# US 9,040,014 B2 · Graphite thermal decontamination with reducing gases > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,040,014 B2 - Document ID: US9040014B2 - Status: Granted - Kind: B2 - Application number: 13/278,786 - Filed: 2011-10-21 - Published: 2013-04-25 - Granted: 2015-05-26 - Earliest claimed: 2011-10-21 - Assignees: Electricite de France - Applicants: J. Bradley Mason; Thomas Brown; Sahar Torabzadeh; Jonathan Olander - Inventors: J. Bradley Mason; Thomas Brown; Sahar Torabzadeh; Jonathan Olander - Web page: https://patentgrep.com/patent/US9040014B2 ## CPC - B01D 59/02: Separation by phase transition - G21F 9/02: Treating gases - G21F 9/30: Processing (separating different isotopes of the same chemical element B01D59/00) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - G21F: PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR (radiation protection by pharmaceutical means A61K8/00, A61Q17/04; in cosmonautic vehicles B64G1/54; combined with a reactor G21C11/00; combined with X-ray tubes H01J35/16; combined with X-ray apparatus H05G1/02) ## Abstract Providing a roaster that operates at temperatures in the range of 800° Celsius to 2000° Celsius with inert, optional oxidizing and reducing gases to treat graphite contaminated with radionuclides including tritium, carbon-14, and chlorine-36. The combination of temperatures and gases allow for the removal of most to substantially all the carbon-14 within the graphite while substantially limiting gasifying the bulk graphite. ## Claims ### Claim 1 A method comprising the steps of: heating a roaster to a temperature between 800° Celsius to 2000° Celsius; introducing graphite contaminated with radionuclides into the roaster; introducing an inert gas into the roaster; introducing an oxidizing gas into the roaster so as to initiate an oxidation of said radionuclides; and removing volatilized radionuclides from the roaster; wherein a reducing gas is further introduced into the roaster in an amount between 2% and 20% of the total gas introduced so as to inhibit an oxidation of C-12 atoms of said graphite during the oxidation of said radionuclides. ### Claim 2 (depends on 1) The method of claim 1 wherein less than five (5) percent of the graphite is gasified. ### Claim 3 (depends on 1) The method of claim 1 wherein the temperature is between 1200° Celsius to 1500° Celsius. ### Claim 4 (depends on 1) The method of claim 1 wherein the radionuclides comprise carbon-14 and at least seventy (70) percent of the carbon-14 is removed from the graphite. ### Claim 5 (depends on 1) The method of claim 1 wherein the radionuclides comprise carbon-14 and at least ninety (90) percent of the carbon-14 is removed from the graphite. ### Claim 6 (depends on 1) The method of claim 1 wherein the inert gas comprises at least one of nitrogen, helium, and argon and the reducing gas comprises at least one of hydrogen, hydrazine, ammonia, and hydrocarbon vapor. ### Claim 7 (depends on 1) The method of claim 1 wherein the reducing gas comprises one or more reducing gases that can produce free hydrogen, ammonium, or organic vapor. ### Claim 8 (depends on 1) The method of claim 1 wherein the oxidizing gas comprises at least one of steam, carbon dioxide (CO2), nitrous oxide (N2O), oxygen (O2), air, alcohols (with OH groups), or other oxygenated vapors. ### Claim 9 (depends on 1) The method of claim 1 wherein the steps of introducing the inert gas into the roaster and introducing the reducing gas into the roaster comprise introducing the inert gas and the reducing case at a location near the bottom of the reactor and wherein the inert gas and the reducing gas flow through the graphite. ### Claim 10 (depends on 1) The method of claim 1 further comprising the step of reducing the size of the graphite prior to introducing the graphite into the roaster. ### Claim 11 (depends on 1) The method of claim 1 wherein the roaster comprises a vertically-oriented moving bed reactor and wherein the step of introducing graphite contaminated with radionuclides into the roaster comprises introducing the graphite near the top of the roaster and wherein the steps of introducing the inert gas into the roaster and introducing the reducing gas into the roaster comprise introducing the gases near the bottom of the roaster. ### Claim 12 (depends on 1) The method of claim 1 wherein the amount of reducing gas is between 2% and 10% of the total gas introduced. ### Claim 13 (depends on 1) The method of claim 1 wherein the amount of oxidizing gas is in the range of 1% to 10% of the total gas introduced. ### Claim 14 (depends on 2) The method of claim 2 wherein the radionuclides comprise carbon-14 and at least seventy (70) percent of the carbon-14 is removed from the graphite. ### Claim 15 (depends on 14) The method of claim 14 wherein at least ninety (90) percent of the carbon-14 is removed from the graphite.