Numerical Modeling and Aging Analysis of a Joule‐Heated Ceramic Melter Used for Radioactive Waste Vitrification

ABSTRACT Nuclear fuel reprocessing focuses on recovering valuable materials from spent fuel and plays a crucial role in managing the closed nuclear fuel cycle. A significant by‐product of this process is high‐level liquid waste (HLLW), known for its intense radioactivity and potential environmental risks. Effective treatment, conditioning, and disposal of HLLW are essential. Notable equipment in this field is a Joule‐heated ceramic melter (JHCM), which utilizes high‐temperature ceramic melters to vitrify radioactive waste, converting it into a stable glass matrix suitable for long‐term storage. Developing a numerical model for a JHCM offers valuable insights into its design, operation, and performance evaluation. This paper proposes developing a numerical model, incorporating various physical phenomena within a JHCM such as Joule heating, conduction, convection, and fluid flow along with the geometrical arrangement of the insulation and refractory layers of a JHCM and validating it using benchmark JHCM data and also with JHCM temperature data from a waste vitrification plant. Using electrical current, temperature, and velocity distributions, the melter's performance and operation are studied in preheating and heating phases. The melter's performance parameters are defined and evaluated using a numerical model. Further, the model includes suitable time‐dependent property variations of different JHCM materials to evaluate the performance variation for a period of 5 years of operation. This model can be utilized for optimizing the design, operation, and performance of JHCMs meant for nuclear waste management.