Spanning the realm of the nuclear power industry, David Wilhite’s experience is vast and storied; whether the job at-hand is supplying parts, conducting onsite plant modifications or designing the next-generation power plants, David has worn a multitude of hats throughout his career. On a sunny day in Texas, Pump Engineer had the pleasure of sitting down with David to gain insight into an end user’s perspective on turning an industry’s past challenges into future solutions.
Origins and Opportunity
David’s interest in the industry initially emerged in the way that many new discoveries do: opportunities presented after graduating. Since then, however, the work to follow has been anything but linear. “Everything is different,” says David. “Whether it be working with a heat exchanger, valve, pump or a pressure fit, everything is a unique challenge.” Across his experiences, David notes that what he enjoys most is the element of diversity. “It is not necessarily the same calculation or boilerplate item repeated time and time again.”
When it comes to David’s professional journey, he is backed by a resume packed with variety. Having begun his work as a project engineer at Nuclear Logistics, which involved writing test plans and overseeing test equipment for the nuclear-related quality assurance program, he moved to design work and site modifications. This work encompassed anything from replacing pumps affected by chemical corrosion to reviewing the heat exchangers in cooling water systems. From there, he moved into providing consulting expertise on the performance limitations and failure analysis of clients’ products, employing strain gages and oscilloscopes to isolate a given product’s particular stresses.
Trial, Error, Repeat
The rewards of the work do not come without their challenges, of course. The personal research involved in catching up to speed on a particular sub-issue while maintaining a quick turnaround is among the heftier tasks, David notes. “Sometimes, the challenge is learning a programming language in order to write the script and automation needed for a particular analysis at a particular time,” he shares. “It is a learning curve when you have to conduct a calculation analysis in time, while also learning the entire infrastructure or model behind it to be able to properly apply it.”
As is the case with most complex industrial applications, David has encountered his share of troubleshooting pump-specific obstacles. He notes that increasing flow rates or transfers is a common goal in pump processes and, as such, the impellers are highly analyzed to reach better performance — while maintaining the same body and frame. This involves changing out the cover to get a different curve characteristic, in addition to the full analysis required of such a process.
“There are different power groups at play,” David says. “You may have to parallel systems or check the flow of balancing between two different loops, depending upon which pump is running at the time, as well as the transients flipping between them. In one instance in David’s work, a case crossed his path in which hydrazine injection pumps were added. “Because this is a very high pressure, low volume pump and hydrazine is such a toxic chemical, this displacement pump was doing everything that it could,” David explains. “But the maintenance guys were having to go through and rebuild the seals every three weeks.”
The case at hand was a particularly high-managed item, and David put his efforts into researching the seals, along with other pumps and alternative solutions. Eventually, it was decided that they would employ more of the same pump in parallel. “I always have a backup pump,” David shares. “But if one pump is broken and one is running, we are able to rotate them back and forth. “From a design side, we basically made it for a quick release that the maintenance guys could take out easily. Since they have done it so often, they were very good at it.” Instead of trying to make something overly robust, David says, he incorporated a disposable perspective in order to aid in the maintenance process. “That is what the maintenance guys wanted, so that is what I let them have. I am there to try to make their lives easier.”
Alongside technical challenges, however, the looming theme of obsolescence is one that cannot go ignored. “It is something that we are constantly encountering in the industry,” David expresses. He explains that most nuclear power plants were constructed in the 1970s and 1980s, and that the original plants were given a 40-year life. Those plants that could prove that they were well- maintained over those 40 years were allowed to apply for a 20-year extension, which would provide 60 years of life — and, to be granted those extra 20 years, major pieces of the plant would often have to be replaced entirely. However, many manufacturers did not support that obsolescence over the 60-year timeframe. Many times, equipment had to be reengineered, reverse engineered or redesigned.
Regarding the standards at play in such a process, David indicates that the nuclear industry has a unique Quality Assurance (QA) regulatory program executed by the Nuclear Regulatory Commission (NRC), similar to ISO. However, the one specific to the nuclear industry has included several unique elements for purposes of traceability, manufacturing oversight and QA testing that have different expectations than a traditional ISO program. David notes that many of the manufacturers no longer maintain the nuclear industry QA program, so they would “run the matter through Nuclear Logistics, put the QA umbrella on it for the oversight and then supply it to the power plants under the nuclear quality program.” This was being done when it came to the reengineering of obsolete parts or finding the equivalent replacement, as well as redesigning systems to accommodate the redesign itself. “That is where I wore various hats in the process,” David says.
As for what David considers to be the biggest risk of obsolescence in new plant design? Electrical control. “Going into digital controls has been a really hot-button item within the nuclear industry,” he explains. “Even if you have a digital control system that’s state-of-the-art today, how can you get a 60-year life out of it?” David is quick to admit, however, that the evolution of technology within the industry has also provided its fair share of benefits. Motor-and-air operated valves have been particularly convenient to operators by allowing them to remain in a central control room while controlling the various valves throughout the plant, which especially comes in handy in harsh environments.
Propelling From the Past
Despite the advancements and developments most relevant to the nuclear industry today, it is worth noting that large-scale events of the past such as Fukushima have contributed to a surrounding stigma, which saw the shutdown of multiple plants; especially in Germany. Nevertheless, new designs and plant openings have persisted despite the publicity. “I still believe that the designs are completely safe within the nuclear industry,” David affirms. “It is an excellent technology. Economic challenges are faced because it takes large amounts of capital to construct the plants in the first place, and that has been a downfall to many construction-related projects.” David emphasizes his desire to clarify that the nuclear-based energy technology itself is not the safety problem when it comes to construction; noting that the massive capital investment is the true culprit. He adds that once the plants are up and running, the day-to-day maintenance on them is typically very low, and the amount of power and electricity within a small footprint is tremendous.
The clean energy involved certainly makes a case for itself, as well. “There are zero emissions to a nuclear power plant. It heats up water and provides electricity. That’s all it really is: another water heater, just on a very large scale. The nuclear safety is still paramount, and there have been significant improvements over the years.” With regards to Fukushima, David mentions that the entirety of the USA, and especially the NRC, evaluated all emergency safety plans and rolled out additional safety infrastructures (FLEX). “They have auxiliary emergency equipment in centralized locations throughout the U.S. that they can dispatch from a remote location. In the event that local assets and resources are damaged from some type of storm, they have the capacity to deploy these remote assets,” he explains. David poses another question to take into consideration when evaluating the plant-radiation dynamic. “Nobody died in Fukushima due to radiation,” David says. “Fukushima was a terrible accident involving a lot of recovery and clean-up, but there were zero deaths due to radiation from the plant.”
Furthering his point, David provides the example of the Three Mile Island accident, the well-known comparison in the U.S., alleging that no one died from radiation at that site, either. “There was barely measurable radiation at the property boundary. It was actually a huge success of the power plant design,” David shares. “The operators made various mistakes, so it was a tremendous warning lesson for all the operators as to how to run a power plant. Yes, the core melted upon itself, but nobody got hurt because all of the safety systems were designed in such a way that it would fail to a safe state. So, these were successes, not failures.”
Forth to the Future
Looking toward the future, David considers how far the industry has come within the nuclear renaissance of the past ten years. Regarding this shift with optimism, he says: “There is a lot of hype and staffing for those opportunities, as well as construction challenges for trying to build a lot of the nuclear power plants. But I think the technology is very solid for what is there.” The reach of these developments resonates globally, as well, with countries like China teeming on the verge of starting up their next new nuclear power plant by the end of this year, according to David’s estimations. “Keep your eyes peeled. The developments to come are going to help prove that these new technologies are viable and working.”
All things considered, it is palpably apparent that David’s belief in the industry is rooted in nothing short of steadfast conviction. Having stood in the center of the changing tides, David knows that though the industry has seen its ebbs and flows, what matters most is that it has seen them through.