The development of computer-aided extraction-status diagnostic technique at the Tokai Reprocessing Plant

The computer aided system that automatically diagnoses the status of the extraction process is under development at the Tokai Reprocessing Plant (TRP), Power Reactor and Nuclear Fuel Development Corporation (PNC). The second extraction cycle of TRP was chosen as the base model of this system. It was shown in ISEC'90 that the combination of the CCT (Cause Consequence Tree) and the determination of the extraction profile-change by the indication pattern of in-line monitors (Table-Treatment) is the best way for the automatic diagnosis and the cause identification of the anomaly. The cause of the anomaly that changes Pu profile will be identified by the change of the indication pattern of neutron monitors by the Table-treatment. However this method greatly depends on how accurately the indication pattern of neutron monitors can be identified. In this study the fluctuation of the indication of neutron monitors was examined by investigating the actual record of the neutron monitors obtained in the TRP's operation, and the method of signal treatment was proposed. As a result, it was confirmed that the cause of the anomaly can be identified by the indication pattern of neutron monitors, with an appropriate signal treatment. (author)