Year
1986
Abstract
A method has been developped for the french reprocessing plants in order to Identify PWR and BWP fuel assemblies before dissolution. The method is based on the conroarison of announced values (reactor operator value] and measured values in the reprocessing plant for burn-up and cooling time of the fuel assembly. The method uses high resolution gamma spectrometry and passive neutron counting technique. The ratios Cs134/Cs137 and Ce144/Cs137 are respectively used to obtain bumup value and cooling time. The total neutron emission is also used to obtain the burn-up value. The results of measurement campaigns on PWR and BWR show that a precision of + 5 ! is reached for burn-up values >, the coolinp time is determined with an uncertainty of + SO day's7 for cooling time of 2500 days.. Using the'values of burn-up and total neutron emission it is possible to determine the Plutonium amount a lot of \"fuel assemblies drs-rcharged from the same irradiation cycle of a given reactor. This amount is determined with an uncertainty less than +1%.