Aquilex Sets the Standard for MSIV Repair
Plant type: nuclear

Client Challenge

During the plant’s routine inspection, MSIV outboard and inboard valves did not pass Low Leak Rates Tests (LLRTs). Since LLRTs cannot be determined prior to an inspection, valve replacement or refurbishment became the critical path project in the resulting outage. Valve replacement was determined to be cost-prohibitive, so the plant required rapid valve repair. And, because high internal radiation doses expose workers to continuous dose, first-time LLRT approval was an absolute necessity.

Aquilex Solution

Knowing the possibility of LLRT failure and required rebuild of MSIVs during the refueling outage inspection, the plant brought in a standby of personnel and equipment. Aquilex WSI Nuclear Services was selected based on a number of factors:

• Complete refurbishment capabilities of nose cone modification, poppet repair, flange seal buildup, rib and seat replacement and valve body repair
• Significant experience, with approximately 30 MSIV refurbishments in the three years leading up to the outage
• Technology and expertise demonstrated through development of the valve mapping tools and technology responsible for the most sophisticated approach to MSIV repair
• Most experienced and skilled craft in the industry

To address the extremely tight dimension tolerances of valve refurbishment, Aquilex WSI Nuclear Services developed a proprietary mapping program to map hundreds of points for dimension and make sure they lined up precisely.

Results

In just seven days, Aquilex WSI Nuclear Services was able to perform actuator repairs, seat and guide replacement and body repairs. Upon completion, the valves were put in “better than new” condition and the LLRTs were the lowest that the client had ever experienced on their MSIVs.