Non-destructive control of the plutonium content of spent fuel under uncertainties on irradiation history

It is apparent that serious attention must be given to the use of weapons-grade plutonium in fuel cycles in nuclear power plants. It is becoming increasingly necessary to organize a mixed fuel cycle which would be presumed to have ordinary, low-enriched uranium fuel and weapons-grade plutonium fuel in a one-time reactor core loading. This research examined the problem of how to detect the possible substitution of a low-enriched uranium bundle for a bundle containing weapons-grade plutonium. Final determination of fuel assembly substitution was made using a non-destructive control methodology, which was based on gamma-spectra analysis of spent fuel for initial fuel composition identification