Patent Number: 
Section: claims

1. A method for manufacturing 99Mo radioisotope, the method comprising:providing a source containing a first mass of uranium particles, the uranium particles having an average particle size of from 10% to 200% of a recoil distance of 99Mo in the uranium particles;enclosing the source in a neutronically-translucent container;exposing the source to neutrons, thereby reducing the first mass of uranium particles in the source to a second mass of uranium particles less than the first mass and creating at least some atoms of the 99Mo radioisotope;removing, after exposing the source to neutrons, at least some of the atoms of the 99Mo radioisotope from the source without removing uranium particles from the source;wherein the removing operation further comprises:passing an extraction material selected to dissolve the 99Mo radioisotope through the container, thereby contacting the uranium particles with the extraction material; andwherein the extraction material is supercritical carbon dioxide containing a ligand that dissolves the 99Mo radioisotope and does not dissolve the uranium. 2. The method of claim 1 wherein the removing operation removes less than 0.01% of the uranium from the second mass of uranium particles in the source. 3. The method of claim 1 wherein the removing operation removes less than 0.1% of the uranium from the second mass of uranium particles in the source. 4. The method of claim 1 wherein the providing operation further comprises:providing a source made at least partially from particles containing uranium oxide or uranium metal. 5. The method of claim 1, wherein exposing the source further comprises exposing the container enclosing the source to neutrons. 6. The method of claim 1 further comprising:selecting an extraction material that dissolves atoms of the 99Mo radioisotope without changing the phase of the uranium in the source. 7. The method of claim 1 further comprising:selecting an extraction material in which atoms of the 99Mo radioisotope are more soluble than atoms of uranium. 8. The method of claim 6 further comprising:determining the form of the source based on the selected extraction material. 9. The method of claim 1 further comprising:selecting a combination of a source and an extraction material, wherein the combination allows 99Mo radioisotope to be removed from the source after exposure to neutrons without dissolving uranium in the source. 10. The method of claim 1 wherein the ligand is selected from 8-hydroxyquinoline, a-benzoinoxime, disodium 4,5-dihydroxy-1,3-benzenedisulfonate, phosphate compounds, and diketone compounds. 11. The method of claim 1 wherein the ligand has one or more functional groups selected from hydroxyl, carbonyl, diketones, aldehyde, haloformyl, carbonate ester, carboxylate, ester, ether, peroxy, amine, carboxamide, imide, imine, nitrate, cyanate, thiol, sulfide, sulfinyl, sulfonyl, thiocyanate, isothiocyanate, phosphate, and phosphono groups. 12. The method of claim 5 further comprising:repeatedly performing the exposing operation and the removing operations on the container without removing the uranium from the container. 13. The method of claim 11 further comprising:removing the 99Mo radioisotope from the extraction material. 14. The method of claim 1 further comprising:after the removing operation, repeating the exposing operation on the same source. 15. The method of claim 1 further comprising:removing, in addition to the 99Mo radioisotope, an amount of one or more other fission products created during the exposing operation. 16. The method of claim 1 wherein the uranium particles are loose grains of material containing uranium.