模拟不可燃放射性废物等离子体熔融处理试验研究

Experimental Study on Plasma Melting Treatment of Simulated Non-Combustible Radioactive Waste

在自制的等离子体熔融试验台架上对玻璃纤维、混凝土、土壤的单体玻璃固化配方及三元混合废物玻璃固化配方开展等离子体熔融处理和同位素示踪实验。四种样品在1 100~1 300℃条件下熔融1 h均可得到玻璃固化体,经检测,玻璃固化体的密度、抗浸出性能以及机械性能均满足放射性废物玻璃固化体性能要求。示踪实验结果表明,等离子体熔融系统对示踪元素Co、Cs和Sr有较高截留率,且玻璃固化体对Co和Sr的固化能力较高、对Cs固化能力相对较低。在工程应用中,建议在熔融炉系统前端增设造粒等预处理系统,减少物料直接进入烟气净化系统的比例,以提高物料固化效率。

The melting treatment and isotopic tracing experiments were carried out on a self-designed plasma bench melting test with glass solidification formulas of single waste as well as mixed waste of glass fiber, concrete and soil. After melting at 1 100-1 300 ℃ for 1 h, all the four samples were turned into glass waste-forms. The density, leaching and mechanical performance of resultant glass waste-forms were tested, showing the comparable requirement with the radioactive waste glasses. The results of the tracer experiment show that the plasma melting system has high interception rate for the tracer elements Co, Cs and Sr. In addition, the glass waste-forms has higher curing capacity for Co and Sr, but lower for Cs. In engineering application, it is suggested to add a pretreatment system such as granulation at the front of the melting furnace system to reduce the proportion of material directly entering the flue gas purification system and improve the solidified efficiency of the materials.