It Begins With Training

Quality Magazine –

In today’s advancing nondestructive testing world, NDT training is a crucial part of obtaining certifications, job satisfaction and career growth.

Qualified NDT(Nondestructive Testing) professionals are in high demand in the progressive petrochemical industry, although NDT is a career field that has little to no exposure within the general population. As training facilities emerge to aid in filling the numerous job openings, available exposure to this very rewarding career is beginning to escalate in popularity.

Our NDT personnel require more training to maximize the effectiveness of operation with these ever-changing technologies. NDT is a growing career field, projected to be worth $1720.96 million by 2020, according to Sys-Con Media www.sys-con.com/node/3046174. And with the proper training and certification, technicians can help NDT technology grow by increasing safety and environmental awareness along with satisfying demands for high quality services.

In today’s advancing nondestructive testing world, NDT training is a crucial part of obtaining certifications, job satisfaction and career growth. A great deal of responsibility is placed on our NDT technicians who help keep our aircraft, trains and automobiles operating safely, and our pipelines and chemical plants from having failures and costly down time, with advancements in the equipment and products produced by these industries. The need for a good quality system in each industry is a must to manufacture and maintain functional safe environments for their particular product in each industry. The NDT technicians with proper training will be able to determine which discipline of NDT is best to use for the isolation of anomalies present in the materials under examination. Training can provide the NDT technicians with the theory of how each method works and the advantages and limitations of each method. Training can take the NDT technicians from the theory of each method and teach the technicians how to employ that theory in their day to day inspections to maximize the quality of inspections and be better prepared to deal with special circumstances that often occur in the day to day use of each method.

NDT equipment and methods are constantly changing with new advancements in technology. The basic theory of each method has not changed but how we employ that theory is much more sophisticated. This has dramatically changed how training is performed. With more and more of our instruments being computerized, the requirement to have knowledge of the basic principles of NDT becomes apparent daily in the classroom. Specialized advanced training for use of technological driven instruments is more focused on the computed aspects of each method than the basic theory at this point in the training. Most specialized advanced courses require a prerequisite of training in the basic discipline prior to the advanced course of instruction. With these advancements, an increased amount of knowledge in that particular method is required, leading to some NDT technicians specializing in those particular methods of inspection.

A well trained and accomplished technician should be able to assess the part under examination and recommend the best method or methods to which the inspection should be performed. After completion of the inspection, if anomalies are present the technician should be able to ascertain the type, approximate size, and shape of the anomalies and provide a detailed report of the findings. As the technician gains more history within a particular industry the technician should be able to asses high problem areas to each component under inspection based on the component’s function, type of material, temperatures, pressures, and any chemicals present. The technician should readily recognize any problematic areas that present unusual circumstances that may require additional methods to accomplish a quality inspection.

To achieve this level of competency in a technician it begins with training.

Training is a two prong approach which consists of a knowledge base covering theory of process and on-the-job training covering the practical use of each inspection process. Beginning with the knowledge base ASNT (American Society for Nondestructive Testing) issues the CP-105, which in its content is the topical outline for multiple methods covering the subject matter that should be addressed in the training of the entry level technician. The outline of the CP-105 is very beneficial to ensuring all trainees receive the same information; the training should be more structured around the industry that the trainee will be exposed. The training should keep the trainee engaged and inquisitive. The training should include how the theory of each method is applied to the practical inspection. How the indication was formed is the fundamental knowledge required to provide a proper assessment of the inspection performed. Without the ability to transition the theory to the results of the inspection performed, technicians are limited in their ability to address resultant abnormalities. This transition of knowledge to practical application should start in the initial training and continue throughout the technician’s career.

With the introduction of the computer and internet, NDT training can now be achieved by classroom training supplied by an instructor or by web based tutorials. Advancements in software allow instructors to answer the students’ questions online in one-on-one Q&A sessions, increasing the quality of training through computer based training without limiting the quality of the training session.

On-the-job training is where the technician starts to employ the knowledge gained into practical hands-on testing under the supervision of an experienced technician. This allows the technician to perfect the skill set through practical utilization in the field without sacrificing the quality of the examination. This will allow the trainee to begin to build historical information directly related to the industry where the technician is involved, while also gaining some of the knowledge base and history from the experienced technician supervising.

Quality of products is the foundation of all processes in the world. Without good quality products planes would cease to fly, trains would not move, oil and gas could not be produced, limiting automobiles’ movement. NDT technicians aid in ensuring that these products are made correctly and they check the quality of products throughout the service life, while allowing the product to remain in service. These checks allow for increased production of end products through minimizing lost production time and allowing for scheduled maintenance times or providing increased knowledge of replacement intervals.

Safety is improved by ensuring the quality of the component in the processes. Failure of a component can result in catastrophic damages to property and personnel. All component failures cannot be removed from occurring, but with increased inspections can be drastically minimized. This saves lives and property while minimizing unscheduled process downtime and increasing production of end product.

With the ever increasing demand for trained NDT technicians, increased quality requirements of products, higher demands for products, and tighter environmental safety controls, training of NDT technicians will become even more demanding in providing quality technicians to the work environment quickly and efficiently. Doing so means that the effectiveness of the training is ensured with each technician trained.

All of this begins with the proper training of an NDT technician. Training is the base foundation of a technician, and provides the technician with the knowledge to ensure the components examined are of the quality to maintain serviceability safely. A good structure is only as good as the foundation it rests on.

A highly trained technician is an ever increasing valuable asset.

Nondestructive Testing and Inspection

We are more reliant on high-tech inspection techniques than ever. Take your inspection program to a higher level.

Shortly after beginning the takeoff roll on a scheduled flight from Pensacola, Florida (PNS) to Atlanta (ATL), on July 16, 1996, a McDonnell Douglas MD-88 experienced a catastrophic, uncontained engine failure of the No. 1 engine. Debris from the engine’s front compressor hub penetrated the cabin, killing a woman and her son and injuring two siblings. The accident investigation determined that maintainers had failed to detect a pre-existing crack during a fluorescent penetrant inspection method, and that the maintenance operation lacked protocols to ensure vigilance during such procedures.

While the borescope enabled technicians to see inside a jet engine, it became apparent early in the jet age that once you saw a crack, you were already too late. Dye penetrant inspection along with magnetic particle and fluorescent particle methods were developed, opening up new capabilities for maintenance technicians to detect cracks. Collectively these techniques were categorized as nondestructive testing (NDT).

Still, flawed inspections have resulted in fatal accidents including the Aloha Airlines cabin failure in 1988 and the crash of a DC-10 in Sioux City, Iowa, the following year, underscoring the need for better NDT tools. Aircraft manufacturers, in coordination with aviation regulatory agencies, recognized that these inspections needed to be performed by specialists.

So, when your aircraft requires specific NDT inspections, you not only need to find an authorized provider, you also must find one who can actually return the aircraft to service. This becomes extremely important, especially if a Service Bulletin (SB) or Airworthiness Directive (AD) makes an inspection necessary in a short timeframe. What follows are some tips on how NDT systems work and how to apply them to your aircraft.

See What Cannot Be Seen

In the aviation lexicon, two of the most-despised words are “leaks” and “cracks.” While the former have the decency to let their presence be known, cracks are insidiously stealthy, and by the time you find them you are already too late.

For metallic components, stresses deform the molecular bonds within and create slip bands or tiny creases in the microstructure. Over time, these bands weaken the bond so much that they let go, much like a zipper opening. Crack detection is critical to continued airworthiness, especially for life-limited items. Discovery can ground the aircraft and result in lengthy and costly repair. Other less-sensitive areas may allow some cracking but will require repetitive inspection to ensure crack growth is within acceptable limits.

While penetrant inspections assist in detecting surface cracks, they cannot reveal trouble below. In addition, it has been shown that improperly applied penetrant can actually hide cracks. The most-common and effective method for detecting subsurface cracks is the eddy current method.

This method induces a magnetic field and a probe measures its strength and impedance to detect corrosion, cracks and other defects. The eddy current inspection works on all conductive materials and requires a calibrated test standard to compare the material being tested against. This method also can detect material heat treat and surface condition. It takes extensive training and expertise to ensure that the results are properly diagnosed; in many cases technique for applying the field and probe are critical.

For composite materials, the multi-directional layers of laminate are resistant to cracking, provided that bonding integrity is maintained. Detecting “disbonds” is of keen importance, since the strength of the affected part is determined by the number, type and shape of the defect. One simple method of detecting disbonds is the “coin tap” in which the material is gently struck with a metal object and the inspector listens for a telltale dull thud. Helicopters have been equipped with composite blades for decades, and coin tapping them has shown that method’s efficacy to be extremely subjective, influenced by both the environment and the inspector’s perceptiveness.

Thanks to advances in medical technology, ultrasonic testing (UT) is now often used for detecting bond voids and other defects in composites. This method uses high frequency sound waves to paint a picture of the material in a process much like sonar. The sound wave is bounced off of a surface and by measuring the speed and intensity of the return, the operator can determine if there is an anomaly within. UT also can be used to measure thickness.

New testing technologies emerging to meet the rapidly expanding field of composites include infrared and thermal imaging. Heat transfer through an object can be indicative of disbonds or water entrapment. The thermal camera can detect minute changes in temperature and enhance the display to pinpoint a problem. In addition, microwave and laser-based systems currently under development set up uniform heating of a surface and the optics see how the surface reacts.

A Great Responsibility

The ability to detect potential material failure is a huge benefit to many other industries besides aviation — manufacturing, energy generation and the medical field, among others. Those entrusted with making those discoveries require a high level of training, experience and integrity. The most widely recognized and accepted standard for NDT technicians is the National Aerospace Standard 410, Certification & Qualification of Nondestructive Test Personnel. Based on MIL-STD-410, the training, techniques and certification regime are laid out so all can easily follow. The American Society for Nondestructive Testing also provides guidance and training standards such as the ASNT Standard Practice SNT-TC-1A.

There are four levels of Technician Certification — Trainee, Level I (Limited), Level II (still requires supervision) and Level III (the highest level, also known as the Responsible Level III). Prior to certification, the trainee works under the supervision of a Level II or III certified technician to gain enough experience to pass a test and achieve a Level I rating. Acquiring a Level II certification requires more hours of classroom work and supervised experience. The person with a Level III certification is considered both highly skilled and supervisory, and it is the only level allowed to conduct the required classroom instruction.

In the U.S., the FAA does not recognize the NDT technician as qualified to return an aircraft to service. This puts the maintenance manager or senior technician in a quandary, since returning the aircraft to service requires a positive inspection, but the person who actually performed the work cannot make the logbook entry. While it may be possible to train an A&P to be an NDT tech, it is very difficult to maintain the number of hours and experience required to achieve a Level II or III certification necessary to complete the inspection.

For a maintenance manager, it may be difficult to justify developing and maintaining in-house NDT capability. “It makes sense to have NDT in-house if you are having issues with vendors doing your work,” said Dave Sheehy, director of Aircraft Maintenance, Pro Airways, Plymouth, Massachusetts, who added that having NDT inspection capability within your operation can make good sense, especially if the vendors’ performance is unsatisfactory.

“I used to send main wheels out for overhaul. After having repeat issues with three different vendors, we decided to bring the overhaul and build-up of these wheels in house,” he recalled. “I was previously trained to Level II, so it was a matter of finding a Level III, training for recurrency, and adding the capability to our repair station. This was a long, involved process [more than a year]. Happily, we have had no wheel/tire incidents since.”

For most small to midsize operations, developing an in-house NDT capability is out of reach. The equipment is obtainable, but the expense of the training and required scope hours for the chosen technician trainee is not cost-effective. This means those managing such operations have to find someone who is qualified in NDT and has the tools to perform it. For example, there are companies that specialize in NDT for energy production; they may not be interested in performing a one-hour job on a wheel half. For aviation NDT, your best resource is a qualified FAR Part 145 Repair Station with NDT capability. The technicians there can perform the test and return the aircraft to service.

As more aircraft manufacturers rely on NDT for continued airworthiness of their products, the number of aviation NDT techs receiving more experience on different aircraft makes and models is growing. This expansion benefits the industry, obviously.

“The aviation NDT world is completely different from petroleum, nuclear power and rail inspection,” said Ray Vieselmeyer, the non-destructive testing team leader at Duncan Aviation, Lincoln, Nebraska. “Most of our technicians have a strong academic background coming from Southeast Community College in Milford, Nebraska, which has an excellent NDT training program.”

While technicians from other industries can be trained and capable to perform inspections on aircraft parts, using someone with experience on your specific aircraft model can be the better choice. It all boils down to a matter of trust, since that technician is responsible for the integrity of your aircraft and thus the safety of those on board.

Beyond that, the maintenance manager has to plan ahead and schedule NDT carefully because those services are in high demand. It may be worth adjusting your inspections early just to ensure that you are not left grounded while trying to get an appointment for an inspection. You also want to build up a level of confidence with several NDT providers in case you get hit with an AD or SB with a short compliance time. Good customers are usually bumped to the top of the list in a crisis.

Aviation maintenance has become much more reliant on NDT, and that demands specialized skill and experience of the technician. If you develop you own in-house capability, you’ll need specialized equipment and the designated technician must remain current and qualified, a considerable investment.

Most managers will likely choose outside support for their NDT needs. Those who follow that course must make sure the provider is qualified and experienced with the type of inspection needed for your aircraft. Whichever way you go, don’t hesitate undertaking required NDT inspections since they are uniquely capable of revealing real dangers hidden within.B&CA

by Mike Gamauf – Business & Commercial Aviation

Precision Acoustics Expands Needle Hydrophone Range

Ultrasonic equipment innovator and manufacturer, Precision Acoustics Ltd,
has expanded its pressure measurement range with new 2 mm and 4 mm
diameter needle hydrophones that have been designed to provide much
higher sensitivity at frequencies below 1 MHz.

Although primarily aimed at applications such as underwater acoustics and
characterisation of low frequency transducers, the new probes also suit
frequencies above 1 MHz where very weak signals need to be measured.
The frequency range is sufficiently broad that the new 4mm hydrophone has
been calibrated from 30 kHz to 40 MHz by NPL (London)

The new needle hydrophones are designed to be used with the HP
Submersible preamplifier that provides immediate signal buffering and acts
as a precision 50 Ohm source for Precision Acoustics’ high performance
hydrophone system. The larger active areas of these devices provides much
greater sensitivity (7V/MPa for the 4mm probe, 2.5 V/MPa for the 2mm
probe).

As a result these new devices have a lower noise equivalent pressure than
the existing range of plug-in interchangeable probes that have diameters
from 40 microns to 1 mm. These hydrophones can also be used conjunction
with the A20 in-line attenuator to permit the measurement of higher
amplitude signal whilst minimising the risk of preamplifier overload.

Precision Acoustics also manufacture a wide range of membrane and fibre
optic hydrophones as well as ultrasonic transducers, scanning tanks and
other acoustic measurement products that are exported worldwide.

NDT.org

Researcher Uses Microwave to Test Concrete and Aluminum

An electrical engineer at Missouri University of Science and Technology is

using microwave energy to test concrete and rehabilitated aluminum, and in

the future her work could lead to safer bridges and aircraft parts.

Dr. Kristen Donnell, an assistant professor of electrical and computer

engineering at Missouri S&T, studies those materials using an active

microwave thermograph (AMT) that highlights flaws that could compromise

safety or effectiveness. It works by using microwave energy to heat a defined

section of material, which is looked at using infrared thermography imaging.

It’s a method of nondestructive testing (NDT) that is fairly undeveloped,

Donnell said, but it’s being pioneered at Missouri S&T.

“It’s another tool in the NDT toolbox,” she says.

Donnell, who earned her master of science and Ph.D. degrees in electrical

engineering from Missouri S&T in 2003 and 2010, respectively, began

working on AMT about two years ago. She uses a 1- to 20-gigahertz high-

frequency horn antenna to heat the objects, then view them with an infrared

sensor that sends data to a computer.

Because the heat burst lasts only a few seconds, Donnell’s method reduces

the risk of heat damage that can happen when using traditional flash heat

lamps, and AMT is able to focus the heat at a predetermined depth instead

of heating the whole object. For example, when using a flash heat lamp to

look at a problem in a wall, the whole wall would need to be heated; in

contrast, the AMT method focuses heat on only a small section. It’s not

exactly an X-ray, “but it does allow us to look inside the interior of a structure

to show defects or problems,” Donnell says.

Using AMT in the lab, Donnell can set the system to focus on the middle of a

4-inch section of concrete. When the images are produced on a computer,

they can show if the rebar is compromised (rusted, corroded, broken) or still

in good working order. She also can look at the concrete for cracks or other

defects that could weaken it.

Donnell also can use AMT to look at materials that are wrapped in carbon

fiber. The AMT can check the carbon fiber’s adhesion for areas that aren’t

properly bonded. And Donnell can use the method to look at rehabilitated

aluminum for weak spots.

The possible uses for AMT testing are many, Donnell says, from checking

concrete bridges to aluminum used on aircraft. And it might some day be

possible, she says, to use this method to detect cancer. But all of that is in

the future.

“It’s probably a good 10 years away from use as an industry method for

testing,” she says.

Donnell is a research team member at the Applied Microwave Nondestructive

Testing Laboratory (amntl) and a senior member of the Institute of Electrical

and Electronics Engineers (IEEE). She is also an at-large administrative

committee member of the IEEE Instrumentation and Measurement Society,

and she is the distinguished lecturer program chair. Before starting her Ph.D.

program, Donnell worked in systems and electrical engineering for Raytheon. 

Image: Professor Kristen Donnell, right, points to results of an active

microwave thermography test that she and electrical engineering Ph.D.

student Ali Foudazi run. Their work points out flaws within concrete or

rehabilitated aluminum and could lead to increased safety for motorists and

airline passengers.

All Contents Copyright (c) 2015 NDT.org

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Non-Destructive Testing Equipment Market is expected to reach USD 4.78 Billion in 2021:Transparency Market Research

According to a new market report published by Transparency Market Research “Non-Destructive Testing Equipment Market – Global Industry Analysis, Size, Share, Growth, Trends and Forecast 2015 – 2021,” global non-destructive testing equipment market was valued at USD 3.21 Billion in 2014; growing at a CAGR of 5.8% from 2015 to 2021 to account for USD 4.78 Billion in 2021.

Nondestructive testing are exercised for determining the physical properties of materials such as ductility, ultimate tensile strength and fracture toughness. The non-destructive testing is used to ensure product reliability and integrity to control manufacturing processes. In addition, stringent government safety regulations for quality control, ensure safety and reliable performance of the machines, and increasing demand to improve quality and longevity of the machines are the major factors that are driving the non-destructive testing equipment market globally. However, lack of skilled technicians is posing a challenge to the growth of non-destructive testing equipment market.

The global non-destructive testing equipment market is segmented on the basis of technology, into ultrasonic testing,radiography testing, electromagnetic testing (form of Magnetic Particle Inspection (MPI)), visual testing and others (including magnetic particle testing and liquid penetrant testing). Ultrasonic testing led the global non-destructive testing equipment market in the year 2014. Key growth factors driving the ultrasonic testing market are its wide usage in steel and aluminum, construction, manufacturing, aerospace and defense and automotive sectors.

By end use industry market is divided into following segments: power generation industry, oil & gas industry, aerospace and defense industry, automotive industry and others (including plastic and polymer, and medical). As of 2014, power generation sector was the largest contributor in the global non-destructive testing equipment market. The main factors driving this growth of the power generation industry are increasing number of nuclear power plants and the subsequent increasing demand for machines used in power generation plants.

By geography, as of 2014, North America dominated the global non-destructive testing equipment market, accounting for 35.77% of the overall market. Huge investments in energy verticals such as oil and gas are majorly driving the market growth in North America. At the same time, Europe held the second largest market share and the demand for non-destructive testing equipment market is expected to increase during the forecast period. The market for non-destructive testing equipment in Europe is primarily driven by increase in demand for modernization of oil & gas and power generation sectors. The automotive industry is likely to contribute a large share to market revenues in Europe. Asia Pacific is expected to be the fastest growing region through the forecast period.

Report provides company market share analysis of various industry participants. The key players were also profiled on the basis of company details, product type, financial overview, historical roadmap, business strategies and the recent developments in the field of non-destructive testing equipment market.

Global non-destructive testing equipment market: by Technology

• Ultrasonic Testing (UT)
• Radiography Testing (RT)
• Electromagnetic Testing (ET)
• Visual Testing (VT)
• Other

Global non-destructive testing equipment market: by End Use Industry

• Power Generation
• Oil & Gas
• Aerospace and Defense
• Automotive
• Others

Global non-destructive testing equipment market: by Geography

• North America
  • U.S.
  • Rest of North America
• Europe
  • United Kingdom
  • Germany
  • France
  • Italy
  • Rest of Europe
• Asia Pacific
  • China
  • Japan
  • India
  • Rest of Asia Pacific
• Rest of the World (ROW)
  • South America
  • Middle East
  • Africa

Originaly posted in Industry Today

Metallic Gels Produce Tunable Light Emission

Source: ASM International

Researchers at Massachusetts Institute Technology, Cambridge, developed a family of materials that can emit light of precisely controlled colors—even pure white light—and whose output can be tuned to respond to a wide variety of external conditions. The materials could find a variety of uses in detecting chemical and biological compounds, or mechanical, and thermal conditions.

The material, a metallic polymer gel made using rare-earth elements, is a light-emitting lanthanide metallogel that can be chemically tuned to emit light in response to chemical, mechanical, or thermal stimuli—potentially providing a visible output to indicate the presence of a particular substance or condition.

The new material is an example of work with biologically inspired materials, explains assistant professor of materials science and engineering Niels Holten-Andersen. “My niche is biomimetics—using nature’s tricks to design bio-inspired polymers,” he says. There are an amazing variety of “really funky” organisms in the oceans, he says, adding: “We’ve barely scratched the surface of trying to understand how they’re put together, from a chemical and mechanical standpoint.”

Studying such natural materials, evolved over millions of years to adapt to challenging environmental conditions, “allows us as engineers to derive design principles” that can be applied to other kinds of materials, he adds. Holten-Andersen’s own research has examined a particular kind of crosslinking in the threads mussels use to anchor themselves to rocks, called metal-coordination bonds. These bonds also play an important role in many biological functions, such as binding oxygen to hemoglobin in red blood cells.

He emphasizes that the idea is not to copy nature, but to understand and apply some of the underlying principles of natural materials; in some cases, these principles can be applied in materials that are simpler in structure and easier to produce than their natural counterparts.

In this case, the use of a metal from the lanthanide group, also known as rare-earth elements, combined with a widely used polymer called polyethylene glycol, or PEG, results in a material that produces tunable, multicolored light emissions. The light emission can then reflect very subtle changes in the environment, providing a color-coded output that reveals details of those conditions.

“It’s super-sensitive to external parameters,” Holten-Andersen says. “Whatever you do will change the bond dynamics, which will change the color.” So, for example, the materials could be engineered to detect specific pollutants, toxins, or pathogens, with the results instantly visible just through color emission.

The materials can also detect mechanical changes, and could be used to detect stresses in mechanical systems, Holten-Andersen says. For example, it’s difficult to measure forces in fluids, he says, but this approach could provide a sensitive means of doing so. The material can be made in a gel, a thin film, or a coating that could be applied to structures, potentially indicating the development of a failure before it happens.

Metal-coordination bonds in polymers have been the subject of other work by Holten-Andersen: In a separate paper he published Aug. 31 in the journal Nature Materials, he reported making polymers with tunable mechanical properties, including stiffness. These materials are naturally self-assembling and self-healing, he says, and could be useful as energy-absorbing materials or in biological implants that need to be able to absorb impacts without breaking, he says.

This work was supported by the MIT Energy Initiative and the MIT Sea Grant via the Doherty Professorship in Ocean Utilization.

Image caption — Luminescent materials produced by the MIT team are shown under ultraviolet light, emitting different colors of light that can be modified by their environmental conditions. These light-emitting beads were made by materials science and engineering students Caroline Liu and Rebecca Gallivan. Courtesy of Tara Fadenrecht.

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Stinger The Swimming Robot Keeps Nuclear Reactors Healthy

Nothing says summertime in Georgia like a dip in the old swimming hole. But
near the town of Baxley, there’s one pool that’s not open to the public: the
crystal-clear blue waters of the containment vessel bathing the Edwin Irby
Hatch Power Plant’s nuclear reactor.

Although this is no place for a swim, the vessel must be monitored. In the
past, during scheduled maintenance and refueling downtimes, multiple
inspectors would clamber onto platforms that extended above the pool and
plunge into the vessel cameras mounted on poles or tied to ropes. Using
such handheld devices allowed them to get a close-up view of the welds in
the reactor pressure vessel and also surfaces that had to be kept in perfect
order. It worked, but it was a slow process and the inspectors had to protect
themselves from radiation from the fuel below.

But now the team has a new member that’s happy to jump in. He’s called
Stinger, the swimming robot, and allows nuclear plant personnel to go places
no human could reach before.

Stinger, which is a bit taller than an average human, is a steerable unmanned
underwater vehicle. He comes equipped with multidirectional, computer-
controlled thrusters and a high-resolution color video camera. “Where
Stinger’s camera and tools need to operate, a human could not survive in
that location,” says Brandon Smith, the GE Hitachi Nuclear Energy
mechanical engineer who led development of the machine. “That’s exactly
why we need robotics to do this kind of work. There’s just no other way to do
it and Stinger is built specifically to operate in that type of environment.”

The first-of-its-kind remote-operated vehicle is now being deployed to
nuclear power plants across the U.S. as they go through scheduled refueling
and inspection outages. It dives in the reactor pool for up to three weeks,
using cameras to get a good look at material degradation. In addition to its
camera technology, it also carries a high-pressure water nozzle, or
hydrolaser, to clean metallic surfaces to ensure a good, clean look at the
welds.

Smith and his team gave the robot a tungsten frock for protection and
electronics that are less susceptible to high radiation levels. A single
technician can operate it remotely from a tent hundreds of feet away from
the vessel. The robot is connected through a power and control umbilical to
the on-site operator and off-site, certified inspectors.

“The technician uses Stinger’s cameras to look for signs of degradation,”
says Smith. “It’s really good at getting into constricted spaces and around
tight corners to look for any sign that a component might fail—to catch
something before it becomes a problem.”

Stinger is now successfully performing inspections throughout the U.S.
nuclear industry. Smith says customers like it because it can work longer
with fewer concerns about radiation exposure. It can also perform its job
while other outage operations are going on since it doesn’t need inspectors
to be suspended above the reactor pool. These benefits translate to shorter
plant downtime and lower safety risks to employees.

“Our customers make money when their plants are producing power, so
they’re always trying to reduce the length of necessary downtime,” says
Smith. “They’re also always looking to reduce radiation exposure to workers.
By moving Stinger in and workers away to a lower dose area, they are able
to accomplish both goals.”

NDT.org
Image credits: GE Hitachi Nuclear Energy