On-line spent fuels plutonium evaluation for safeguards at the head ends of a large scale preprocessing plant using non destructive assay

A modern large scale reprocessing plan can today reprocess 800 tons of spent fuel per year. Since 7 to 8 tons of plutonium result from the chemical reperations, safeguarding such plants is a challenge. Safeguards concerns for future plants lead the French Support Program to the IAEA to ask the Prench Atomic Energy Commision (CEA) to study the amounts and total neutronic emission rates have been carried out using a theoretical approach cominded with experimental data provided by the UP3 COGEMA plant at LA HAGUE. The total neutronic emmission rate is measured in necessary and if initial enrichments are known, correlation accuracy in terms of totaly plutonium amounts, is within 1% of PWR and 5% BWR assemblies.