Production Experience During Sneak Platelet Fabrication

As a first production job ALKEM (Leopoldshafen) had to produce about 6000 platelets for the SNEAK fast critical assembly. Maintaining outer geometry as used for metals, and providing oxide mixture as a stable fuel matrix instead of a metal plate, gives unusually severe tolerance problems. More than 45 000 precise sintered bodies with narrow specifications had to be produced. Safety requirements for SNEAK demand an intimate mixture of UO2 with PuO2, whereas physics considerations lead to a high degree of uniformity in the Pu/U-ratio between different platelets. Details are given on the production process starting with powder characterization, mixing, pressing, de-waxing and sintering of rectangular pellets. Further information is provided about product control, filling and closure technique for the platelet cans. Experience with the training of the working crew, and with alarm- and accounting systems and chemical scrap recovery is reported. (author)