Radioactive Scrap Threat Heats Up

“Hot” sources in scrap can result in devastating health and financial consequences for scrap dealers and processors. Fortunately, manufacturers offer an array of etection options that can significantl

Subscribe
August 7, 2001

Three strikes and you’re out! For a baseball player, it’s an unwanted trip to the dugout with the hope that the next time up at the plate things will turn out differently. But for a scrap processor who’s had his third load rejected by a steel mill because it set off a radiation detector’s alarm, it could mean the end of a business relationship.

Recent events have necessitated the steel mills’ tough stance. From 1983 through 1997, there were 49 confirmed meltings of radioactive sources worldwide, with the vast majority occurring in the U.S., according to a paper by Joel E. Lubenau and James G. Yusko in the March 1998 issue of Health Physics.

Andrew G. Sharkey, III, president and CEO of the American Iron and Steel Institute (AISI) in testimony before the Nuclear Regulatory Commission (NRC), testified that from 1983 through June 1996 there were almost 1,900 discoveries of radioactivity in scrap. Sharkey noted that at steel mini-mills the cost of decontamination, disposal and shutdown losses reached $23 million in a single incident and average in the range of $8 to $10 million. Sharkey testified that the cost of a radioactive melt at a large integrated steel mill is estimated to run as high as $100 million or more.

PROBLEM TO GROW?

The problem of radioactivity in scrap is expected to grow, according to Mike Mattia, Director of Risk Management, Institute of Scrap Recycling Industries Inc. (ISRI), Washington, D.C.

"There are tens of thousands of radioactive sources out there that have the potential to find their way into the scrap recycling stream," says Mattia.

Compounding the problem is the increasing amount of scrap being imported from countries whose controls are not as stringent as are those in this country, points out James K. Hesch, product manager for vehicle monitoring systems, Eberline Instruments, Santa Fe, N.M.

"Stolen sources are becoming a problem as well," says Hesch. He tells of two cobalt-60 cameras and an iridium-192 camera that were stolen in the Houston area and sold as scrap metal. The incidents resulted in 19 people on-site at the scrap yards and seven others being exposed to radiation.

Health risks are not confined to scrap yard workers. For example, in Mexico, notes Hesch, a source containing cobalt was transferred from a scrap yard and was smelted. This contaminated the steel mills and the products they produced. Radioactive rebar was built into patio furniture that was shipped to the United States and distributed in 40 states. Rebar was also imbedded at construction sites. All the material was eventually returned to Mexico for disposal except for a small amount imbedded at the construction sites. It was determined that the rebar at these sites, which was encased in concrete, did not pose a health or safety risk.

But Hesch emphasizes that the Mexican incident highlights that there is a "tremendous potential for risk" with radioactive scrap.

SOURCES OF RADIOACTIVE SCRAP

If it’s a given that radioactive scrap is becoming more pervasive, then what are the sources of the problem? There are several sources of radiation, all of which can find there way into a scrap yard, says Richard Smola, design engineer, Ludlum Measurements, Sweetwater, Texas. The first type is known as NORM – naturally-occurring radioactive material. This type of material is often found in steel pipes used in oil and drilling operations. Scale, which contains trace amounts of radium, builds up in the pipes, typically around joints and collars. When the metal is discarded it can find its way into a scrap yard, notes Smola.

The second source is from medical institutions such as hospitals. Machines used in radiotherapy for cancer and other diseases are typically involved. ISRI’s Mattia notes, however, that hospitals are well regulated. This cuts down significantly on the possibility that radioactive sources from these machines will enter the scrap stream.

Smola adds that hospitals typically use radioactive sources with short-lived isotopes. "These decay out in a couple of days and typically are not a problem," he says.

Man-made devices, however, are a significant radioactive source. These include industrial gauges and gauges such as those used in aircraft cockpits. Frequently, the gauges are painted over or are mistaken for a harmless motor, says Gary G. Wascovich, senior sales supervisor, Bicron NE, Solon, Ohio. Or, the gauges are attached to the pipes. When a plant is dismantled these gauges find their way into the scrap stream.

Gauges are at times not properly labeled, says Smola. Or, he adds, the labels have been removed, painted over, or covered with dirt, making detection difficult.

Another potential source of radioactivity is from "activated scrap," says Smola. In this situation, metal at a nuclear facility becomes radioactive, or activated, by virtue of being in close contact with radioactive sources. If the facility is dismantled, there is the possibility that activated metal will likewise be put into the scrap stream.

WHO’S AT RISK?

With so many potential radioactive sources "in play" who is at risk?

"Everyone in the scrap industry is vulnerable," says ISRI’s Mattia.

Ray Turner, quality engineer The David J. Joseph Company, Cincinnati, seconds this view. Although the large processors have a higher probability of receiving NORM, the "mom and pop" operations are vulnerable too, says Turner.

The risk also cuts across types of scrap processors. Yusko, radiation protection program manager, Pennsylvania Department of Environmental Protection, Pittsburgh, notes that in addition to detections among ferrous processors, there have been detections on the aluminum and copper recycling side.

Processors who shred or shear material have a greater risk than those who just peddle scrap, according to Ludlum’s Smola. He points out that a shredder or shear can compromise a radioactive source’s protective lead or steel housing. When this occurs the radiation can not only contaminate both the machinery and scrap, but can cause medical problems for workers at the scrap facility.

REGULATORY BLUES

With the potential for health and safety problems with radioactive scrap, it would seem logical that someone or some agency is minding the store. But the experts Recycling Today spoke to emphasize this is not always the case.

Ludlum’s Smola points out that there is a petition before the Nuclear Regulatory Commission to adopt more stringent regulations regarding radioactive sources in the recycling and waste streams. Many facilities operating under what is known as a "general license" may not even realize they have radioactive sources. Further, many of the radioactive gauges fall under general license requirements, which are less stringent than those issued under a specific license.

AISI’s Sharkey testified that his organization, whose 49 member companies account for approximately 70% of the raw steel production in the U.S., supports the NRC-Agreement State Working Group recommendations that call for:

* Enhanced regulatory oversight of general and specific licensees possessing devices exceeding designated activity thresholds;

* Increased responsibilities and obligations for licensees and device vendors;

* Significant penalties for lost devices; and

A program for the handling and disposing of "orphaned" devices.

Turner points out that so-called "agreement states" have entered into a contract with the NRC to regulate devices according to federal guidelines. Unfortunately, only about one-half of the states are agreement states.

Smola also notes that whereas the NRC has granted licenses for radioactive gauges and such, there still are no reporting requirements to speak of. This makes tracing of these devices extremely difficult.

Yusko says that recommendations are before the NRC commissioners regarding how to better control radioactive sources. And, David J. Joseph’s Turner points out that states continue to regulate NORM. But the degree of regulation varies from state to state.

TAKING CHARGE

With the ever-present potential for contamination and an unsettled regulatory environment, it is incumbent on scrap dealers and processors – no matter what their size – to take charge of the situation. This means installing radiation detection systems.

Not to install a system could be a form of economic suicide. Steel mills and other consumers have installed extremely sophisticated radiation detection systems. As mentioned above, some steel mills are now using a three strikes and you’re out rule.

"Some mills will take care of a problem and charge the scrap processor," says John R. Bublitz, vice president of sales, Exploranium Radiation Detection Systems, Knoxville, Tenn. But then again, other mills are returning loads that trigger an alarm, without checking for the source – even though the problem may only be a relatively harmless NORM source. This can be extremely costly to scrap processors.

TYPES OF DETECTORS

So what type of radiation detector should a scrap processor "arm" itself with? Basically, there are three types of radiation detectors available. These include (1) hand-held; (2) small area stationary, and; (3) large area stationary. Let’s take a look at each in turn.

"Hand-held detectors are for close proximity monitoring and are not intended for checking truck loads, says Eberline’s Hesch. These units have a sodium iodide sensor. A small-size scrap dealer should have this type of detector as a minimum to check scrap for a radioactive source. Depending upon the manufacturer, hand-held units cost from $400 to $1,500.

Hesch adds that for mid- to large-size scrap dealers and processors, a hand-held unit can be used to "go over" a load when a larger fixed system sets off an alarm. Bublitz says that a hand-held unit should not be used to "walk down" the side of a truck looking for a source. It simply will not do the job.

Mark McCarthy, marketing manager, National Nuclear Corp., Sunnyvale, Calif., notes that a source may be "buried" in tons of scrap. A hand-held detector would not have the sensitivity to detect the source.

Small area stationary units, such as Bicron’s ASM-6, use a sodium iodide detector system. They can be mounted on poles. According to Bicron, these detectors are used to monitor small vehicles, Gaylord boxes and platform scales. Systems such as the ASM-6 are not recommended for rail, truck and barge monitoring, points out Joseph G. Bellian, sales manager, Bicron.

Yusko agrees. "If you’re processing a truck every five minutes, a monitor on a pole is not going to do," he says.

Small stationary systems are in the $5,000 to $6,000 range.

The "heavy lifting" in radiation detection falls to the large area stationary monitors. These are made by several manufacturers and cost from $15,000 to $100,000 and up. These systems use a plastic scintillator as their detector. The larger the area of the detectors, the greater the sensitivity and cost. These systems are the ones used to monitor scrap coming in via rail, truck and barge. Typically, they consist of two or three monitors that flank the truck or rail car. (Barge monitors, such as RAD COMM Systems’ RC/5 Barge System, move over the top of the scrap.) Microprocessors analyze data sent to them from the detectors. When counts above background radiation are detected an alarm goes off. Some systems are monitored through a modem-based teleservicing system to ensure they are operating properly. The biggest systems are needed for monitoring rail cars owing to the thickness of the cars and the amount of scrap they contain.

A radiation detection system can pay for itself very quickly if it detects a source, says Smola. The alternative, he adds, could easily be the contamination and shutdown of a scrap yard. In essence, the scrap yard operator is "buying himself an insurance policy with a radiation detection system."

REDUNDANCY RECOMMENDED

In a perfect world, all sources would be detected on the first pass through a radiation detection system. Although there are systems on the market with a reported 99% detection probability, Smola notes that "there is no system that is perfect." Factors that can affect a system’s sensitivity include distance between system and the source, how long the source is before the detector’s sensitive zone, the amount of shielding around the source, NORM in dirt and background radiation levels.

Even the weather can trigger false positives. ISRI’s Mattia notes that during rain storms background radiation can double.

Radioactive sources on barges are particularly problematic, according to Bruce D. Bateman, vice president sales and marketing, RAD COMM Systems, Brampton, Ontario. The massive amounts of material, he notes, could easily hide a source.

For this reason, many equipment makers recommend detectors be placed at different points in the scrap stream.

"One of the greatest risks is when a shielded source goes through the shredder," says Hesch. "It goes from being a low risk to being a high risk."

One way for scrap yard operators to minimize the risk of shredding a source is to put a small stationary system at points before and after material is shredded. Scrap processors who are upgrading from a small to the large stationary systems should consider putting the smaller system on-line to monitor their shredder operations, says Hesch.

WORKER TRAINING

Scrap yard personnel are a crucial factor in detecting radioactive sources, according to Bateman. "You have to educate people as to what a shielded source looks like," he says. This includes identifying sources shielded by lead and steel.

Proper use of equipment can mean the difference between a successful detection and letting a source slip into the scrap stream. "More training leads to fewer contamination mishaps," says Smola.

IF IT’S HOT

What should a scrap processor do if an alarm goes off?

Mattia recommends running the load through a second time, and perhaps even a third time. Some systems will pinpoint the general location of a suspected source in a load.

Most experts advise using a hand-held unit to isolate the source. The source, when located, can then be put off to the side and the load can then be sent on its way.

Yusko advises that scrap processors "call in the authorities, generally state radiation control people," to deal with the source. Unfortunately, scrap processors must contend with a hodgepodge of federal and state regulations as well as interagency rivalries.

Mattia points out that ISRI is working on the problem of what scrap processors should do with hot sources. An ISRI conference will be held in late June in Orlando on radiation detection and the problem of radioactive scrap.

For now the most prudent course for any scrap dealer or processor is to buy and install the radiation detection system that’s appropriate for its needs. After all, thousands of dollars of protection up front is far preferable to several million dollars worth of cure on the back end.

The author is editor of Recycling Today.

 

Sidebar

A HIGH PRICE TO PAY

It might be difficult to argue that radioactive scrap is a major problem based on the number of incidents alone.

"There are seven to ten incidents per year nationwide," estimates James Cowan, general manager of the North Star Steel mini-mill in Kingman, Ariz., referring to incidents where mills actually melt radioactive scrap.

But while that number may seem insignificant, the consequence of any given incident is what has grabbed the attention of the steel and scrap industries. "It’s very detrimental when you melt radioactive scrap," says Cowan, who also notes that cleanup costs can reach the $10 million mark.

John Correnti, president and CEO of Nucor Corp., Charlotte, N.C., used a recent speaking opportunity at the ISRI Annual Convention to plead for help from the scrap industry in ferreting out radioactive scrap. "It’s big bucks to a steel mill for cleanup, not to mention the lost production," Correnti noted.

"All of our mills have five to ten radioactivity detection devices," the steel executive said of his own company’s line of defense.

—Brian Taylor