High resolution digital rod position indication system for nuclear power plants

摘要

A high resolution digital rod position indication (high resolution DRPI) system having improved resolution. The high resolution DRPI system monitors the rod control cluster and provides an indication of the rod position with precision to a single step. In addition, the high resolution DRPI system is capable of producing a rod position output compatible with existing rod control systems. The improved resolution of the high resolution DRPI system allows the actual position of the control rods to be continuously monitored and eliminates the need for or reduces the frequency of offline re-initialization of the step counters.

主权项

1. A high resolution digital rod position indication system for determining an axial position of a control rod within a reactor, the control rod being coupled to a drive rod that is moved by predetermined increments spaced apart along a range of motion, said high resolution digital rod position indication system comprising:
a plurality of detection coils spaced apart at predetermined intervals, the spacing of the predetermined intervals being greater than the spacing of the predetermined increments, adapted to be excited by a low voltage ac source, each of said plurality of detection coils adapted to sense the presence of the drive rod, each of said plurality of detection coils adapted to produce an output signal, said output signals having fluctuations corresponding to each incremental movement of the drive rod; a data acquisition unit adapted to be placed in electrical communication with each detection coil of the plurality of the detection coils, said data acquisition unit sampling said output signals from the plurality of the detection coils; a processing unit in communication with said data acquisition unit, said processing unit deriving the axial position of the control rod, relative to each predetermined increment, based on said fluctuations corresponding to the incremental movements.