Abstract
The numerous constraints associated with the management of Intermediate and High-Level Waste (ILW & HLW), with potentially complex physical-chemical compositions, led to investigate the implementation of in-situ conditioning treatment able to produce waste packages compliant with existing storage and disposal routes or on-site interim storage facilities. The issues involved in the management of this kind of waste can vary widely, and thermal treatment solutions seems logical given that these offer multiple advantages. Vitrification processes enable volume reduction, chemical stabilization of the waste, and efficient containment of radioelements in a glassy or glass-ceramic matrix. Moreover, vitrification processes have proven their adaptability to intermediate and high-level waste and can be flexible enough to accommodate a varied waste stream.
In this context, the DEM&MELT In-Can process has been developed to match the requirements and constraints of challenging ILW and HLW. DEM&MELT is an innovative compact vitrification tool that can deal with a wide range of nuclear waste streams with different compositions and forms such as slurries, deposits, liquid effluents, ashes, adsorbents... DEM&MELT is flexible enough to accommodate uncertainties in waste composition and has been developed with a modular design adaptable to nuclear operators’ needs. The process allows a significant volume reduction in addition to safe radionuclides containment with moderate investments and operating costs.
A major milestone was achieved with the commissioning of a full-scale pilot in CEA Marcoule site and the implementation of several demonstration tests on various waste streams. The tests results confirm that the technology can achieve high waste loading and provides durable containment of the radionuclides as well as stabilization of the waste. The tests carried out also confirmed the simplicity, robustness, and versatility of the process.
This paper presents some results of demonstration tests performed on various waste with an emphasis on the process parameters, the waste loading achieved, the wasteform properties and the radionuclides volatility. The up-scaling methodology implemented to demonstrate the applicability of the DEM&MELT process to an identified waste, from laboratory scale tests through full-scale pilot tests up to the industrial design definition is also highlighted.
