System automatically detects cracks in nuclear power plants
Image care of EPRI
"Periodic inspection of the components of nuclear power plants is important to avoid accidents and ensure safe operation," said Mohammad R. Jahanshahi, an assistant professor in Purdue University's Lyles School of Civil Engineering. "However, current inspection practices are time consuming, tedious and subjective because they involve an operator manually locating cracks in metallic surfaces."
Other automatic crack detection algorithms under development often do not detect cracks in metallic surfaces because the cracks are usually small, have low contrast and are difficult to distinguish from welds, scratches and grind marks. The new system, called CRAQ, for crack recognition and quantification, overcomes this limitation by using an advanced algorithm and a powerful "machine learning" technique to detect cracks based on the changing texture surrounding cracks on steel surfaces..
The automated approach could help improve the state of the nation's infrastructure, recently given an overall grade of D+ by the American Society of Civil Engineers, he said.
"One reason we have a grade of D+ for the infrastructure is insufficient inspection," said Jahanshahi, director of Purdue's Smart Informatix Laboratory. "So we want to have more frequent inspection using robotic systems to collect data."
The nation operates 99 commercial nuclear power plants, which account for about 20 percent of total U.S. electricity generation. Aging can result in cracking, fatigue, embrittlement of metal components, wear, erosion, corrosion and oxidation.
"Cracking is an important factor in aging degradation that may cause leaking and result in hazardous incidents," Jahanshahi said. "For instance, the Millstone nuclear power station in Connecticut had an accident in 1996 that was caused by a leaking valve, and the accident cost $254 million. In 2010, the Vermont Yankee Nuclear Power Plant had an accident where deteriorating underground pipes leaked radioactive tritium into groundwater supplies, resulting in $700 million in damage."
Complicating the inspection process is that nuclear reactors are submerged in water to maintain cooling.
"Consequently, direct manual inspection of reactor internals is not feasible due to high temperatures and radiation hazards," Jahanshahi said. "So remotely recorded videos at the underwater reactor surface are used for inspection. However, recent testing has identi?ed a need for increased reliability associated with identifying cracks from reviews of live and recorded data. The results indicate that this capability is degraded by human involvement in identifying cracks, even when identi?cation should be easy."
Other automated crack-detection systems under development are designed for processing single images, whereas the new method processes multiple video frames, providing more robust results. Findings show the system outperformed two others under development.
"In contrast to other methods that only focus on detecting cracks in one image, we propose a method called Bayesian data fusion that tracks detected cracks in video frames and fuses the information obtained from multiple frames," Jahanshahi said. "Moreover, we can ?lter out falsely detected cracks and increase the reliability and robustness of crack detection by using Bayesian decision theory," which determines the probability that an object is a crack or a false alarm. The system assigns "con?dence levels" automatically assessing whether the detected cracks are real, outlining the cracks with color-coded boxes that correspond to these confidence levels. For example, if the algorithm assigns a high confidence level to a crack, the box outline is red. The processing procedure takes about a minute.
"Then, a technician could do a manual inspection to confirm that there is a crack," Jahanshahi said.
The research paper was authored by doctoral student Fu-Chen Chen; Jahanshahi; doctoral student Rih-Teng Wu; and Chris Joffe, technical leader for Non-destructive Evaluation at the Electric Power Research Institute (EPRI), a nonprofit organization funded by the electric utility industry.
Researchers recorded videos using an underwater camera system scanning 304 stainless steel specimens containing cracks and also features such as welds, grinding marks and scratches.
Future research will include work to develop a more accurate and more fully automated system using advanced simulations and computational software.
"We are currently working on the second version of the software by developing deep learning algorithms to detect cracks for this application where we have significantly improved the performance of the system using Constitutional Neural Networks," Jahanshahi said.
The researchers have filed a patent application through the Office of Technology Commercialization of the Purdue Research Foundation.
Other news from the department science
Rare gene variants identified that play a role in hereditary male hair loss
Researchers find puzzle pieces for hair loss
New approach to testing for long Covid
Blood vessels in the eye altered with persistent coronavirus symptoms
Pixel-by-pixel analysis yields insights into lithium-ion batteries
In a first, researchers have observed how lithium ions flow through a battery interface, which could help optimize the material’s design
Researchers create pioneering approaches for the detection of viral antigens
Sybodies: a revolution in biological recognition
‘Lab-on-a-drone’ sends science skyward to keep track of smelly air pollution
A low-cost 3D printed analytical IoT platform for vertical monitoring of gaseous hydrogen sulphide
Observing nanoparticles with unprecedented precision
Illuminated: Researchers investigate new physical phenomena on the nanoscale with microstructured fibers
Start-up recycles plastic lab waste into new test tubes and petri dishes
University of Bath is home to UK’s first pilot plant for recycling plastic lab waste
Gotcha! New technology speeds up bacterial testing in food
A promising technology that could potentially revolutionize the process of testing bacterial viability in food
Benchtop NMR spectroscopy can accurately analyse pyrolysis oils
More accessible analysis could help develop the potential of bio-oils as an alternative to fossil fuels
Structure formation during freeze casting filmed in 3D and real time
Freeze-cast materials can be used for many applications: as battery electrodes, catalyst materials or in biomedicine
Virtual lab calculates optimal lubricant composition
Extending lubricant lifespan: Sensor system developed for real-time monitoring
Unpacking the smart way
How Incoming adenoviruses change their chromatin structure for efficient gene expression
New "radar" detects active cellular destroyers
Study provide an unprecedented look at the actors involved in the dynamic changes of our protein balance
Most read news
Benchtop NMR spectroscopy can accurately analyse pyrolysis oils
Scientists use quantum device to slow down simulated chemical reaction 100 billion times
What happens in femtoseconds in nature can now be observed in milliseconds in the lab
Fondant under the magnifying glass
New insights into the properties of sweet coating: The results could be used to optimize the industrial production process in the future
More news from our other portals
Major breakthrough in the development of electric vehicle batteries
New study finds ways to suppress lithium plating in automotive batteries for faster charging electric vehicles
Cells with an ear for music release insulin
For the first time, researchers are using music, including Queen's global hit "We will rock you," to stimulate insulin release from cells
Clean water from fog
A property known as photocatalytic memory ensures that this also functions when skies are overcast and at night
Research shows table salt could be the secret ingredient for better chemical recycling
Table salt as the key to the plastics recycling revolution?
Microbe of the Year 2023: Bacillus subtilis – for health and technology
Already, Bacillus subtilis is indispensable in many industries, and many more innovations are expected
Green, sweet and crisp - New apple variety Pia41 approved
The apple bred at the Julius Kühn Institute receives variety protection
Leipzig-based start-up converts CO₂ into green chemicals with patented plasma catalysis
CO₂ recycling as a useful complement to carbon capture and storage
Younger generation gets sick earlier and more often than older generation
In spite of their advanced age, they are in the middle of life, healthy, active and mentally alert – they are referred to as the “young old”
Sugar: Small increase in production despite record prices
EU sugar market more than in need of reform to keep medium-sized processing companies competitive
New battery holds promise for green energy
Redox-flow battery eliminates costly and inefficient membrane
How sleep deprivation can harm the brain
Sleep deprivation decreases the amount of a factor that protects neurons
A Second Life for Electric Car Batteries
Scientists develop a decision model for retired lithium-ion batteries
A microchip for Parmigiano Reggiano cheese
Consorzio del Parmigiano Reggiano, p-Chip Corporation, and Kaasmerk Matec Partner to Launch Breakthrough in Food-Safe Digital Tracking Technology
World record: World's longest-range electric car comes from Munich
Electric car drives over 2500 kilometres on a single battery charge
A whole new order of bacteria could hold the key to improving biogas production
The discovery was made by researchers from Germany, Spain and the Netherlands
Green methanol for shipping and industry: € 10.4 Mio. for the "Leuna100" project
A consortium of two Fraunhofer institutes, DBI-Gastechnologisches Institut Freiberg, Technical University of Berlin and C1 makes industrial history at the Leuna site
How to inactivate common cold viruses
In the cold season, cold viruses are everywhere. But we can do something about it
How minimal genetic differences can turn healthy food into a deadly danger
You are what you eat - this old saying could take on a new dimension according to latest research results
At which age we are at our happiest
An evaluation of over 400 samples shows how subjective well-being develops over the course of a lifespan
Straws and disposable tableware: Also made of paper often with harmful chemicals for the environment and health
The supposedly better alternative is often not better at all, scientists emphasize
New lithium battery with simple production and high safety developed
"This study underscores the importance of molecular structure design in creating effective additives for quasi-solid-state electrolytes"
New compound unleashes the immune system on metastases
A new nanocomplex renders a tumor harmless – and, on top of that, it trains the immune system to detect and eliminate metastases