NUCLEAR POWER STATION ROD POSITION DETECTION SYSTEM AND FREE ROD DROPPING TIME TESTING METHOD THEREOF

摘要

A nuclear power station rod position detection system and a free rod dropping time testing method thereof. The detection system includes a position probing device (1) and a control rod set (3) provided inside a pressure container (4), wherein the position probing device (1) is installed outside a journey casing (7) and connected to the control rod set (3) via a control rod drive mechanism (2), the position probing device (1) includes a plurality of consecutive control units, each control unit containing two kinds of coils, namely a sensor coil (8) and a rod dropping testing coil (9). A plurality of sensor coils are powered by a transformer T1 and the rod dropping testing coil (9) of each control unit forms the leading end of two testing sensor voltages by being connected to each other from top to tail. The nuclear power station rod position detection system and a free rod dropping time testing method thereof provided in the present invention obtain a rod dropping time curve by setting a rod dropping testing coil and using the voltage sensed in the rod dropping testing coil during the rapid dropping of the control rod, which is convenient to test the feed rod dropping time and further improves testing reliability.