Treatment of radioactive wastes by plasma incineration and vitrification for final disposal

• Published in: Journal of hazardous materials 1998-02, Vol.58 (1), p.207-220
• Main Authors: Tzeng, Chin-Ching, Kuo, Yung-Yen, Huang, Tsair-Fuh, Lin, Deng-Lain, Yu, Yuh-Jenq
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Plasma torch; Pollution; Radioactive waste; Radioactive wastes; Vitrification; Wastes
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/S0304-3894(97)00132-5

Thermal plasma technology takes the advantages to incinerate the combustible parts of radioactive wastes for volume reduction and to vitrify the noncombustible counter parts simultaneously into glassy slags with very low leaching rate. For developing the proper plasma processes to treat various waste forms, a crucible-type plasma melter and a 10 kg h −1 plasma furnace system are built at the Institute of Nuclear Energy Research (INER). Both systems are fired by the home-made 100 kW non-transferred plasma torches. The maximum operation temperatures of the small plasma melter, and the 10 kg h −1 plasma furnace are 1700°C and 1650°C, respectively. Glassy or ceramic slags with high quality are obtained from the processing of simulated radioactive wastes by plasma torch. The compressive strengths of these slags are greater than 800 kg cm −2, and the leaching indices of several elements are between 8 and 15, which are all greater than the ROC regulated values for waste forms (i.e. 15 kg cm −2 and 6). These promising results encourage INER to further develop plasma system with higher capacity and plasma processes for the treatment of low level radioactive wastes. Future efforts shall be concentrated on the studies of system reliability, secondary waste minimization and volatile radionuclides elimination in off-gas.