Dewatering verification and performance analysis of High-Density Polyethylene High Integrity Container (HDPE-HIC) loading and dewatering system

This study presents a comprehensive analysis of the dewatering verification and performance of a High-Density Polyethylene High Integrity Container (HDPE-HIC) loading and dewatering system for radioactive waste management. While HDPE-HIC technology is internationally established for storing spent ion exchange resins from nuclear power plants, a significant research gap remains in the development of efficient and well-characterized dewatering processes that can consistently achieve the strict disposal requirement of less than 1% free water content, particularly for domestically designed systems. Furthermore, the mechanistic understanding of key process parameters, such as the optimal resin-to-water ratio and the dynamics of water removal, is insufficiently documented. This research addresses these gaps through the development and detailed verification of a localized dewatering system. Laboratory experiments and system tests demonstrated that the system achieved a free water content of less than 0.8% and completed dewatering within 1.33 days, exceeding the standard requirements. The relationship between resin-to-water ratio and dewatering efficiency was quantified, identifying a 60:40 ratio as optimal. Water absorption characteristics were consistently measured across sample sizes, showing approximately 50.6% free water and 3.9% bound water content. The volume reduction dynamics during dewatering were also analyzed, providing critical insights for system optimization. This work not only validates an efficient localized solution but also enhances the fundamental understanding of dewatering mechanisms, contributing significantly to the advancement and self-reliance in radioactive waste management technology.