FAST REACTOR USING HEAVY LIQUID-METAL COOLANT Russian patent published in 2001 - IPC

FIELD: nuclear power engineering. SUBSTANCE: reactor has core holding uranium- plutonium nitride fuel and divided into sub-cores. Nuclear fuel is accommodated in cans of fuel elements where it is placed in a spaced relation to can walls this space being filled with material of high heat conductivity. Fuel elements are grouped in can-free fuel assemblies. The latter are cooled down by means of coolant prepared from lead or lead-bismuth alloy. Mass proportion of uranium and plutonium in fuel is chosen between 5.7 and 7.3 and is similar throughout entire core. Each next sub-core starting from core center to its periphery has more fuel and less amount of coolant either due to variation in element-to-element space in different sub-cores or due to different diameters of fuel elements in different sub-cores, or else, due to different element-to-element spaces and fuel-element diameters in different subcores. EFFECT: improved fuel burn-up uniformity and rate of plutonium breeding; eliminated runaway of reactor. 9 cl