Ill. (July 2, 2004) – Porous structures, such as brick
and concrete, are notoriously hard to clean when contaminated
with certain types of radioactive materials. Now,
thanks to researchers in Argonne 's Chemical Engineering
Division, a new technique is being developed that
can effectively decontaminate these structures in
the event of exposure to radioactive elements.
Researchers are using engineered nanoparticles and
a super-absorbent gel to design a clean-up system
for buildings and monuments exposed to radioactive
materials. Having this system available will allow
the nation to be more prepared in case of a terrorist
attack with a “dirty bomb” or other radioactive dispersal
“If a radioactive device were activated in public,
the primary concern would be widespread contamination,”
said Michael Kaminski, lead scientist of the project.
“This contamination is particularly hard to remove
in buildings made from brick or concrete, where the
pores, or holes, in those materials make it easy for
radioactive materials to become trapped.”
Enter Kaminski and his team of Argonne scientists,
whose decontamination system could safely capture
and dispose of radioactive elements in porous structures
in an outdoor environment. Using a simple, three-step
procedure, the system operates much like an automated
car wash, where remote spray washers apply a wetting
agent and a super-absorbent gel onto the contaminated
surface. The wetting agent causes the bound radioactivity
to resuspend in the pores. The super-absorbent polymer
gel then draws the radioactivity out of the pores,
and fixes it in the engineered nanoparticles that
sit in the gel. Finally, the gel is vacuumed and recycled,
leaving only a small amount of radioactive waste.
“The polymer gel we use to absorb the radioactivity
is similar to the absorbent material that's found
in disposable diapers,” Kaminski explained. “When
exposed to a wetting agent, the polymers start to
cross-link, forming something like a structural scaffold
that allows the gel to absorb an incredible amount
The Argonne technique would overcome many of the shortcomings
of current radioactive decontamination operations.
“Right now, it is common practice to demolish the
contaminated materials in hopes of getting rid of
the radioactivity. Our technique would allow surfaces
to be preserved, which means that we wouldn't have
to deface monuments or buildings just to remove the
radiation,” said Kaminski.
The group has 18 months to complete development of
the decontamination method. The project will culminate
in a prototype demonstration of the technology using
real contaminated concrete samples. This work is being
done as part of an interagency Technical Support Working
Group project selected from more than 3,000 submitted
in May 2003 and funded by the Department of Homeland
Kaminski's group is also developing other technologies
for biomedical and military applications, using magnetic
nanoparticles. Experience in that work, funded by
the U.S. Department of Energy, led to the super-absorbent
gel project and other work for defense and homeland
"Within our group, we are combining our experience
from the past several years in areas of nuclear power
plant decontamination, engineered nanoparticles and
polymer gels to develop this new decontamination technology,"
Kaminski says. "It has provided a potential solution
to one of the key challenges in counter-terrorism."
The nation’s first national laboratory, Argonne National
Laboratory conducts basic and applied scientific research
across a wide spectrum of disciplines, ranging from
high-energy physics to climatology and biotechnology.
Since 1990, Argonne has worked with more than 600
companies and numerous federal agencies and other
organizations to help advance America's scientific
leadership and prepare the nation for the future.
Argonne is operated by the University of Chicago for
the U.S. Department of Energy's Office of Science.
— Margret Chang
For more information, please contact Donna Jones Pelkie
(630/252-5501 or email@example.com) at Argonne.