Details of the analysis algorithms provided for the implementation of the packaging program at the BN-350 reactor, MAEC, AKTAU, Kasakhstan

Abstract

At the request of the KAEA, MAEC and DOE-NN42 analysis algorithms and diagrams to help implement the safe packaging of spent fuel assemblies were developed. These analysis algorithms are based on observable radiation signatures measured with the IAEA`s UnderWater Neutron Coincidence Counter (UWNCC), which was designed at Los Alamos, and shared with the BN-350 facility. The parameters to be determined from the UWNCC measurement station are the assembly mass, the assembly type (Blanket, Driver or Other) and total heat output. The total assembly mass is provided from a load cell located on a crane installed at the facility that is used to position the assembly during measurements in the UWNCC. The load cell readout can be observed on the crane control panel or via the IAEA`s UWNCC control software. The assembly type identification uses a relationship between the measured total gamma-ray output and the measured neutron doubles rate from the assembly at the axial mid-plane position. The neutron doubles rate is proportional to the quantity of fissile mass contained within the assembly and the total gamma-ray output is proportional to the burn-up of the assembly. The heat output is determined from the measured total gamma-ray output of the assemblies. Thismore » measured value is converted to heat output based on a correlation to heat calculations performed by ANL for the set of assemblies measured during the calibration and UWNCC verification phase of the project. The figures attached in the appendix are the figures transmitted to the facility for use during packaging.« less