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Two experiments on the vitrification of a surrogate for the wastes from the Savannah River plant (USA) have been performed on a cold-crucible (inner diameter 216 mm) induction-melting bench facility at the Moscow Scientific and Industrial Association Radon (1.76 MHz, 60 kW). To obtain borosilicate glasses with two compositions containing 45 mass % oxides of the wastes (computed) a slurry with moisture content about 60 mass % and a mixture of reagents as the glass-forming additives gave a mass velocity of the slip 8 kg/h on average, glass output about 2 kg/h, and specific glass product rate about 47 kg/(m 2 ⋅h). The specific energy consumption was 20 kW⋅h/kg. It was shown that the mass velocity of the slip can be increased to 18 kg/h. Switching to glass-forming additives consisting of the special borosilicate frit-200 and -320 and lowering the water content in the slurry to 25-30 mass % increases the productivity of the process by 15-35%. The specific glass production rate reaches 100 kg/(m 2 ⋅h). The glasses produced contained a small quantity of a magnetitic spinel phase.Vitrification is now the best developed method of solidifying liquid radioactive wastes, especially high-level wastes. High-level wastes are vitrified commercially in metal induction melters at the average frequency (10-50 kHz) or joule-heated ceramic melters. One of the new methods being developed most intensively in France and our country is induction melting in a cold crucible at frequencies above 300 kHz, for example, in the Moscow Scientific and Industrial Association Radon facility for vitrifying medium-level wastes at 1760 kHz. This technology is of interest because it has certain advantages, such as a higher specific capacity and no contact between the melt and the refractories and electrodes, which increases the life span and operational reliability of the melter and allows much smaller dimensions thereby facilitating disassembly and removal after the melter is removed from operation [1,2].The experiments described in the present paper on the vitrification of surrogates of high-level wastes from one of the facilities of the US Department of Energy were performed within the framework of a signed contract. The objective of the present paper is to estimate the technological parameters of cold-crucible induction melting of a charge containing a surrogate of one form of high-level wastes (SB2) from the Savannah River facility and to determine the structure and properties of the glasses in order to compare them with those obtained in the USA using a ceramic melter.

Experiments on vitrifying a surrogate for SB2 pulp from the Savannah River facility (USA) in a cold crucible with inner diameter 418 mm in a commercial facility for vitrifying medium-level wastes at the Moscow Scientific and Industrial Association Radon are performed. Borosilicate glass materials, containing 50 mass % oxides of the wastes, including a magnetitic spinel phase in amounts not exceeding 15 vol. %, are obtained. The maximum mass average velocity of the slurry load and the melt output reach 40 and 16 kg/h, respectively. This corresponds to maximum specific vitrified wastes production capacity 2830 kg/(m 2 ⋅day). The specific energy consumption for obtaining the glass product is about10 kW⋅h/kg, which is approximately half the level for reprocessing slurries in crucibles with half the diameter. The chemical stability of the glass materials is 10-50 times higher than that of the materials made from glasses recommended by the US Environmental Protection Agency.Induction melting in a cold crucible is a promising method for vitrifying radioactive wastes. A process for vitrifying medium-level wastes has been implemented on a commercial scale at the Moscow Scientific and Industrial Association Radon [1]. Experiments are being conducted on vitrifying surrogates for high-level wastes, primarily from the tanks at the Savannah River facility (SB2 pulps) [2][3][4][5]. The present article describes the experimental results obtained on the vitrification of slurries with frit-320 as an additive and waste oxides in amounts up to 50 mass % in the glass in a commercial-size cold crucible.Experimental Part. The technological scheme of the facility and the construction of individual units and apparatus are described in detail in [1]. A new, cylindrical, cold crucible (Fig. 1a), covered with a layer of fiberglass fabric to prevent leakage of the slurry (Fig. 1b) and equipped with a water cooled pouring device (Fig. 1c), was placed inside a box in a setup consisting of three process streams. The cold crucible, manufactured from 12 mm in diameter and 2 mm thick corrosion resistance steel tubes, had an inner diameter of 418 mm and a height of 860 mm. A VChG-8-160/1.76 rf generator with ac power 160 kW and working frequency 1.76 MHz supplied electric power. A peristaltic pump loaded the slurry from an intermediate holding tank. To make waste reprocessing more cost-effective, the content of waste oxides in the glass was increased to

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