RFID Modernizes Management of Nuclear Materials

April 3, 2009 By: Cyrena Respini-Irwin

Radio-frequency identification technology enables personnel to monitor radioactive and fissile packages from a safe distance.

Unobtrusive and economical, radio-frequency identification (RFID) technology has made its way into our daily lives: even the library book on your desk or the dog asleep at your feet may bear a microchip that uniquely identifies it. And as RFID tags become ever cheaper, they're being used for a multitude of supply chain and asset management tasks, tracking product shipments and expensive equipment. But when it comes to "assets" that are actually dangerous liabilities — like drums full of nuclear materials and waste — the need for reliable monitoring gains new gravity.

In the past few years, researchers at Argonne National Laboratory (ANL) led by Yung Liu, senior nuclear engineer and RFID project manager, have made huge strides in this area. The scientists have developed an RFID system that collects detailed data about containers of nuclear materials, providing real-time updates on environmental conditions and the containers' integrity.

The core of the system is an RFID tag — which transmits information in reponse to an interrogator, or RFID reader — joined with a variety of sensors and encased in a protective plastic housing. Temperature, humidity, vibration, and other sensors collect data about how containers are faring during storage and transportation, and can trigger alerts if their thresholds are exceeded. "The great value of our system is the information that comes from the suite of sensors; RFID is just the carrier of the message," Liu explained.

The addition of GPS units, either mounted in a transport vehicle or coupled with the RFID tag, provides precise location information. RFID readers, which can be mounted in a truck or storage facility, send the tags' data via a secured network to a central Web server at ANL. The application software can then use e-mail or text messages to automatically alert critical personnel, or emergency responders in the surrounding area, of any problem.

Nuclear engineer Yung Liu examines data on his laptop from the RFID device developed at Argonne National Laboratory. The technology allows users not only to track nuclear materials, but also to remotely monitor environmental and physical conditions such as temperature and humidity. Photo courtesy of Argonne National Laboratory.

Designing for a Demanding Application

Liu's team began developing the system in 2006, and immediately faced challenges stemming from the unusual nature of their task. For example, Liu explained, the 433-megahertz RFID tag they purchased from Savi Technology required relatively little power, and provided good communication near metal — but it wasn't designed to withstand radiation, so it had to be tested and modified before use.

Battery life was another concern; the more frequently they have to be changed, the more often a worker must risk exposure to radiation. The answer was to employ a battery control board that draws power from one of four lithium cells, switching to a fresh battery whenever one becomes drained. This way, the system can run for 10 years or more without human intervention.

Finally, addressing safety and security was paramount. A force-sensitive sensor monitors the compression of the drum's seal, and records any loosening of the bolts that secure the lid. The contents of each container are recorded in its tag, but the information is encrypted to prevent unauthorized parties from reading it. In addition, system users can put the tags into "deep sleep" mode so they won't transmit any information, even though the sensors continue to operate.

Taking To the Road

Once these issues were resolved, the system's viability was tested during a demonstration conducted in April 2008 (watch a video here). Except for the use of empty storage containers, "it was about as realistic as you can get," said Liu. The drums were transported some 1,700 miles, from ANL to Aiken, South Carolina; Knoxville, Tennessee; and back to Chicago, Illinois.

Staged incidents showcased the system's emergency alert capabilities. When a bolt was loosened while the transport vehicle rested at a truck stop, an automatic alarm message was broadcasted to the observers participating in the demo. The participants could then log into a secure Web site and examine the current status, as well as the event history, of all the drums on the truck.

A World of Uses

Liu hopes to see this system implemented on all nuclear-materials packages someday. "There are many benefits if we can deploy such a system on a large scale," he observed. That's a tall order; the Department of Energy's Office of Environmental Management, which funded this project, has the unenviable mission of "risk reduction and cleanup of the environmental legacy of the nation's nuclear weapons program, one of the largest, most diverse, and technically complex environmental programs in the world."

Already, Liu's team has developed a temperature-monitoring system for the Domestic Nuclear Detection Office. Currently, they're working on projects such as transporting plutonium across the country and storing nuclear materials containers in South Carolina and New Mexico. Of course, nuclear concerns aren't limited to the United States; the International Atomic Energy Agency is also interested in their work, Liu reported.

"We also see applications outside the nuclear area," said Liu, explaining that the system could be used for containers of hazardous chemicals, or any high-value materials. "We started from the device level, and took it all the way up to a complete system . . . that can work for a few containers or for thousands."

Bookmark it: digg del.icio.us technorati yahoo facebook twitter

Add Comment