Spurred by the 2011 emergency at the Fukushima Daiichi Nuclear Power Plant in Japan, nuclear engineers and researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory sought to answer the question: How can we improve the way first responders handle emergencies like Fukushima?
Standard responses to these emergencies are slow and expensive. To clean buildings, for example, skilled workers must shave concrete walls or apply expensive chemicals and gels that are tough to obtain quickly. Response teams sometimes even destroy affected buildings and materials to remove radiation.
“It has enormous potential because it cleans surfaces in minutes, not hours or days.”– Michael Kaminski, materials engineer in Argonne’s Nuclear Engineering division.
“Current approaches won’t work well if radioactivity is released in a city,” said Michael Kaminski, a materials engineer in Argonne’s Nuclear Engineering division. “If a radiological dispersal device — or ‘dirty bomb’ — goes off, first responders need to decontaminate the area and restore basic services rapidly in order to reduce radiation exposure.”
Kaminski has developed his own system of interchangeable equipment, tools and materials that decontaminates urban areas faster than other approaches.
In Kaminski’s process, responders first add a salt solution to water and spray brick and concrete areas with a firehose. The salt molecules repel radionuclides from surfaces, which emergency workers then trap in pop-up, plastic-lined channels. At that point, firefighters filter the contaminated runoff water in several contained pools before purifying and recycling it using a mobile filtration system.
The idea stems from Kaminski’s first decontamination breakthrough more than 10 years ago, when he developed a gel that extracts and traps radionuclides from building exteriors and monuments. “I got the idea when I was changing my sons’ diapers,” said Kaminski. “Disposable diapers are so absorbent — why couldn’t I use a similar material to clean hard surfaces after radioactivity is released?”
The resulting ‘supergel’ was a hit that has been licensed to Environmental Alternatives, Inc. for use in the nuclear energy industry. Yet the gel, like car wax, takes time and skill to apply and remove correctly.
To decontaminate areas more quickly, Kaminski developed the wash and recovery technique. “Flexibility and simplicity are as important as speed,” he said. “With this new system, firefighters can move faster by substituting many of the pieces of the process.”
For example, instead of mixing a salt solution for the firehoses, emergency workers can use seawater. Or workers can fill barriers with any available materials and filter the wastewater with clay, sand or dirt. The process is also simple enough for workers with limited training to build and maintain.
In laboratory tests at Argonne and demonstrations by the Denver and Columbus Fire Departments, the technique removed 70 to 100 percent of the radionuclides from hard surfaces. It also works on glass, metals and plastics, so it could be used to decontaminate aircraft, train cars and other vehicles.
Kaminski is continuing to refine the technique. “It has enormous potential because it cleans surfaces in minutes, not hours or days,” said Kaminski. “Another benefit is leveraging commonly available resources and materials.”
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