"Supergel" system for cleaning radioactively contaminated structures nears deployment

The gel adheres to vertical surfaces and can be sprayed on using commercially available equipment. The consistency of the sprayed-on gel does not change significantly upon application. Here project leader Michael Kaminski of Argonne's Chemical Engineering Division sprays on the gel as members of the Argonne research team, equipment vendors, and agency representatives observe.

The gel was removed with a dry/wet vacuum with "squeegee" attachment, purchased at a home supply store. The vacuumed surface of the concrete remained wet but contained none of the gel material.

In late September Argonne National Laboratory's system to safely capture and dispose of radioactive elements in porous structures outdoors moved a step closer to deployment with the outdoor demonstration of the gel's application and cleanup, using commercially available equipment.

The system can decontaminate structures such as buildings and monuments using a spray-on, super-absorbent gel and engineered nanoparticles. Such a system would help the nation be more prepared in the event of a terrorist attack with a “dirty bomb” or other radioactive dispersal device.

The polymer gel that is used to absorb the radioactivity is similar to the absorbent material found in disposable diapers. When exposed to a wetting agent, the polymers form something like a structural scaffold that allows the gel to absorb an incredible amount of liquid.

The amount of contamination that can be removed depends on the characteristics of the contaminated structure — its age, type of material, whether painted or unpainted--and the radioactive isotope involved. Removal ranges from roughly 80% to nearly 100%.

According to project leader Mike Kaminski, "Our focus is on rapid response--getting as much of the contamination as we can, as quickly as we can, and filling a technology gap immediately."

Argonne's Technique Leaves Structures Intact

With current techniques it is common practice to demolish contaminated materials instead of attempting to remove radioactivity because no process currently exists that can effectively remove the contamination. Argonne's technique would allow surfaces to be preserved, which means that monuments or buildings would not have to be defaced to remove radiation.

Using a simple, three-step procedure, the system operates much like an automated car wash.

• Application
• Reaction
• Cleanup

Next Steps

The next step is to test the process in a hot cell facility using actual radioactive materials. Plans call for a pilot-scale demonstration followed by full deployment within the next 6 to 12 months.

A patent application has been filed and the Supergel technology is expected to be available for licensing.

The Supergel project is funded by the Department of Homeland Security through the Technical Support Working Group (TSWG) to help the nation be more prepared in the event of a terrorist attack with a "dirty bomb" or other radioactive dispersal device. TSWG is .the U.S. national forum that identifies, prioritizes, and coordinates interagency and international research and development (R&D) requirements for combating terrorism. The TSWG rapidly develops technologies and equipment to meet the high-priority needs of the combating terrorism community, and addresses joint international operational requirements through cooperative R&D with major allies.

For More Information

"Ghost Town Busters. After a dirty bomb attack, special formulations could counter radioactive contamination" (Science News Online, 168(18), 282, October 29, 2005)

Community College Student at Heart of "Supergel" Project

Contact Michael Kaminski (630-252-4777, kaminski@cmt.anl.gov).