Apparatus and methods for treatment of radioactive organic waste

Abstract

Treatment of radioactive waste comprising organic compounds, and sulfur-containing compounds and/or halogen-containing compounds. An apparatus comprises a reaction vessel comprising a filter for carrying out thermal treatment of the waste and a thermal oxidizer. Utilizing co-reactants to reduce gas phase sulfur and halogen from treatment of wastes.

We claim: 
     
         1 . An apparatus for the treatment of radioactive waste comprising organic compounds, and sulfur-containing compounds and/or halogen-containing compounds, the apparatus comprising:
 (a) a reaction vessel comprising a filter for carrying out thermal treatment of the waste; and   (b) a thermal oxidizer.   
     
     
         2 . The apparatus of  claim 1 , wherein the apparatus further comprises:
 (c) an adsorption vessel comprising one or more types of adsorbent media for adsorbing sulfur-containing compounds and/or halogen-containing compounds after treatment of the waste by the reaction vessel.   
     
     
         3 . The apparatus of  claim 1 , wherein the reaction vessel comprising a filter further comprises a bed in the lower portion of the reaction vessel comprising a filter. 
     
     
         4 . The apparatus of  claim 3 , wherein the bed in the reaction vessel comprising a filter comprises the waste, one or more co-reactants and optionally, inert bed media. 
     
     
         5 . The apparatus of  claim 4 , wherein the bed is partially fluidized or jetted. 
     
     
         6 . The apparatus of  claim 1 , wherein the apparatus further comprises a process reaction vessel upstream of the reaction vessel comprising a filter. 
     
     
         7 . The apparatus of  claim 6 , wherein the process reaction vessel further comprises a bed in the lower portion of the process reaction vessel. 
     
     
         8 . The apparatus of  claim 7 , wherein the bed in the process reaction vessel comprises the waste, one or more co-reactants and optionally, inert bed media. 
     
     
         9 . The apparatus of  claim 1 , wherein the temperature of the reaction vessel comprising a filter is below the temperature at which the sulfur-containing compounds and/or halogen-containing compounds volatilize. 
     
     
         10 . The apparatus of  claim 1 , wherein the temperature of the process reaction vessel is below the temperature at which the sulfur-containing compounds and/or halogen-containing compounds volatilize. 
     
     
         11 . The apparatus of  claim 2 , wherein the adsorbent media comprises one or more types of adsorbent media selected from the group consisting of: compounds that adsorb sulfur-containing compounds and produces a sulfate compound; compounds that adsorb sulfur-containing compounds and produces a metal sulfide, alkaline earth sulfide, or another sulfide; metal or alkaline earth adsorbents; iron, nickel or zinc metals; metal oxides; and Al(OH) 3 . 
     
     
         12 . A method for treating radioactive waste comprising organic compounds, and sulfur-containing compounds and/or halogen-containing compounds, the method comprising:
 (a) adding radioactive waste comprising organic compounds, and sulfur-containing compounds and/or halogen-containing compounds; and one or more co-reactants to a reaction vessel comprising a filter to form a bed in the lower portion of the reaction vessel comprising a filter;   (b) heating the reaction vessel comprising a filter to a temperature of in the range of about 250° C. to about 1050° C. to form pyrolyzed radioactive waste residues and waste gases;   (c) agitating, partially fluidizing or jetting the bed of the reaction vessel comprising a filter;   (d) optionally, adding a reactive gas to the reaction vessel to gasify carbon in the pyrolyzed waste residues;   (e) removing pyrolyzed radioactive waste residues from the reaction vessel comprising a filter for disposal; and   (f) transferring the waste gases from the reaction vessel comprising a filter to a thermal oxidizer for combustion;   wherein the reaction vessel comprising a filter may optionally be heated to a temperature of in the range of about 250° C. to about 1050° C. prior to step (a).   
     
     
         13 . The method of  claim 12 , wherein step (b) may be carried out prior to step (a). 
     
     
         14 . The method of  claim 12 , wherein step (d) comprises adding a reactive gas to the reaction vessel comprising a filter to gasify carbon in the pyrolyzed waste residues. 
     
     
         15 . The method of  claim 14 , wherein the step of adding a reactive gas to gasify carbon in the pyrolyzed waste residues is carried out at a temperature below that which the sulfur-containing compounds and/or halogen-containing compounds volatilize. 
     
     
         16 . The method of  claim 12 , wherein the one or more co-reactants is for treatment of waste comprising sulfur-containing compounds under reducing conditions and is selected from the group consisting of: compounds of calcium; zinc; iron; nickel; tin; alkali metals, such as sodium, potassium and lithium; alkaline earth metals, such as magnesium and barium; aluminum; bismuth; manganese; molybdenum; phosphorus; silicon; silver; strontium; tin; calcium silicates; commercial H 2 S adsorbents; or other compounds which can be reacted with sulfur-containing compounds to form stable sulfides and/or H 2 S; and mixtures thereof. 
     
     
         17 . The method of  claim 12 , wherein the one or more co-reactants is for treatment of waste comprising sulfur-containing compounds under oxidizing conditions and is selected from the group consisting of: compounds of calcium, magnesium, barium, sodium, potassium, lithium, aluminum, iron, nickel, manganese, clays, calcium silicates, or other compounds which can be reacted with sulfur-containing compounds to form stable sulfate and sulfite compounds with sulfur oxides (SO 4   2−  and SO 3   2− ), and mixtures thereof. 
     
     
         18 . The method of  claim 12 , wherein the waste and the one or more co-reactants are heated to a temperature of about 884° C. or less to prevent decomposition or melting of sodium sulfate. 
     
     
         19 . The method of  claim 12 , wherein the waste and the one or more co-reactants are heated to a temperature of about 602° C. or less to prevent decomposition of Fe 2 S. 
     
     
         20 . The method of  claim 12 , wherein the waste and the one or more co-reactants are heated to a temperature of about 1050° C. or less to prevent decomposition of calcium sulfide or zinc sulfide. 
     
     
         21 . The method of  claim 12 , wherein the one or more co-reactants is for treatment of waste comprising halogen-containing compounds and is selected from the group consisting of: compounds of calcium, zinc, iron, nickel, sodium, potassium, lithium, aluminum, magnesium, barium, bismuth, cerium, cobalt, manganese, molybdenum, silver, tin, titanium, zirconium, clays, calcium silicates, or other compounds which can be reacted with halogen-containing compounds to form salts or stable, non-volatile halide compounds, and mixtures thereof. 
     
     
         22 . The method of  claim 12 , wherein the waste and the one or more co-reactants are heated to a temperature of about 801° C. or less to prevent decomposition or melting of sodium chloride. 
     
     
         23 . The method of  claim 12 , wherein the bed does not contain inert bed media. 
     
     
         24 . The method of  claim 12 , wherein the method further comprises transferring the waste gases to an adsorption vessel comprising adsorbent for adsorbing sulfur-containing compounds and/or halogen-containing compounds prior to transferring the waste gases to a thermal oxidizer for combustion. 
     
     
         25 . The method of  claim 24 , wherein the method further comprises transferring the waste gases to an adsorption vessel comprising adsorbent for adsorbing sulfur-containing compounds and/or halogen-containing compounds prior to transferring the waste gases to a thermal oxidizer for combustion. 
     
     
         26 . A method for treating radioactive waste comprising organic compounds, and sulfur-containing compounds and/or halogen-containing compounds, the method comprising:
 (a) adding radioactive waste comprising organic compounds, and sulfur-containing compounds and/or halogen-containing compounds; and one or more co-reactants to a process reaction vessel to form a bed in the lower portion of the process reaction vessel;   (b) heating the process reaction vessel to a temperature in the range of about 35° C. to about 1050° C.;   (c) agitating, partially fluidizing or jetting the bed while maintaining the temperature of the process reaction vessel in the range of about 35° C. to about 1050° C. to form fully or partially pyrolyzed radioactive waste residues and waste gases;   (d) transferring the fully or partially pyrolyzed radioactive waste residues and waste gases from the process reaction vessel to a reaction vessel comprising a filter to form a bed in the lower portion of the reaction vessel comprising a filter;   (e) heating the reaction vessel comprising a filter to a temperature in the range of about 250° C. to about 1050° C.;   (f) agitating, partially fluidizing or jetting the bed of the reaction vessel comprising a filter while maintaining the temperature of the reaction vessel comprising a filter in the range of about 250° C. to about 1050° C. to form fully or partially pyrolyzed radioactive waste residues and waste gases;   (g) optionally, adding a reactive gas to the reaction vessel comprising a filter to gasify carbon in the partially pyrolyzed waste residues;   (h) removing the fully pyrolyzed radioactive waste residues from the reaction vessel comprising a filter for disposal; and   (i) transferring the waste gases from the reaction vessel comprising a filter to a thermal oxidizer for combustion;   wherein the process reaction vessel may optionally be heated to a temperature in the range of about 35° C. to about 1050° C. prior to step (a); and wherein the reaction vessel comprising a filter may optionally be to heated to a temperature in the range of about 250° C. to about 1050° C. prior to step (d).   
     
     
         27 . The method of  claim 26 , wherein step (b) may be carried out prior to step (a). 
     
     
         28 . The method of  claim 26 , wherein step (e) may be carried out prior to step (d). 
     
     
         29 . The method of  claim 26 , wherein the process reaction vessel is heated to a temperature in the range of about 250° C. to about 1050° C. 
     
     
         30 . The method of  claim 26 , further comprising adding a reactive gas to the reaction vessel comprising a filter in step (g) to gasify carbon in the pyrolyzed waste residues. 
     
     
         31 . The method of  claim 30 , wherein the step of adding a reactive gas to gasify carbon in the pyrolyzed waste residues is carried out at a temperature below that which the sulfur-containing compounds and/or halogen-containing compounds volatilize. 
     
     
         32 . The method of  claim 26 , wherein the one or more co-reactants is for treatment of waste comprising sulfur-containing compounds under reducing conditions and is selected from the group consisting of: compounds of calcium; zinc; iron; nickel; tin; alkali metals, such as sodium, potassium and lithium; alkaline earth metals, such as magnesium and barium; aluminum; bismuth; manganese; molybdenum; phosphorus; silicon; silver; strontium; tin; calcium silicates; commercial H 2 S adsorbents; or other compounds which can be reacted with sulfur-containing compounds to form stable sulfides and/or H 2 S; and mixtures thereof. 
     
     
         33 . The method of  claim 26 , wherein the one or more co-reactants is for treatment of waste comprising sulfur-containing compounds under oxidizing conditions and is selected from the group consisting of: compounds of calcium, magnesium, barium, sodium, potassium, lithium, aluminum, iron, nickel, manganese, clays, calcium silicates, or other compounds which can be reacted with sulfur-containing compounds to form stable sulfate and sulfite compounds with sulfur oxides (SO 4   2−  and SO 3   2− ), and mixtures thereof. 
     
     
         34 . The method of  claim 26 , wherein the waste and the one or more co-reactants are heated to a temperature of about 884° C. or less to prevent decomposition or melting of sodium sulfate. 
     
     
         35 . The method of  claim 26 , wherein the waste and the one or more co-reactants are heated to a temperature of about 602° C. or less to prevent decomposition of Fe 2 S. 
     
     
         36 . The method of  claim 26 , wherein the waste and the one or more co-reactants are heated to a temperature of about 1050° C. or less to prevent decomposition of calcium sulfide or zinc sulfide. 
     
     
         37 . The method of  claim 26 , wherein the one or more co-reactants is for treatment of waste comprising halogen-containing compounds and is selected from the group consisting of: compounds of calcium, zinc, iron, nickel, sodium, potassium, lithium, aluminum, magnesium, barium, bismuth, cerium, cobalt, manganese, molybdenum, silver, tin, titanium, zirconium, clays, calcium silicates, or other compounds which can be reacted with halogen-containing compounds to form salts or stable, non-volatile halide compounds, and mixtures thereof. 
     
     
         38 . The method of  claim 26 , wherein the waste and the one or more co-reactants are heated to a temperature of about 801° C. or less to prevent decomposition or melting of sodium chloride. 
     
     
         39 . The method of  claim 26 , wherein the bed does not contain inert bed media.