Vinokurov Sergey E, Kulikova Svetlana A, Myasoedov Boris F
Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, 19 Kosygin st., Moscow 119991, Russia.
Materials (Basel). 2018 Jun 8;11(6):976. doi: 10.3390/ma11060976.
The problem of effective immobilization of liquid radioactive waste (LRW) is key to the successful development of nuclear energy. The possibility of using the magnesium potassium phosphate (MKP) compound for LRW immobilization on the example of nitric acid solutions containing actinides and rare earth elements (REE), including high level waste (HLW) surrogate solution, is considered in the research work. Under the study of phase composition and structure of the MKP compounds that is obtained by the XRD and SEM methods, it was established that the compounds are composed of crystalline phases—analogues of natural phosphate minerals (struvite, metaankoleite). The hydrolytic stability of the compounds was determined according to the semi-dynamic test GOST R 52126-2003. Low leaching rates of radionuclides from the compound are established, including a differential leaching rate of Pu and Am—3.5 × 10 and 5.3 × 10 g/(cm²∙day). As a result of the research work, it was concluded that the MKP compound is promising for LRW immobilization and can become an alternative material combining the advantages of easy implementation of the technology, like cementation and the high physical and chemical stability corresponding to a glass-like compound.
有效固定液态放射性废物（LRW）的问题是核能成功发展的关键。本研究工作以含有锕系元素和稀土元素（REE）的硝酸溶液为例，包括高放废物（HLW）替代溶液，探讨了使用磷酸镁钾（MKP）化合物固定LRW的可能性。通过XRD和SEM方法对所得MKP化合物的相组成和结构进行研究，确定该化合物由结晶相组成，即天然磷酸盐矿物（鸟粪石、变水磷钾铀矿）的类似物。根据GOST R 52126 - 2003半动态试验确定了化合物的水解稳定性。确定了化合物中放射性核素的低浸出率，包括钚和镅的微分浸出率分别为3.5×10和5.3×10 g/(cm²∙天)。研究工作的结果表明，MKP化合物在固定LRW方面具有前景，并且可以成为一种结合了诸如胶结等技术易于实施的优点以及类似于玻璃状化合物的高物理和化学稳定性优点的替代材料。
