Eddy current position indicating apparatus for measuring displacements of core components of a liquid metal nuclear reactor
AssigneeWestinghouse Electric Corp.
InventorsClifford K. Day, James L. Stringer
Life of this patent
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Abstract
Apparatus for measuring displacements of core components of a liquid metal fast breeder reactor by means of an eddy current probe. The active portion of the probe is located within a dry thimble which is supported on a stationary portion of the reactor core support structure. Split rings of metal, having a resistivity significantly different than sodium, are fixedly mounted on the core component to be monitored. The split rings are slidably positioned around, concentric with the probe and symmetrically situated along the axis of the probe so that motion of the ring along the axis of the probe produces a proportional change in the probes electrical output.
Claims11
Apparatus for measuring displacements of a component of a liquid metal nuclear reactor immersed within the liquid metal coolant comprising:
- an eddy current probe having a primary and secondary winding,
- a dry thimble, adapted to be supported by a stationary portion of the reactor within the liquid metal coolant, housing the eddy current probe, which is stationarily supported therein during operation of the probe, and isolating the probe from the coolant, and
- an electrically conductive annular ring with resistivity significantly different than the liquid metal coolant rigidly affixed to the component being monitored and slidably positioned around the periphery of the thimble concentric with the probe and symmetrically situated along the primary and secondary windings of the probe so that motion of the ring along the probe produces a proportional change in current in the secondary winding electrical output and wherein the annular ring includes a resistivity discontinuity formed from a cavity within the ring filled with a substance having a resistivity significantly different from the annular ring and the liquid metal coolant.
A liquid metal reactor core component displacement monitor comprising:
- an eddy current probe having a primary winding and first and second secondary coils symmetrically positioned on either side of the primary winding along a common axis, the probe being stationarily supported within the liquid metal reactor coolant proximate the core;
- and
- an electrically conductive annular ring having a resistivity significantly different than the liquid metal coolant of the reactor rigidly coupled to the core and slidably mounted around the periphery of the probe in a manner to effect electromagnetic coupling between the primary and the first and second secondary coils with the efficiency of the coupling dependent upon the axial location of the ring between the first and second secondary coils and wherein the annular ring includes a resistivity discontinuity formed from a cavity within the ring filled with a substance having a resistivity significantly different from the annular ring and the liquid metal coolant.
Dependencies are inferred from the claim text.