Operational experience with the automatic lead-spectrometer facility for nuclear safeguards

In 1969 INTERATOM received a contract from the Karlsruhe Nuclear Research Centre for the development, design and construction and start-up of an automatic lead-spectrometer facility for controlling the flow of fissile material at the product end of a LWR fuel-pin fabrication plant. The main features of the plant design are the application of pulsed-neutron active-interrogation technique with multi-isotope fissile-material assay capability, the adaptability to customers requirements, the design for heavy-duty operation and its simplicity and ease of operability. An on-line process-computer system coordinates and controls the sequence of the measurements, surveys the plant operation and is responsible for data acquisition and evaluation. The evaluation program, as organized, includes self-checking possibilities to detect malfunctioning of component parts. To minimize evaluation errors, this program is capable of differentiating between fuel pins with varying pellet column lengths and/or pins with varying enrichment as compared to a reference pin. Subsequent to the testing of the plant components, a continuous operation under field conditions was carried out. During this test, fulfilment of the specification, performance of the components, reproducibility, availability, safety and assay accuracy could be demonstrated. After a training period of four weeks, the operation of the plant was taken over by a technician.