Application of Plasma-Based Mass Separation for High-Level Radioactive Waste Remediation

Abstract

Spent fuel from nuclear power plants is considered the world's most toxic element, with 3.4% of fission products mass contributing to over 99.8% of the radioactivity. In the case of liquid high- level radioactive waste (HLRW) from spent fuel reprocessing, 0.7% of fission product mass contributes to 99.7% of the radioactivity. About 98.9% of the mass is bulk or non-radioactive elements. A separation mechanism on the mass categories bulk elements (1-60 amu), fission products (980-140 amu) and actinides (> 200 amu) presents a unique opportunity in managing HLRW for the long term with a considerable cost reduction. A thermal plasma-based separation system incorporating plasma torches and a separation chamber can separate HLRW into low- resolution mass groups. A single-phase plasma mass separation can replace a multi-phase chemical separation and residual waste. A mass separation system can operate under atmospheric pressure by utilizing a cross-electric and magnetic field and radiofrequency inductively coupled plasma (RF-ICP). Initial simulation with noble gas RF-ICP demonstrates a mass separation effect. Further analysis of the system is necessary before attempting to operate with the complex characteristics of HLRW.