Technological leaps and bounds have been made in the world of nuclear reactors since Idaho National Laboratory’s (INL’s) inception as the National Reactor Testing Station in 1949. But as many good INL scientists and researchers know, there is still a world of potential growth out there. Vivek Agarwal is one of many talented researchers and inventors working on research concepts to streamline processes in nuclear power plants and create better overall efficiency.
“Within the nuclear industry, we are working on solutions that utilize advanced technologies to automate activities that are currently being performed manually by skilled laborers, to enable a business model that is technology-centric. With that objective in mind, INL is working on these projects,” Agarwal explained.
Within nuclear power plants, there are a wide range of manual valves used for purposes such as equipment isolation, process control, high pressure isolation, flow control of service water, and main steam/feed-water isolation. Generally, nuclear power plants require two or more people to go out and complete independent/concurrent verification on these valve positions within the power plant to ensure they are working properly and are in position as described in a procedure. Not only is this cost ineffective and time consuming, but it also leaves room for human error and potential hazards.
Agarwal and his team of researchers began searching for solutions to these problems within the commercial industry, but they didn’t discover any solutions that met their evaluation criteria for nuclear. All of the available sensors that could allow workers to be updated on a valve’s position and condition without having to perform any manual work required modification to valve design to insert the sensor.
“Once you modify the valve design provided by the original equipment manufacturer in nuclear industry, it requires recalibration and recertification. We were looking for a solution that can easily be installed onto the valve body without modifying its design, thereby eliminating the need to recalibrate and recertify,” Agarwal stated.
His team has developed a wireless valve position indication sensor system that can be retrofitted to different manual valve types. It comprises a passive magnetic sensor that does not require any power; only the electronics used to transmit the data need power. Additionally, this sensor system transmits more valve position information than the available commercial options.
As Agarwal said, “Most solutions in the market will give you binary information: whether the valve is fully open, or fully closed. They don’t give you intermediate position on a continuous time basis. With our sensor system, as you operate the valve, its position is transmitted to a remote location, so the field worker can monitor what is happening in nearly real time.”
Additionally, the technology allows for an online valve calibration check and evaluation of the health of the valve without direct inspection by field workers. When valves degrade, this can cause a shift in the reading, and the technology provides operators with this information, which in turn, helps them understand what, if any, type of maintenance it requires. Ultimately, Agarwal hopes that the sensor system will be radiation hardened and seismically qualified, allowing it to be installed in radiation zones, so field workers do not have to suit up and go into such zones to verify valve positions. Not only does this prevent exposure, but it also prevents the generation of nuclear waste (in the form of disposed radiation suits). The sensor system also addresses issues such as electromagnetic interference (EMI), cybersecurity and power consumption.
“What the nuclear industry is very concerned about is EMI of digital devices being put into nuclear power plants,” Agarwal explained. “Our sensor system is certified by EMI engineers, and so far, they have declared our system is qualified. Another question that comes up is related to how much power consumption you deal with, and how frequently you have to change the battery. We are looking at self-powered solutions using energy harvesting techniques that are readily available in nuclear power plants, like thermal or vibration energies. There are plenty of options within nuclear plants.”
In terms of cybersecurity, the sensor system supports one-way communication, so no control action can be done on the valves using this technology. All the sensor system does is read the valve position and transmit that data to a remote location, which means the valve itself does not actually receive any information and thus cannot be controlled or manipulated.
Agarwal and his team participated in the Energy I-Corps program, which prepares researchers and inventors to share their technologies with the marketplace. Through this program, Agarwal’s wireless valve position indication sensor system received significant interest from several organizations. Exelon Generation Company partnered with INL through the U.S Department of Energy’s Technology Commercialization Fund to advance the technology readiness level to 8, and will provide an opportunity to perform field evaluation of the technology. Agarwal and his team have visited and communicated with the Nine Mile Point Generating Station and the Calvert Cliff Generating Station. “We are in the process of figuring out what kind of modifications are needed to install the sensor system on identified valve types at each plant,” Agarwal stated. During this field trip process, Agarwal discovered that nuclear reactors have strong need for this sensor technology. “Sometimes these valves are located in hard to reach locations and are operated using a chain. This presents a challenge on operating those valves and obtaining accurate valve position. This technology will enable position indication of such manual valves.”
Agarwal’s team also presented the technology at the DOE National Accelerated Pitch Competition in 2017, where they received feedback on their technology from a group of venture capitalists, in what Agarwal described as a “Shark Tank” situation. Their team placed second among the nine competitors, which gave them a nice boost of confidence, knowing that their invention had received admiration from a group of Silicon Valley businesspeople.
In addition to a patent application for this wireless valve position indication sensor system, Agarwal has filed a patent for a data analytics technology, which, in his words, “takes all the data that comes out of an acoustic sensor system and analyzes it using advanced signal processing and machine learning techniques.” The bulk of the rest of his research involves using the information gleaned from data analytics to understand the state of the plant asset he’s investigating, diagnose the cause of any degradation, and provide an accurate prognosis. “With the diagnosis and prognosis in hand, the next big aspect is risk assessment. How can we evaluate the risks of any actions we take on the plant asset now that we have information on its health?” Agarwal explained.
For his extensive research, Agarwal was honored with INL’s Early Career Exceptional Achievement Award in 2016. He believes his success and recognition is attributable to having a strong team, sustained funding, good collaboration and mentoring. “I could not have done this alone,” Agarwal stated. “I am honored and very thankful to my manager, who decided I was worthy of recognition and nominated me.”
Agarwal’s advice for aspiring young scientists is to be sure they step outside of their comfort zones, and to not be afraid to take risks and make bold decisions. He was unsure whether he should take the time to go through the Energy I-Corps program, but has never regretted the decision, as it has, in his words, “transformed his research outlook significantly.”
“Do something new that is not your strength,” Agarwal advises. “You might succeed, or you might not, but what that experience will teach you will be incredibly impactful for your life going forward and helpful for all the decisions you might make. So take a risk, especially early in your career.”
