hand, apatite was proposed as an efficient sorbent for anion species. In order to understand the mechanism of Se sequestration by apatite and pyromorphite in the Se-Pb-P-O system, we have conducted selenite immobilization experiments by hydroxyapatite and hydroxypyromorphite. In the experiment using hydroxypyromorphite, the secondary Pb-selenite, molybdomenite, precipitates. In the experiment of selenite sequestration during hydroxypyromorphite formation, selenite coprecipitates with hydroxypyromorphite.
