Microwave treatment of radioactive waste
    With nuclear and radiation technology in our production and increasing life applications , radioactive waste has become an unavoidable byproduct , it needs to be stabilized in order to deal with long-term storage , reducing the harm to humans . Vitrification of radioactive material is treated as a good way to waste it by mixing with silica or other additives , and then heated to molten state , the molten material cooling state after the formation of the glassy substance. Glass glassy material formed by the radioactive substance sealed , thereby reducing the ability of the dispersion . The glass forming substance than other forms of waste has the following advantages :
    ( 1 ) forming a glassy material with excellent mechanical properties and thermal stability ;
( 2 ) Glass can handle a diverse range of pollutants , without affecting the final quality of the formation of the glassy material
( 3 ) Glass can handle a large number of organic and inorganic contaminants ;
    ( 4 ) In most cases , the glass can reduce the volume of pollutants , thereby reducing disposal costs ;
    ( 5 ) Glass waste to form a stable form ;
    ( 6 ) even if mechanical damage , glassy substance is still able to maintain its original characteristics .
    Radioactive waste vitrification methods include microwave heating , Joule heating , plasma heating , resistance heating , induction heating, electric arc heating , rotary incinerator heating. Microwave heating is a newer and more cost-effective method, with its unique advantages. The main advantage of microwave treatment is delivered directly to the energy of the radioactive waste to be treated , without electrodes , refractory liner and the auxiliary devices , saving investment. In addition , the microwave heating method of heating than a higher heating rate, which in the heating performance of poor thermal conductivity performance of the most prominent waste . Because microwave melting is in a closed container for storage , and therefore not affect the viscosity of pollutant control factors , which means that the glassy material can wrap more waste , thereby reducing the volume of waste storage facilities . Microwave heating has a wider adaptability, able to handle a large volume of many types of waste , and the equipment is easy to control maintenance.
    Microwave processing apparatus generally includes 6 kW 2. 45 GHz microwave generating body of the waveguide , tuner, resonant cavity radiation operation box , rotary , screw feeder , separate cooler. In addition to the feed chamber is internal radiation control box , the other devices are installed on the operation of radiation outside the box , so not only reduces the device is the possibility of radioactive contamination , but also more conducive to action. Intermittent operation processing means can also be run continuously . Intermittent operation generally has the following steps : Waste broken ; broken waste glass reagent mixture into the insulated container ( wrapped with fiber insulation to reduce heat loss during processing ) in ; insulated container into feed chamber is heated ( heated to the desired temperature required to maintain a certain period of time in order to ensure adequate heating and reaction complete ) ; material cooled final disposal .
    Many scholars have right now at the disposal of radioactive waste microwave applications conducted in-depth research . Petersen microwave laboratory processing transuranic sludge showed that 70% of the sludge volume reduction , waste load of 60%; Komatso and others in the incineration ash is added 137Cs, 60Co and 54Mn with 6 kW2. 45GHz microwave treatment, experimental results show that all of the 60Co, 54Mn and 137Cs completely wrapped in the final part of the glassy product , another part of the 137 Cs volatile , and can be reduced by adding B2O3 volatilization of 137Cs ; Morrell and others with microwave treatment of waste water containing radioactive substances , and 137Cs sealed in glass bricks , testing showed 99.99% of 137Cs and stable encapsulated in glass brick .