PELLETIZED NUCLEAR FUEL Russian patent published in 2002 - IPC

FIELD: nuclear power engineering; uranium dioxide base fuel pellets. SUBSTANCE: according to first alternative uranium dioxide pellet has in its composition 0.03 to 0.10 mass percent of aluminum and 0.01 to 0.05 mass percent of silicon both distributed in the form of oxides over boundaries of uranium dioxide grains in the form of easy-melting eutectic; according to second alternative uranium dioxide pellet has in its composition, mas.%: aluminum, 0.03-0.10; silicon, 0.01-0.05; and niobium, 0.05-0.15; aluminum and silicon being distributed in the form of oxides over boundaries of uranium dioxide grains in the form of easy-melting eutectic and niobium, in the form oxides produces solid solution together with uranium dioxide; according to third alternative uranium dioxide pellet has in its composition 0.04-0.15 mas.% of iron, and 0.01-0.04 mas.% of silicon, both being distributed in the form of oxides mainly over boundaries of uranium dioxide grains in the form of easy-melting eutectic also incorporating in its composition iron in the form of oxides; remaining part of iron in the form of oxides produces solid solution together with uranium dioxide grains; according to fourth alternative uranium dioxide pellet has in its composition 0.04-0.15 mas.% of iron, 0.02-0.05 mas.% of aluminum, 0.01-0.04 mas.% of silicon, and 0.05-0.15 mas.% of niobium, aluminum and silicon being distributed in the form of oxides mainly over boundaries of uranium dioxide grains in the form of easy-melting eutectic incorporating in its composition part of iron in the form of oxide; remaining part of iron and niobium in the form of oxide produce solid solution together with grain material of uranium dioxide. Invention also discloses five methods for manufacturing palletized nuclear fuel. EFFECT: enhanced plasticity of fuel material at operating temperatures which reduces mechanical interaction between fuel pile and fuel element cladding. 31 cl, 3 dwg, 1 tbl