Nuclear charge waste from

After the separation of the actinides from the high-level waste, it is desirable to remove certain other fission products from the nuclear wastes. Some Cs and Sr are low-charged cations that react well with macro-cyclic ligands (e.g., crown ethers, calixarenes). Research to synthesize and investigate the properties of macrocyclic ligands for application in nuclear waste treatment has been an active effort internationally. Some of the results obtained are discussed in section 12.7. 

Translated into zeolite terms this means that when the charge on the framework is high (low Si/Al ratio) the first term dominates and the zeolite shows selectivity for small highly hydrated cations. An example of this is the use of LTA as a detergent builder (see later). For zeolites with high Si/Al ratios in their frameworks the second term is influential and they will prefer larger cations which are less hydrated, such as in the use of clinoptilolite to scavenge radioactive Cs from aqueous nuclear waste. 

Since UO2 is the most common uranium oxide found in nuclear fuels, uranium extraction from UO2 is indispensable in the nuclear fuel reprocessing and uranium waste treatment. From solid UO2, however, uranium extraction is not possible with this method because TTA nor TBP form complexes with UO2 directly. If we introduce acid homogeneously in SF-CO2, we can expect UO2 dissolution and conversion into U02, which can be complexed with TBP by the charge neutralization as TBP2U02(N03)2. For example, concentrated nitric acid is widely used to dissolve UO2 in aqueous solution forming U02(N03)2. 

It also can be used for the low-waste, environmentally friendly, clean and safe production of especially pure materials ion-exchange resins of nuclear cleanliness low-waste extraction of components from the solid materials (for instance, the extraction of platinum and palladium from the spent catalysts) and deactivation of materials and equipment of radiochemical enterprises [10, 11]. The industrial Soxhlet extractor and evaporator were made from steel covered with acid-resistant Ftoroplast coating sheets. The charge volume of the industrial Soxhlet apparatus could be significantly increased up to 16 cubic meters using stainless steel apparatus with acid-resistant ftoroplast coating sheets. 

Some insight into the methodological challenges in theoretical studies of f elements can already be gathered from looking at the uranyl double cation UO l which is a closed-shell molecule important in the treatment of nuclear waste. In this molecule the uranium atom has formal oxidation state + W, but from projection analysis [55] at the HF level we find a charge of -1-2.94 and configuration 5/ - 7/ of the uranium atom in the molecule. 

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