NUCLEAR FUEL BURNUP ESTIMATION DEVICE, METHOD, AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a nuclear fuel burnup estimation technology in which the accurate grasping of the amount of cesium indefinite in shape becomes much more difficult.SOLUTION: An estimation device 20 includes: a counting unit 21 for counting a counting rate of two or more of energy characteristic values 2186 keV or 1489 keV and Eu 154 of Pr 144 output from a detector 12 having detected gamma rays emitted from the nuclear fuel; a correction unit 22 for acquiring a correction counting rate which corrects the counting rate of Pr 144 and Eu 154 on the basis of a radiation branch ratio regulated by each nuclide; a dividing unit 25 dividing the correction counting rate of Pr 144 by the correction counting rate of Eu 154 to be defined as a radioactivity ratio; an adjusting unit 26 adjusting the radioactivity ratio with a radioactivity attenuation rate and a relative measuring efficiency during a cooling period for a reactor to be defined as an adjusting radioactivity ratio M; and a comparison unit 27 for comparing the adjusting radioactivity ratio M with previously held correlative data, thereby estimating the burnup of the radioactive fuel.