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Control Rod Guide Tube PWR Internals Replacement

The leader in upper internals work

The Challenge

The control rod guide tube is a safety component which ensures timely control rod drop. Its role is also to guide the rod during step-by-step movements. Wear may occur on the guide plates, in which case guide tube replacement is required.

The Solution

Framatome offers solutions for guide tube removal and replacement. Our customers can choose to replace a guide tube either with a new tube or with a refurbished tube. Two guide tubes can also be switched.

Technical Features

The work is performed underwater during a normal outage while the upper internals are on their stand. The operators work from the refuel bridge or an auxiliary platform.

  • The guide tube is removed and installed using specific tools such as:
    — An umbrella gripper to maintain the upper and lower parts of the guide tubes together
    — A tool for screwing/unscrewing, torqueing / detorquing, locking cup reshaping, etc.
  • Cover plates placed on the guide tube support to prevent the ingress of loose parts
  • Electrical discharge machining to repair any screws found to be jammed
  • In case of replacement with a new guide tube, the old tube is placed in a specific storage container

Features & Benefits

  • Uninterrupted experience with more than 40 guide tubes replaced over the past 20 years
  • The continuous experience of our experts, engineers, and operators means they are operational immediately
  • Intensive R&D program over the past few years to develop updated tools with new technologies (patented)

Highlights of the AREVA Repair Process

• Thermal Sleeve Removal (If Applicable)

• Roll Nozzle in Repair Region

• Machine Weld Prep & PT Weld Area

• Perform Ambient Temperature Temper Bead Structural Weld

• Prepare Welded Surface For NDE

• Perform Post-Repair UT & PT

• Remediate Rolled and Repaired Areas

• Install Replacement Thermal Sleeve (If Required)

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Contact Us

Lisa Hawkins
Business Development Manager, CR&R
Tel: 434.832.2858