Apparatus and method for inspecting a control rod drive mechanism penetration tube for degradation

An apparatus for inspecting a tube for degradation, the tube having an inner surface surrounding a sleeve rotatably and translatably disposed in the tube, the sleeve having an inside surface and nonuniform material properties, comprising:

• (a) a support body sized to be disposed within the sleeve;
• (b) an expandable bladder surrounding said support body and connected thereto to intimately engage the inside surface of the sleeve for securing said support body to the inside surface of the sleeve;
• (c) a sensor connected to said support body for sensing the degradation in the tube, said sensor adapted to transmit energy through the sleeve and into the tube and adapted to sense energy perturbations in the sleeve and the tube;
• and
• (d) a rotator connected to said support body for rotating said support body, whereby said support body, said bladder, said sensor and the sleeve simultaneously rotate within the tube as said rotator rotates said support body so that said sensor radially senses the tube for degradation and whereby the sleeve is stationary relative to said sensor as said rotator rotates said support body so that the material properties of the sleeve are radially invariant relative to said sensor.

In a reactor pressure vessel closure head, an apparatus for nondestructively inspecting a reactor pressure vessel penetration tube for degradation, the tube having an inner surface surrounding a freely rotatable and translatable sleeve concentrically mounted in the tube, the sleeve having an inside surface and nonuniform material properties, the apparatus comprising:

• (a) an elongate support body having a longitudinal axis and sized to be disposed within the sleeve, said support body having an exterior surface thereon and a channel inside said support body which terminates in an opening on the exterior surface of said support body;
• (b) a radially expandable bladder surrounding a portion of said support body and connected thereto to intimately engage the inside surface of the sleeve for securing said support body to the inside surface, said bladder covering the opening;
• (c) a sensor connected to said support body for sensing the degradation in the tube, said sensor adapted to transmit energy through the sleeve and into the tube and adapted to sense energy perturbations in the sleeve and the tube, said sensor adapted to generate an electrical signal in response to the energy perturbations sensed thereby;
• (d) a rotator connected to said support body for rotating said support body about the longitudinal axis of the support body, whereby said support body, said bladder, said sensor and the sleeve simultaneously rotate in the tube as said rotator rotates said support body, so that said sensor radially senses the tube for degradation and whereby the sleeve is stationary relative to said sensor as said rotator rotates said support body so that the material properties of the sleeve through which the energy is transmitted are radially invariant relative to said sensor;
• and
• (e) a pusher/puller mechanism connected to said support body for translating said support body in the tube, whereby said support body, said sensor, said bladder and the sleeve simultaneously translate in the tube as said pusher/puller mechanism translates said support body so that said sensor axially scans the tube for degradation and whereby the sleeve is stationary relative to said sensor as said pusher/puller mechanism translates said support body so that the material properties of the sleeve through which the energy is transmitted are axially invariant relative to said sensor.

In a nuclear system, an apparatus for inspecting a tubular member of the nuclear system for degradation, the tubular member surrounding a movable sleeve, comprising:

• (a) a sensor for sensing the degradation of the tubular member over an incremental portion of the tubular member at a given point in time, the sensor being sized to be inserted within the sleeve;
• (b) means for maintaining the sensor in fixed relation to the sleeve, so that the sensor always focuses on the same portion of the sleeve when in a sensing mode as the sleeve is moved;
• and
• (c) means for moving the sensor and the sleeve within the tubular member over the incremental portion of the tubular member to be inspected.

A method of inspecting a tubular member for degradation, the tubular member surrounding a rotatable sleeve, comprising the steps of:

• (a) disposing a support body in the sleeve, the support body having a bladder and a sensor connected thereto;
• (b) securing the support body to the sleeve by engaging the bladder with the sleeve;
• (c) operating the sensor for sensing the degradation in the tubular member;
• (d) rotating the support body by operating a rotator connected thereto, whereby the support body, the bladder, the sensor and the sleeve simultaneously rotate in the tubular member as the rotator rotates the support body.

A method of inspecting a tube for degradation, the tube having an inner surface surrounding a rotatable and translatable sleeve, the sleeve having an inside surface and nonuniform material properties, comprising the steps of:

• (a) disposing a support body within the sleeve, the support body having an expandable bladder surrounding the support body and connected thereto, the support body having a sensor connected thereto;
• (b) securing the support body to the inside surface of the sleeve by expanding the bladder into intimate engagement with the inside surface of the sleeve;
• (c) operating the sensor to transmit energy through the sleeve and into the tube and to sense energy perturbations in the sleeve and the tube for sensing degradation in the tube;
• and
• (d) rotating the support body by operating a rotator connected to the support body, whereby the support body, the bladder, the sensor and the sleeve simultaneously rotate within the tube as the rotator rotates the support body, so that the sensor radially scans the tube for degradation and whereby the sleeve is stationary relative to the sensor as the rotator rotates the support body so that the material properties of the sleeve are radially invariant relative to the sensor.

In a reactor pressure vessel closure head, a method of nondestructively inspecting a reactor pressure vessel penetration tube for degradation, the tube having an inner surface surrounding a rotatable and translatable sleeve concentrically mounted in the tube, the sleeve having an inside surface and nonuniform material properties, the method comprising the steps of:

• (a) disposing an elongate support body within the inner surface of the tube, the support body having a longitudinal axis, the support body having an exterior surface thereon and a channel inside the support body which terminates in an opening on the exterior surface of the support body, the support body having a radially expandable bladder surrounding a portion of the support body and connected thereto, the support body having a sensor connected thereto to sense the tube for degradation, the sensor adapted to transmit energy through the sleeve and into the tube and adapted to sense energy perturbations in the sleeve and the tube, the sensor adapted to generate an electrical signal in response to the energy perturbations sensed thereby;
• (b) securing the support body within the sleeve by radially expanding the bladder into intimate engagement with the inside surface of the sleeve, said step of securing the support body to the inside surface of the sleeve including the step of supplying a fluid to the bladder for expanding the bladder by releasing the fluid from a fluid reservoir connected to the bladder;
• (c) operating the sensor to transmit energy through the sleeve and into the tube and to sense energy perturbations in the sleeve and the tube for sensing the degradation in the tube, the sensor capable of generating an electrical signal in response to the energy perturbations sensed thereby;
• (d) rotating the support body about the longitudinal axis of the support body by operating a rotator connected to the support body, whereby the support body, the bladder, the sensor and the sleeve simultaneously rotate within the tube as the rotator rotates the support body, so that the sensor radially senses the tube for degradation and whereby the sleeve is stationary relative to the sensor as the rotator rotates the support body so that the material properties of the sleeve through which the energy is transmitted are radially invariant relative to the sensor;
• and
• (e) translating the support body in the tube by operating a pusher/puller mechanism connected to the support body, whereby the support body, the bladder, the sensor and the sleeve simultaneously translate within the tube as the pusher/puller mechanism translates the support body, so that the sensor axially senses the tube for degradation and whereby the sleeve is stationary relative to the sensor as the pusher/puller mechanism translates the support body so that the material properties of the sleeve through which the energy is transmitted are axially invariant relative to the sensor.