Alongside the engineering and manufacturing efforts, the company’s field implementation teams planned the complex logistics of replacing multiple RCPs during a normal maintenance outage. The company’s pump and motor field service team and Surry’s maintenance technicians completed extensive mock-up training exercises, which were integral to the planning and preparation. This also led to the development of new and improved tooling and equipment.
With these investments in planning and preparation, the replacement was a success. A key factor was close coordination among the teams from the Surry station, Dominion engineering in Innsbrook, Virginia, the nuclear energy services company’s pump and motor service center in Lynchburg, Virginia, and the company’s manufacturing facility in Jeumont, France.
Identifying & Integrating Lessons Learned
Project personnel learned several lessons throughout the process of refurbishing and qualifying the RCPs, including opportunities to integrate safety improvements, enhance outage excellence and innovate technologies in preparation for the next scope of work.
Maintaining a Clear Focus on Safety
Five RCPs were refurbished and installed without any safety issues, personal contamination events or human performance errors. This performance is attributed to the team’s rigorous focus on safety, which was the No. 1 priority during the entire project.
Using full-scale mock-ups for the RCP and machining activities, both management and crew members trained and performed all tasks based on field-like conditions. Ensuring team members experience radiation doses
well within regulated limits is a key aspect of every project plan.
Practicing critical tasks where expected radiation exposure is higher, such as removing and installing the RCP and the shield plug access cover on the mock-ups, allowed the team to explore best practices to reduce process time and to integrate new techniques that resulted in lowering expected REM dose exposure, also called achieving dose savings. REM is a standard unit of measurement for radiation dosage; it combines the amount of energy produced by the radioactive material with the medical effects of the given type of radiation.
This focus on safety resulted in measurable reductions in the radiation levels the team experienced during each refurbishment. The dose savings from the first pump to the last were 1.521 REM, equivalent to a dose savings of approximately 76 milli-REM per individual per RCP outage.
Enhancing Outage Excellence
Because timeframes for outages are decreasing at plants across the country, largely for economic reasons, the project team identified numerous ways to improve processes, incorporate best practices and develop solutions for equipment efficiency. By continually improving, the team maintained the outage schedule and stayed within budget.
Improved communication between the field and project teams was critical to the success of the project. A key lesson learned and adopted early in the process was to organize the entire project team in the same working area.
Having a unified base location eliminated communication delays and improved handoffs between teams.
In addition, remote video monitoring and communication equipment supported inspections and eliminated the need for multiple oversight personnel.
As a result, the team could provide status updates and troubleshoot issues in real time in the field with outside support.
Integrating Innovative Processes & Technologies
Improved processes and innovative technologies allowed the team to be proactive, which increased productivity and reduced critical path time and impacts to the schedule and other work groups.
Innovative solutions for transporting and installing components also improved overall project performance. For instance, the nuclear energy services company designed a shielded transport RCP cask with one hook to up-end the large component.
The cask’s smaller footprint and easy lift design simplified the process of repositioning the component, reducing polar crane and critical path time by eight hours per pump.
Engineering innovations helped configure the unique style of Kewaunee’s pumps for Surry. Flow curves, piping configurations and thermal monitoring systems all required attention. Dominion worked with the nuclear energy services company to fabricate new shafts and impellers for the pumps to achieve flow requirements.
Because of the RCP’s complex geometry, state-of-the-art digital measurement technology was used to measure the different dimensions of the pump components. Three-dimensional overlays of the new and old pumps identified possible deviations with more accuracy and speed than was previously possible through manual measurements.