Immobilization of NPP evaporator bottom high salt-bearing liquid radioactive waste into struvite-based phosphate matricesстатья
Статья опубликована в высокорейтинговом журнале
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 7 июля 2021 г.
Аннотация:The high salt-bearing liquid radioactive waste (evaporator bottoms, EB) makes up the most voluminous NPPwaste and needs solidification. In the paper presented, we introduce a novel formation process study of thestruvite-based phosphate matrices ((K, NH4)MgPO4⋅6H2O) and the developed phosphate matrix compositions forthe solidification of high salt-bearing solutions. The solutions simulate the EB of nuclear power plants withpressurized water reactors (NPP PWR). The effect of the EB’s composition and salt content on the matrices’mechanical strength was investigated. The cesium-selective nickel-potassium ferrocyanide sorbent or 10–20% ofMgO over the reaction stoichiometry, introduced at the matrix synthesis stage, allowed the production ofmatrices with the average 137Сs leach rate of less than 10-3 g cm-2 day-1 and the mechanical strength over 5 MPa.The matrices obtained completely satisfied the cemented radioactive waste requirements and contained up to17–17.5 wt% of salts, which was 1.7–2.5 times higher compared to the Portland cement-based matrices.