FEASIBILITY STUDY OF U-235, PU-239 AND PU-240 CONTENT DETERMINANT IN AN IRRADIATED FUEL BY NEUTRON TRANSMISSION ANALYSIS

A proposed nondestructive method and its feasibility for the determina tion of U-235, Pu-239 and Pu-240 contents in an irradiated fuel is des cribed. The method is based on the use of shape fit analysis of the Ti me-Of-Flight (TOF) neutron transmission data of the irradiated fuel fo r neutron energies below 3 eV. The neutron transmission experiment of the irradiated fuel is planned to carry out using one of the TOF spect rometers installed at ET-RR-1 reactor. The computer code SHAPE is adap ted taking into account the known parameters of resonances of certain fissile and fission product nuclei to provide the fit analysis. The co ntent of the gross-fissile and fission product isotopes are determined from the burn-up calculations of the fuel assembly of the ET-RR-1 rea ctor with defined history. The effect of both uncertainties in resonan ce parameters on the deduced contents of fissile nuclei and statistica l accuracy of the TOF measurements are estimated. (C) 1998 Elsevier Sc ience Ltd. All rights reserved.