Identifying Radioactive Sources

Teaching your employees to look for certain shapes, colors, symbols, letters, and terms can help keep radioactive material out of your scrap shipments.

 The problem is plain to see—and so may be part of the solution.
 The problem is that there’s a lot of radioactive material that either has entered the scrap stream or potentially could get mixed in with otherwise usable scrap metal. In the past 20 years, there have been roughly 4,000 occurrences in the United States in which radioactive material ended up somewhere other than where it was supposed to be, notes Mike Mattia, ISRI’s director of risk management. And those are just the reported occurrences. The total amount of misplaced radioactive material could be as much as 10 times more (though it should be noted that 70 percent of the 4,000 occurrences involved naturally occurring radioactive material as opposed to licensed radioactive sources).

   This is especially troubling for scrap processors because too often that missing radioactive material ends up in the recycling stream.
   Much of this material comes from so-called generally licensed radioactive devices, which refers to equipment that contains small amounts of a shielded radioactive source—equipment such as smoke detectors, medical monitors, and industrial gauges that, for instance, test moisture levels in the ground or count items moving along a conveyor belt. Even some of the equipment that scrap processors themselves use, such as X-ray fluorescence metal analyzers, contain generally licensed material. The radioactive material in these general sources is, overall, less dangerous than bomb-grade material such as plutonium, which is a specifically licensed source and much more strictly regulated.
   Still, if a generally licensed source is broken open at the scrap plant or melted in a furnace, the exposure could injure or kill workers and lead to millions of dollars in environmental cleanup costs.
   While users of generally licensed sources are supposed to keep track of their radioactive devices—they can be fined, in fact, if they lose them—the reality is that the regulations depend on the good faith of the user. As Mattia explains, missing sources are supposed to be reported to state and federal regulators, but many times the original user goes out of business, or the company changes hands, or the device gets stolen, or the current users forget that years and years ago someone installed a piece of machinery with a radioactive source in it. When that piece of machinery is scrapped or when the factory or office is demolished, nobody knows that there’s a radioactive source buried inside the piles of scrap metal.
   It’s that metal, of course, that puts scrap recycling facilities at such risk.“The one thing that all generally licensed sources have in common is metal,” Mattia says. “The radioactive material is in a metal shell. The metal shell is in a metal housing. The metal housing is in a metal gauge. The metal gauge is in a metal machine or metal ductwork or piping.”
   As a result, long after the machine or ductwork or piping has lost its initial value, the metal itself remains valuable as scrap. So someone sells it to a scrap processor, who then shears it, shreds it, bales it—and if all that doesn’t breach the housing around the general source, the material then goes to a mill for melting and the radioactive source gets exposed.

Beyond Detectors
Radiation detectors are useful in finding such general sources before they enter your scrap stream. “You’re playing Russian roulette if you don’t have one,” Mattia warns, though he adds that many detectors aren’t properly installed or used. The detector, for instance, might be too far away from the incoming scrap, or trucks might move past the sensors too quickly for a good reading, or the rest of the scrap in the load might shield the source enough to prevent its detection, or any number of other little problems could crop up to prevent the detector from alerting you to the source.
   At best, correctly installed and used detectors might catch 95 percent of your potential radiation problems, Mattia believes. That’s respectable, he adds, except when that other 5 percent of problems “will kill you or shut you down.”
   So as an added protection, Mattia recommends training your employees to visually recognize signs of potential radioactive sources—much like scrap workers were taught years ago to recognize PCB capacitors—so that when they’re buying material, dismantling a structure, or watching the scrap come across a scale, they’ll see something that makes them pause and think, “This might be radioactive. Let’s look at it more closely.”
   Mattia, who teaches an ReMA course on the subject, explains that visual identification of radioactive scrap is based on the fact that certain words, symbols, colors, letter-and-number combinations, and shapes are all associated closely with radioactive material. Workers can learn to look for these elements and be on guard when they see them.

Words of Warning
A good place to start, for instance, is with the international symbol for radiation. The three-bladed trifoil is usually depicted in either black or magenta and set against a yellow background, Mattia says. It might appear on a label or plate attached to the device. In certain cases, it could be etched into the surface of the device, especially smaller devices.
   Certain words also provide strong clues that you’re dealing with radioactive scrap. Some, like “Caution” and “Danger,” are obvious warnings, while others—such as “isotope,” “roentgens,” “curie,” and “becquerel”—are dead giveaways once you learn to recognize them, Mattia notes. Workers should also be trained to watch for the abbreviations of these words, such as R and Rem for roentgens, Ci for curie, and Bq for becquerel, especially if they’re combined with a number.
   Other letter-and-number combinations are equally strong indicators of radioactive material. The letter C, for instance, when combined with either a number in the upper left-hand corner or to the right—such as 14C or C-14—designates a carbon isotope. Likewise, 241Am refers to Americium-241, an isotope commonly found in certain metal-analyzing equipment.
More keywords or terms to know include “disintegrations” and “counts,” especially when used in phrases such as “disintegrations per minute” or “counts per second.” Like other terms, these might be abbreviated—for instance, as “dpm” or “cps”—so it’s important to recognize both uses.
   Workers should also be suspicious whenever they see words such as “rays” and “particles” as well as “alpha,” “beta,” and “gamma,” along with the Greek letters associated with them—a, b, and g, respectively. These words might appear as part of a warning label, or they might just appear in the name of the device’s manufacturer, Mattia notes. So watch out for products from companies with names like Gamma Industries or K-Ray or AccuRay, he suggests. Similarly, if workers see words like “scan” or “measure” on a device—such as “measurex” or “inscan”—they should treat the scrap as potentially radioactive until proven otherwise.
Sometimes, a company’s name can set off figurative alarm bells even when it doesn’t include any of the key radiation-related words mentioned above. That’s because the company itself has a long and well-known association with manufacturing radioactive devices. So always check out a piece of equipment that comes from, say Siemens or Troxler, Mattia says. What you find might not turn out to be one of the company’s radioactive products, but it’s better to err on the side of safety.
   The letter combination “ium” should also put workers on their guard, given how many radioactive elements end with that suffix. For instance, there’s radium, uranium, strontium, and thorium, to name a few. Of course, plenty of radioactive elements do not end in “–ium,” and some words that do include the suffix aren’t radioactive at all—but again, it’s safer to assume something is radioactive when it isn’t than vice versa.
   With any of these warning signs for radioactivity, workers must be taught more than just how to recognize the intact words, signs, colors, letters, and numbers. They also need to look for even the slightest shred of evidence that one of those warning signs is present. After all, Mattia explains, the device that ends up in your scrap pile may have spent 20 years or longer in an industrial setting. It might be rusted, scratched, painted, or otherwise altered. You probably won’t get a nice, intact sign that announces “CAUTION: RADIATION,” with a clearly printed trifoil.
   Instead, all you might see is a bit of yellow under the corrosion, or part of a word like “CAUTION,” or some of a letter-number combination. You might notice that something was etched into a device’s surface, though it’s no longer legible. Or you might see a piece of what could have been a plate attached to the device. Such clues could suggest that the product contains radioactive material.

Origins and Appearances
Devices that come from certain industries or operations or that have certain features or shapes can also alert you to potential radioactive problems. If you’re going to take scrap from an old medical facility, for instance, you might end up with a radiographic camera or other nuclear medicine device. Or if you plan to scrap a canning or bottling operation, watch out for radiographic measuring equipment that might have counted items or checked fill levels on a conveyor belt. In fact, Mattia notes, any time you see a device that surrounds or stands over a moving belt, there’s the possibility it contains radioactive material.
   Of course, if you don’t dismantle the facility, you won’t necessarily know where the device came from or how it was used there. Fortunately, there are other clues. Radiographic cameras usually have a key to turn the shutter—it’s a safety device designed to prevent accidental exposures, but also a good warning sign that radioactive material might be present. Likewise, a device with an A-frame setup or a C-shaped piece of equipment (often a square-shaped C) can tip you off that the instrument was used to monitor something on a conveyor, either from above or from the side.
Also, if it’s clear that the device somehow wrapped around a pipe or ductwork, that’s another potential sign that it was a radioactive measuring instrument. Moreover, if one part of the device has a bulbous head, you should definitely treat it as potentially radioactive.

Levels of Danger
In addition to recognizing things that might be radioactive, it’s important to make sure that workers know something about the different levels of danger associated with different radioactive devices. After all, the device might arrive at the scrap facility with its shielding already breached or it might not be discovered until it’s been accidentally opened. So workers must understand the difference between, say, 50 microroentgens of exposure and 50 milliroentgens—because the difference can literally be life and death.
   “We often get calls from recyclers who’ve found a radioactive source and say, ‘Our meter is reading 50,’” Mattia says, “and we’ll ask them, ‘50 what?’ Often, they’re not sure. If it’s 50 microroentgens, it’s probably no big deal. But if it’s 50 milliroentgens—which is one thousand times more dangerous—then they’d better run.”
   So be sure your employees understand the differences between prefixes such as “milli-” and “micro-” and teach them to recognize the symbols associated with each (the letter “m” for micro and the Greek letter “u” for milli), Mattia explains. Also, be sure they’re well-trained on whatever radiation detectors you use. Often, these devices have different settings, based on multiples of 10, 100, or 1,000. You don’t want to be in a situation where you think you’re detecting a safer micro reading when in fact the device is warning of a milli exposure.
   A good detector should always be your first line of defense, Mattia stresses, but the eyes of a well-trained employee can easily be the critical last line of defense to keep a radioactive source from contaminating your equipment, endangering your work force, or reaching your customers. 

Training Options
Want more training on the visual identification of radioactive sources and other safety-related topics? You’re in luck because ReMA offers on-site and Internet-based training programs to meet your needs.
   On-Site Convenience: Mike Mattia, ISRI’s director of risk management, can provide personalized half-day or full-day training sessions at your facility on topics such as radioactive scrap, the psychology of safety, creating an effective safety program, how to be a safety trainer, and surviving an OSHA inspection. Sessions can also be customized on a topic of your choice.
   The Online Advantage: ReMA also offers Internet-based education and training that brings programs to you through your computer. For only $89 per computer connection, ISRI’s online training sessions are accessible anywhere you have access to the Web—for as many people as you can put in front of your computer. This service enables you to eliminate travel costs, reduce time away from your business, and receive training for a fraction of the cost of traditional workshops and seminars.
   Online-training topics include radioactive scrap, baler safety, surviving an OSHA inspection, storm water best management practices, and other environmental issues.
   ReMA will soon be offering a free demo of its online education and training service so you can see for yourself how easy it is to use.
For more information on ISRI’s on-site and online training programs, call Mike Mattia at 202/662-8515.•