Internal accounting system for feed materials in the plutonium fuel fabrication complex at Cadarache

The internal accounting system of the Fabrication and Radiometallurgical Inspection Service (SFER) is basically designed to meet national and international requirements for nuclear materials accountancy as applied to feed materials. The authors discuss the principles underlying this accounting system for the case of the Plutonium Fuel Assembly Fabrication Complex at Cadarache. The sphere of application of the system covers more than 200 work stations and approximately 100 different materials. Some 20000 movements of feed materials per year represent transfers of a cumulative mass much greater than one ton of fissile material. A data processing system has therefore become essential in order to ensure the rapid and reliable acquisition of accounting data relating to these movements. The authors describe the system (definition of stations and material codes, description of supporting facilities used) and discuss the mode of acquisition with particular reference to relative speed of action. In conclusion, the authors indicate that the system offers interesting possibilities, in addition to its original purpose, in the following areas: Preparation of material balances; compliance with safety regulations to avert the risk of criticality; discouragement of possible diversion. (author)