Simulated studies on optimization and characterization of feed and product of melter for safe disposal of high-level radioactive liquid waste

• Published in: Progress in nuclear energy (New series) 2020-01, Vol.118, p.103135, Article 103135
• Main Authors: Selvakumar, J., Rajasekaran, S., Chitra, S., Paul, Biplob
• Format: Article
• Language: English
• Subjects: Atomic emission spectroscopy; Boron oxides; Borosilicate glass; Composition; Differential scanning calorimetry; Durability; Emission analysis; Functional groups; Glass; High-level liquid waste; Inductively coupled plasma; Leaching; Liquid wastes; Optimization; Organic chemistry; Radioactivity; Reprocessing; Silicon dioxide; Simulation; Spectrometry; Thermal study; Thermodynamic properties; Titanium dioxide; Vitrification; Waste disposal
• ISSN: 0149-1970; 1878-4224
• DOI: 10.1016/j.pnucene.2019.103135

The elemental composition of actual High-level Liquid Waste (HLW) received from reprocessing plant was estimated from analysis of several samples by using Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). Based on the composition, the simulated waste (20–30 wt % based on oxide content) was prepared and vitrified in SiO2·Na2O·B2O3·TiO2·Fe2O3 glass system. Simulated Vitrified Waste Products (SVWPs) were characterized for their structural changes and relative thermal properties by using Infra-red (IR) spectrometry, X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) techniques. The measure of BO3, BO4, and Si−O−Si functional groups were found to be decisive in thermal and chemical durability of the products. Leach rate (LRNa) was found to be 10−5−10−6 g/cm2 day for ≤26% waste oxide (WO) loaded SVWPs. The relative increase in surface area by imparting 1 J of energy to the SVWPs was found to be