​Expertise Vital in Hydraulic Repair for Nuclear Power Plant

Power plant interior with many pipes and hydraulic systems

When a nuclear power plant needed help diagnosing issues with one of its emergency hydraulic systems and making the necessary repairs, they called in the experts at DHI for help. Troubleshooting a nuclear power plant is fraught with complications due to its highly regulated environment, but Brian Devine was on the job. A leading expert in hydraulics, Devine was able to identify why the breakdowns were occurring and how to work through the inherent challenges of performing hydraulic repairs and maintenance in a highly regulated environment. 

Emergency Hydraulic System Repair Requires Expert Consultation

DHI was called in because the seals of the plant’s hydraulic systems had failed after two months — even though the seals would typically last for up to 15 years. Something was causing problems in a system that needs to function perfectly in the event of an emergency, and they needed to know why and fix it post-haste. With the clue of the mysterious, rapidly-wearing seals as a starting point, they turned to the experts at DHI to diagnose the cause and help develop a long-term solution with minimal disruption to plant operations.

The Nuclear Regulatory Commission (NRC) pays close attention to how plants are regulated and monitored, and for good reason. Unlike hydroelectric power plants, you can’t test multiple scenarios to find the best options. If the systems of a nuclear power plant are not perfectly aligned, it can cause unsafe conditions and trigger power outages to the surrounding neighborhoods. It can also lead to hefty fines from the NRC.

The Delicate Art of Nuclear Power Plant Hydraulic Systems Repair

In a nuclear power plant, precision is critical to the success of the operation. The cylinders of a nuclear power plant are essentially the same as any hydraulic system, but nuclear power plants are delicate and cylinder repairs cannot be performed incrementally with frequent pauses to reactivate and deactivate the system for additional assessment. 

There were dozens of engineers on the client-side working on this problem before DHI was brought in. The professionals who installed the systems had already performed system failure analysis and strategized solutions. DHI was called because of the reputation they’ve built for getting it right the first time. When Brian Devine was brought in, he did the research and reached out to manufacturers. Due to his extensive expertise in hydraulic equipment, he knew that the success of this repair would depend on making the most accurate calculations possible and wanted to ensure that his information was correct— proving that even experts double-check their work.

Applying Decades of Experience to Solve Nuclear Power Plant Hydraulic Failure

Devine was able to identify several key issues that contributed to this failure. For one, the steam generated was so turbulent it triggered the cylinder to oscillate at a rate of 17hz. In addition, there was a side-load due to the spring that was mounted on the rod end of the cylinder that would (fail close) the cylinder in case of an emergency that was loading the cylinder off-center. Between the high oscillation and the movement of the cylinder, there was a significant amount of damage to the cylinders (the rod, rod bushing, piston, and bore of the cylinder were scored).

The seals were a loaded lip style and prevented oil from passing in the reverse direction, causing them to lock-in fluid between the two piston seals causing the seals to be loaded in both directions at all times, there was wear through the seals due to the constant friction. The solution was to rectify the side-load due to the spring (mechanical issue) and replace the seals with a non-loaded lip urethane seal. This would eliminate the seal from working in both directions and allowing oil to pass in the reverse movement. Eliminating the locked in pressure between the two seals.

Diagnosing the intricacies of a nuclear power plant is no easy feat. The value of DHI is access to decades of experience designing, troubleshooting, repairing, or upgrading hydraulic systems to meet the needs of almost any application. It’s why you can count on DHI to apply the same degree of dedication and precision to detail to your company’s hydraulic system.

Struggling with hard-to-solve hydraulic problems? Contact Devine Hydraulics today and get the help you need.