Nuclear Energy Insight
Summer 2012—If you want to talk about innovation, talk to Exelon’s Jim Tusar.
He took home two nuclear energy industry Top Industry Practice Awards in this year’s competition—bringing his total to seven.
Innovation should be a priority “from the top down,” said Tusar, a fuels manager. In addition to entering the industry’s Top Industry Practice competition regularly, Exelon fosters innovation through its corporate programs. “Senior management really stands behind innovation, so the employees are always looking for ways to do things better,” he said.
“I have a passion for creativity. I really like to solve problems and try to exhibit continuous improvement,” Tusar said. “When you have that passion to solve problems, coming up with ideas comes naturally.”
One of Tusar’s accomplishments this year was winning the GE Hitachi-sponsored award for a program to lessen moisture in steam generators, making the process more efficient, saving the company millions of dollars every two years—and reducing employee’s already low exposure to radiation.
His second award recognized improvement in reactor fuel that will save Exelon more than $22 million across all of its nuclear energy facilities.
He said the projects were done in collaboration with Exelon’s fuel supplier, Global Nuclear Fuel. “We had a vision. We knew what we wanted to solve. We had open and honest communication throughout the project.”
This kind of innovation occurs continually throughout the nuclear energy industry. The growing demand for electricity is driving innovation in everything from advanced reactors to high-efficiency nuclear fuels and cutting-edge technologies that improve safety and efficiency at nuclear energy facilities.
No matter how long a reactor has been producing electricity, operators are looking for improvements in performance and safety. The Nuclear Energy Institute’s Top Industry Practice Awards focus attention on some of the best ideas. Winning entries include a laser and underwater camera system that monitors reactor components, computer modeling software for fuel assembly alignment, and a fleet of tiny robots that can navigate the thousands of tubes in a steam generator.
Exelon Nuclear developed a way to accurately identify deteriorated components inside a reactor so they can be replaced quickly and safely. Plant workers previously had two options for measuring hard-to-reach components, using simple tools or designing custom tools to fit around each component. Seeking a better way, an Exelon team worked with Newton Research Labs to combine green laser light technology and an underwater camera to capture data. Software then creates a three-dimensional model from the data.
Exelon also uses new computer modeling techniques to ensure that nuclear fuel assemblies are properly aligned when they are loaded into the reactor. A typical fuel assembly is 14 feet long, weighs up to 1,600 pounds and is maneuvered by a remotely operated bridge that straddles the open top of the reactor vessel during refueling.
Workers generally inspect the assemblies using binoculars or underwater cameras. But to improve accuracy, Exelon partnered again with Newton Research Labs to develop a system that employs a high-resolution camera to “map” fuel assembly positions and determine their alignment. The resulting map is compared to ideal positions established by plant engineers. A computer then analyzes the data and displays the results with a color-coded image that shows how well each assembly is aligned.
At other plants, new applications of robotics are revolutionizing the way nuclear energy companies maintain some major components.
Duke Energy’s Oconee 2 in South Carolina is a pressurized water reactor. Heat produced by splitting atoms in the nuclear fuel is transferred to create the steam that drives the turbines to produce electricity. The plant’s two massive steam generators contain 31,000 tubes, all of which have to be inspected to ensure structural integrity. The standard technique, known as eddy current testing, involves sending an electrical current through portions of the tube material. The resulting signal allows workers to identify tube defects, but analyzing the data and accessing the tubes for inspection is difficult.
Enter the ZR-100, a small robot produced by Zetec Inc. Weighing less than 35 pounds, the robot crawls nimbly through the maze of tubes inside the steam generator, gathering eddy current data as it goes. Multiple robots can work inside a single steam generator thanks to onboard telemetry that helps avoid collisions.
Duke Energy also has captured attention as an industry leader in applying state-of-the-art digital technology in nuclear safety systems, replacing the older analog systems. The company’s Oconee nuclear energy facility was the first in the United States to undergo a digital upgrade that installed microprocessor-based modules for two systems used to shut down the reactor automatically or operate key safety systems such as emergency cooling water injection. The new system also detects bad sensors and can ignore false readings.
For the digitization project, Duke Energy captured the Best of the Best Award, which is given to a TIP winner whose entry rises above the others by demonstrating exceptional leadership in scope, safety enhancement and usefulness to the nuclear energy industry.
Innovative ways to use passive systems— which require no electricity or human intervention—can enhance safety and efficiency in certain applications.
Liquid-filled components at nuclear power plants must be monitored to ensure that unacceptable quantities of air or other gases do not accumulate. South Carolina Electric & Gas developed a straightforward way to monitor the air level and a direct method for venting any gases. This “air-trap” requires no electricity to run. Instead, magnetic floats measure the air-water level.
The traps eliminate the human error inherent in gathering and interpreting data ultrasonically, and the externally mounted indicator is easy to access and read.
“Innovative ideas like those highlighted by the TIP Awards have helped America’s nuclear energy facilities increase electricity production by 37 percent since 1990,” said Tony Pietrangelo, senior vice president and chief nuclear officer at NEI.
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Read more articles in Nuclear Energy Insight and Insight Web Extra.