In
nuclear power technology,
burnup (also known as
fuel utilization) is a measure of how much energy is extracted from a primary
nuclear fuel source. It is measured both as the fraction of fuel atoms that underwent fission in %FIMA (fissions per initial metal atom) and as the actual energy released per mass of initial fuel in
gigawatt-days/
metric ton of
heavy metal (GWd/tHM), or similar units.