French Industrial Vitrification Plant: 30 Years Old and Still Innovating
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French Industrial Vitrification Plant: 30 Years Old and Still Innovating E. Chauvin1, C. Ladirat2, R. Do Quang1 1 AREVA NC, 1 Place Jean Millier, 92084 Paris La Defense, France 2 CEA, Valhro, BP 171, Batiment 208, 30207 Bagnols sur Ceze Cedex, France ABSTRACT In 2008, AREVA NC Industrial Vitrification of High-Level Liquid Waste blows out its 30th candle, with always two main objectives during all the time: containment of the long lived fission products and reduction of the final volume of waste. During all this time AREVA with the French Atomic Energy Commission (CEA) developed and use in their industrial installations a selection of borosilicate glass that have been demonstrated as the most suitable containment matrix for waste from spent nuclear fuel. Consistent and long-term R&D programs associated to industrial feed back from operation have enabled continuous improvement of the process: throughput and waste loading factor enhancement. The Vitrification Process used and currently implemented in the AREVA facilities will be described. INTRODUCTION Vitrification of high-level liquid waste is now an internationally recognized standard. Many countries such as the USA, Russia, United Kingdom, Germany, Belgium and Japan have already vitrified high level waste and several more countries are studying application of the vitrification technology. The first work on vitrification of radioactive waste began in France in 1957 at the Saclay nuclear center with early the selection by CEA (French Atomic Energy Commission) of: • Borosilicate glass as the most suitable containment matrix for waste from spent nuclear fuel. By the mid 60s, borosilicate glasses were selected for the vitrification of HLW solutions as the best compromise in terms of containment (leach resistance, thermal stability, resistance to irradiation), technological feasibility, and cost (via the volume reduction factor). The first high-level radioactive glass blocks, weighing 3 kg each and containing some 111 TBq, were fabricated at the Marcoule industrial site in 1965, in graphite crucible. Today, borosilicate glasses have become a worldwide standard and have been chosen for nearly all vitrification processes of HLW solutions. • Induction-heated vitrification technology: the metallic melter is joule heated by using electric inductors; the heating system is outside the metallic melter (melting pot) and thus independent from the melting pot; Not sensitive to the glass melting (no wear, no corrosion, no shorting); Not directly contaminated by High Active Level glass; Easy to start (even if the metallic melter is full or empty), to stop, to maintain or to replace.Induction technology development was conducted in parallel with glass formulation studies. The way from preliminary R&D choices to large scale industrial implementation is always the result of a combined approach which involves research, engineering and operating team, and also a judicious build up of results and experience. The design and operation of three industrial vitrification facilities with high re
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