Verfahren zum Gewinnen von in einem Graphitkoerper eingebetteten Materialien

摘要

Uranium and/or thorium carbide and/or oxide and fission products embedded in a graphite body are extracted by heating the body and subjecting it to the action of the vapour of an elementary halogen or a halogen compound whereby the graphite disintegrates and said substances may be removed. Elementary bromine, fluorine, or iodine may be used, or the compounds bromine chloride or iodine chloride; reference is also made to compounds of bromine and carbon. The destruction of the graphite structure may be completed by the application of pressure and the embedded material removed by leaching with acid or by treatment with a reagent which forms volatile compounds. Heating of spent coated nuclear fuel particles to 2500 DEG -3000 DEG C. serves to break down the coating on the fuel particles. In the illustrated embodiment said particles embedded in graphite body 3 contained in quartz tube 1, before or after such heat treatment are heated with elementary bromine at 200 DEG -300 DEG C. by means of removable oven 4. Thereafter the fuel is heated at 600 DEG -1100 DEG C. in chlorine gas admitted at 11, or in nitrogen or an inert gas saturated with CCl4; S2Cl2 may be added to aid the formation of volatile chlorides. Uranium and thorium chlorides sublime together with some of the fission products and condense in bulb 8. Reference is also made to embedded particles consisting of molybdenum coated with Al2O3.