| 摘要 |
PURPOSE:To analyze immediately the cause of generation of abnormality of a nuclear power plant by detecting and recording a drop state of a control rod. CONSTITUTION:When a control rod driving shaft 2 drops in order of windings 1b, 1a, an output of a differential amplifier 7 is stored in a storage device 8 through an AC/DC converter 10 and an A/D converter 9-1. Also, the storage device 8 always receives in the same state a signal from A/D converters 9-2-9-n corresponding to other control rods of (n) pieces, and these signals are stored for a constant interval of time, and also the storage is updated at every constant interval of time. On the other hand, a controlling circuit 13 decides that the control rod has dropped when a signal generated in a drop detecting resistance 14 becomes larger than a set signal of a setting device 11, stops updating the storgae of the storage device 8, and also records the stored contents in a recorder 15. In this way, a drop state of the control rod is recorded, therefore, the cause of abnormality of a nuclear power plant can be analyzed immediately. |
