Dry recovering method for nuclear fuel oxide pellets

Purpose: To satisfactorily oxidize and pulverize scrap pellets and enable the reuse of them as powderous starting material. Constitution: Scrap pellets as rejected products of nuclear fuel oxide pellets are subjected to differential thermal analysis to draw a differential thermal curve. Then, a temperature at which the subsequent one of two peaks on the differential thermal curve appears is determined, and the pellets are heated at the same temperature and in the same atmosphere to powderize them through oxidizing pulverization. Oxygen atmosphere is superior to dry air atmosphere since finer powder can be recovered in the former. Since no mechanical pulverizing means is used, recovered powder can be obtained efficiently with no risk of impurity incorporation or radiation exposure. (Sekiya, K.)