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PWR Internals Repair & Replacement

Solutions for All of Your Internals Needs

Clevis Bolt Replacement

CRGT Replacement & Shuffles

If inspections indicate unacceptable wear on the Control Rod Guide Tubes (CRGT), AREVA has the ability to perform removal operations and install new CRGTs in the upper internals. CRGTs may also be swapped with spare locations.

Internals Bolting Replacement – Baffle Bolts

AREVA performed the first U.S. nuclear plant Baffle Bolt NDE inspection under new Materials Reliability Program (MRP-227) guidelines for Pressurized Water Reactor Internals Inspection and Evaluation. AREVA completed the record exam of 1,088 bolts 17 hours ahead of schedule. Plus, the project was completed under the exposure estimate with zero foreign material exclusion (FME) incidents. Worldwide, AREVA has removed or replaced more than 8,700 core barrel and baffle-to-former bolts to date. Additionally, AREVA can perform inspection in parallel with bolt replacement activities, further minimizing outage time.

Internals Bolting Replacement – Clevis Bolts

AREVA performed an unprecedented replacement of clevis bolts located on the lower radial support system of the reactor vessel at a U.S. plant. To complete the underwater bolt replacement, AREVA engineers designed a unique tooling system to perform work remotely from refuel floor platforms. Lessons learned from this project will improve the efficiency of future bolt and reactor vessel internals replacements.

The project won the AREVA Vendor Award for NEI’s Top Industry Practice Awards.

Clevis Bolt Replacement

  • Proven production rates based on experience
  • All tooling and processes are based on existing bolt replacement equipment that has been used on over 8,700 previous applications
  • EDM process is used for all machining operations to avoid FME concerns
  • Improved bolt design for lower stress concentrations
  • Crimp cup locking mechanism – No welding required for installation

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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Video — Clevis Bolt Replacement
Contact Us

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