Patent Number: 
Section: claims

1. A method of capturing and immobilizing radioactive nuclei, the method comprising:flowing a gas stream through an exhaust apparatus comprising a metal fluorite-based inorganic material, the gas stream comprising a radioactive species; andremoving, from the gas stream, the radioactive species by adsorbing the radioactive species to the metal fluorite-based inorganic material of the exhaust apparatus. 2. The method of claim 1, further comprising:disposing of the metal fluorite-based inorganic material having the radioactive species adsorbed thereon. 3. The method of claim 1, further comprising:releasing the radioactive species from the metal fluorite-based inorganic material into a medium selected from the group consisting of a second gas stream, a liquid extraction medium, and a solid extraction medium for chemical separation or concentration. 4. The method of claim 1, wherein flowing the gas stream through the exhaust apparatus comprises flowing through a nanoporous metal fluorite-based inorganic material. 5. The method of claim 1, wherein flowing the gas stream through the exhaust apparatus comprises flowing through a natural or a synthetic aluminum (Al)-rich fluorite. 6. The method of claim 5, wherein the flowing is performed through a synthetic aluminum (Al)-rich fluorite with a surface area greater than approximately 1 square meter per gram (m2/g). 7. The method of claim 1, wherein removing the radioactive species from the gas stream comprises removing 129I nuclei.