Application of plasma shield technology to the reduction, treatment and disposal of hazardous organic and/or mixed wastes with actinide recovery

Two broad classes of thermal plasma reactors are currently in widespread use: the direct current (dc) arc jet systems and the radio frequency (rf) inductively coupled system. Los Alamos has improved upon the basic rf plasma tube design using the concept of a transformer. The unique feature of the Los Alamos tube is a segmented, cooled, internal radiation shield. Several heavy-walled, water-cooled copper fingers are inserted inside the quartz mantle. These fingers couple power from the surrounding rf coil to the contained plasma, while their chevron cross section is such that they overlap each other and prevent ultraviolet radiation from impinging upon the surrounding quartz. This allows the Los Alamos torch to be operated at temperatures as high as 15,000 K, whereas conventional torches tend to melt down at 12,000 K. The shield also eliminates the arcing between the quartz mantle and the rf coil that typically occurs due to the ionization of the surrounding air from ultraviolet radiation. The Los Alamos shielded plasma torch routinely achieves temperatures exceeding 10,000 K and electron densities of 1016/cm3 when operated continuously at one atm. of argon. These highly energetic conditions are sufficient to dissociate most chemical compounds into their constituent atoms. Based upon these characteristics, Los Alamos is currently investigating the application of the shielded plasma torch technology to the destruction of organic and mixed hazardous wastes, as well as the direct production of actinide metals from the halides and oxides, without the cogeneration of contaminated wastes