SUPPORT STRUCTURE DETECTION

• US 20150106055A1
• Filed: 11/25/2014
• Published: 04/16/2015
• Est. Priority Date: 03/30/2012
• Status: Active Grant

• Current Assignee: Atomic Energy of Canada Limited (Government of Canada)
• Original Assignee: Atomic Energy of Canada Limited (Government of Canada)
• Inventors: Craig, Stuart Thomas, Chaplin, Kenneth Robert
• Granted Patent: US 10,444,012 B2
• Time in Patent Office: Days
• US Class Current: 702/157
• CPC Class Codes: G01B 21/14 internal diameters of boreholes or wells E21B47/08
• CPC Class Codes: G21C 1/20 moderator being liquid, e.g. pressure-tube reactor
• CPC Class Codes: G21C 17/00 Monitoring; Testing measuring in general G01; Maintaining
• CPC Class Codes: G21C 17/06 Devices or arrangements for monitoring or testing fuel or fuel elements outside the reactor core, e.g. for burn-up, for contamination G21C17/08, G21C17/10 take precedence; detecting leaking fuel elements during reactor operation G21C17/04
• CPC Class Codes: G21D 3/001 Computer implemented control
• CPC Class Codes: Y02E 30/00 Energy generation of nuclear origin
• CPC Class Codes: Y02E 30/30 Nuclear fission reactors

Abstract

While the typically-collected diameter data contains information for detecting some garter springs, many garter springs may not be detected without processing the diameter data. Responsively, a method for processing the diameter data to detect the garter springs has been developed. In particular, the processing involves fitting of the diameter data to a shape, determining residual errors and using the residual errors to locate garter springs.

Claims

1. A method of locating a support structure external to a tube, said method comprising:

receiving a plurality of data points, where said receiving includes receiving a data point representative of a diameter of said tube at each of a plurality of angular offsets for a first range of axial positions in said tube;

fitting a shape to said plurality of data points;

determining an integrated residual error between said data points and said set of circles;

associating said integrated residual error with said first range of axial positions;

repeating said receiving, fitting, determining and associating for a further plurality of axial positions, thereby producing a plurality of integrated residual errors; and

indicating, as a location of said support structure, an axial position associated with a local maximum integrated residual error among said plurality of integrated residual errors.

2. The method of claim 1 further comprising filtering said plurality of integrated residual errors.

3. The method of claim 2 wherein said filtering comprises applying a digital filter to said plurality of integrated residual errors.

4. The method of claim 3 wherein said digital filter comprises a three-stage digital filter.

5. The method of claim 4 wherein a first stage of said three-stage digital filter comprises a 6th order infinite impulse response Butterworth low pass filter, with a 3 dB cut off at 18 mm.

6. The method of claim 4 wherein a second stage of said three-stage digital filter comprises a 4th order finite impulse response derivative filter.

7. The method of claim 4 wherein a third stage of said three-stage digital filter comprises an order 40 finite impulse response step change cross correlation filter.

8. The method of claim 1 wherein said shape is a circle.

9. The method of claim 1 wherein said shape is an ellipse.

10. The method of claim 1 wherein support structure comprises a garter spring.

11. A device comprising:

a processor adapted to;

receive a plurality of data points, where said processor is adapted to receive a data point representative of a diameter of a tube at each of a plurality of angular offsets for a first range of axial positions in said tube;

fit a shape to said plurality of data points;

determine an integrated residual error between said data points and said set of circles;

associate said integrated residual error with said first range of axial positions;

repeat said receiving, fitting, determining and associating for a further plurality of axial positions, thereby producing a plurality of integrated residual errors; and

indicate, as a location of said support structure, an axial position associated with a local maximum integrated residual error among said plurality of integrated residual errors.

12. A computer readable medium containing computer-executable instructions that, when performed by a processor, cause said processor to:

receive a plurality of data points, where said instructions cause said processor to receive a data point representative of a diameter of said tube at each of a plurality of angular offsets for a first range of axial positions in said tube;

fit a shape to said plurality of data points;

determine an integrated residual error between said data points and said set of circles;

associate said integrated residual error with said first range of axial positions;

repeat said receiving, fitting, determining and associating for a further plurality of axial positions, thereby producing a plurality of integrated residual errors; and

indicate, as a location of said support structure, an axial position associated with a local maximum integrated residual error among said plurality of integrated residual errors.