Waste2Glass is a company created and owned by Cyclife EDF and Veolia Nuclear Solutions. It is dedicated to the development of the GeoMelt® vitrification technology in Europe.
Technologically Enhanced Naturally Occuring Radioactive Material waste issues from several human industrial activities based on mining including, for example, Zircon and Rare Earth production. Due to the industrial process, the NORM present in the ore are commonly concentrated and more dispersible, resulting in hazard potential for humans and the environment. In addition, these wastes usually contain high concentrations of chemicals such as chlorides or nitrates. Therefore, TENORM are classified as nuclear hazardous waste.
TENORM contain very long lasting radionuclides Thorium and Uranium. During decay, these nuclides produce Radium that itself generates Radon Gas. The radium proportion in the radionuclides varies significantly regarding the origin of the waste and has a great influence on the nuclear hazard. Waiting for the radioactive decay is not an option for TENORM.
TENORM are common in large volumes in countries where the nuclear industry is developed, including France and the USA. In France, two main categories of TENORM waste are distinguished; the one with the higher content ratio of Radium is denominated “Radifère’. The volume of that category in France is estimated to be 50 000 cubic meters (65 000 cubic yards) by 2040, most of it already produced by 2022.
TENORM requires long-term storage management in drastically simpler and cheaper conditions compared to other long-lived waste, such as fuels. There is today no solution in France for the long-term storage of these wastes. The ANDRA, French disposal operator, plans to store it in a near surface disposal utility currently under development (FA-VL). This disposal is scheduled in a clay layer at ‘Vendeuvre-Soulaines’ location. The repository, dedicated to ‘low activity-long life’ waste would accept not only TENORM but also other wastes such as graphite and bitumen based mixes. Nevertheless, these categories are heterogeneous with radionuclides, activity and physico-chemical parameters different from one family to the other. In addition, the overall volume of the repository would not be large enough for the full amount of targeted waste. So, in the National Plan for management of radioactive waste 2022-2026, the French state asked the ANDRA to optimize the global strategy for the ‘low activity-long life’ wastes, identify as far as necessary new options for some wastes and study the filling of the ‘Vendeuvre-soulaines’ future repository.
Waste2Glass considers that the GeoMelt® vitrification process applied to TENORM is a good opportunity to contribute to this optimization because:
• It commonly results in a reduction of the volume of the waste. TENORM are stored in drums or stacks. Using the GeoMelt® ‘In Container ‘Vitrification’ option, allows an increase of the overall density even if vitrification agent has to be added. In addition, the resulting material is easier to handle.
• The associated radiological hazards are greatly reduced. The vitrification process transforms a dispersible and leachable waste into a dense and monolithic block. Thus, the radiation levels and contamination risks are reduced and controlled in normal and accidental conditions. The release of Radon gas is reduced because of the retention of the gas in the solid during it’s lifetime.
• The chemical hazard is usually reduced. The thermal treatment can destroy or convert several toxic species and reduce the potential mobility of the nuclides in the clay layer.
• The physico-chemical retention properties of the glass-like structure are very long lasting and well adapted to the Radium activity (half-life 1602 years).
As a consequence the GeoMelt® vitrification process applied to TENORM can dramatically reduce the constraints applied to the repository design for these wastes and thus allow easier, safer, larger and cheaper long term storage of the TENORM waste. It could also improve the confidence of the public for the development of the repository. It could also divert some of the TENORM to other sites than ‘Vendeuvre-Soulaines’, typically landfill accepting Very Low Level Nuclear Wastes.
In 2021, Waste2Glass designed a project named ‘Rad2Glass’ to make a demonstration of this opportunity. The project started in March 2022 and will be completed at the end of 2023. It includes theoretical and experimental proofs of concept at bench-scale and engineering scales. The project is managed together with French TENORM owning companies interested in the results. The project is supported by the French state via the ‘Banque Publique d’Investissement’.
The results obtained up to now with that project for the waste in simulated conditions are encouraging:
-A mass integration rate of waste in the glass material has been obtained at more than 50% and up to 80% for a priority waste.
-The accelerated ageing of the glass confirms a containment efficiency in accordance with the expected requests of the safety case of the repository, at least in the absence of concrete.
The work is today in progress in several other aspects:
-Radon Gas retention in the vitrified product measurement,
-Design of the engineering pilot tests with waste simulants (500 kg vitrified material),
-Environmental and Economical performance assessments,
-Extension of the studies to other wastes streams,
Regarding the results, industrial facilities could start in the following years the vitrification of TENORM in France, in association with the waste owners.