Nuclear reactor remote disconnect control rod coupling indicator
AssigneeThe United States of America as represented by the United States Energy Research and Development Administration
InventorMichael Vuckovich
Life of this patent
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Abstract
A coupling indicator for use with nuclear reactor control rod assemblies which have remotely disengageable couplings between the control rod and the control rod drive shaft. The coupling indicator indicates whether the control rod and the control rod drive shaft are engaged or disengaged. A resistive network, utilizing magnetic reed switches, senses the position of the control rod drive mechanism lead screw and the control rod position indicating tube, and the relative position of these two elements with respect to each other is compared to determine whether the coupling is engaged or disengaged.
Claims10
A coupling indicator system for use with remotely disengageable control rod assemblies wherein the connection of an elongated control rod to an elongated control rod drive shaft is dependent upon the longitudinal axial position of a plunger, one position of said plunger creating coupling between said control rod and said drive shaft, and a second position of said plunger creating uncoupling between said control rod and said drive shaft, said control rod assembly including a control rod drive means, movable along the drive shaft longitudinal axis, for axially moving said drive shaft along the drive shaft longitudinal axis, said coupling indicator system comprising:
- means for determining the axial position of said plunger;
- means for determining the axial position of said drive means;
- and
- means for comparing the axial position of said plunger with respect to the axial position of said drive means,
- said means for determining the axial position of said plunger comprising:
- an elongated position indicator tube fixedly secured to and axially movable with, said plunger;
- a position indicator magnet secured to said position indicator tube;
- a plurality of equal resistances serially connected and having a first end point and a second end point;
- a common node;
- a plurality of normally non-conducting magnetically actuated switches parallelly connected between said resistances and said common node, one of said magnetically actuated switches being connected between each pair of adjacent resistances, said magnetically actuated switches being located such that at least one magnetically actuated switch is in magnetic communication with said position indicator magnet to cause such switch to conduct electric current;
- a first current source having a first electrical polarity serially connected to said plurality of resistances at said first end point;
- and
- means for measuring the voltage generated between said first current source and said common node to obtain a first voltage.
Dependencies are inferred from the claim text.