Improvement of the Power Supply Technical Scheme for the Electric Melter System in High‐Level Radioactive Liquid Waste Vitrification

The electric melter system is a critical component in the high‐level radioactive liquid waste (HLLW) vitrification process, with a safety classification of radiochemical safety (RS) level. At an operational site, the electric melter system is designed to be powered by an emergency power supply system, and manual switching of the power supply is employed to address power failure incidents. During long‐term operation, the operating company identified several critical issues associated with the manual power switching process: excessive workload for operators, low operational efficiency, and poor timeliness in power restoration. In this study, rigorous theoretical analyses were conducted to diagnose the root causes of the aforementioned problems. Subsequently, two distinct and innovative electrical technical improvement schemes were proposed, each accompanied by detailed operational procedures for implementation and a reliable execution framework to ensure on‐site applicability. A comprehensive evaluation was then performed on both schemes, considering factors such as economy, reliability, and on‐site implementability. The optimally selected scheme was successfully implemented at the operational site, and its performance was further verified through subsequent HLLW vitrification operation cycles. The results demonstrate that the proposed technical improvement scheme fully resolves the practical challenges and demands of the operating company, achieving the expected objectives with excellent effectiveness. Furthermore, the implementation of the proposed technical improvement scheme has mitigated the potential risks induced by operational delays or intricate procedures, enhanced the certainty of power supply restoration under accident conditions, and thus exerted a crucial role in safeguarding the stable operation of the HLLW vitrification process. Another prominent contribution of this study lies in the provision of electrical single‐line diagrams derived from the proposed technical improvement schemes. These diagrams can serve as a standardized design template and provide crucial references for the power supply system design of new HLLW vitrification projects.