Spraying the special solution and cesium absorbent in a liquid state onto the surface of polluted materials such as cement turns it into a hydrogel coater.
(image: Korea Atomic Energy Research Institute)
SEOUL, Sept. 17 (Korea Bizwire) — A South Korean research team has developed new technology that can decontaminate the surface of radioactive polluted buildings simply by spraying a hydrogel-based spray coater and washing it with water.
The Korea Atomic Energy Research Institute announced on Wednesday that it had developed a hydrogel-based surface decontamination coater that can remove a pollutant (cesium-137, a highly radioactive material) simply by being sprayed onto the radioactive polluted surface.
Existing decontamination technology uses an exfoliation-type coater that needs to be peeled away or carved out after being applied to the surface of the polluted buildings.
This method has limits in its use since it’s difficult to go through the decontamination process rapidly, particularly when the surface to be decontaminated is large. It also leads to the generation of a huge amount of radioactive waste.
To develop the hydrogel-based decontamination coater, the research team mixed the special solution along with a cross-linking agent that connects high molecule chains with the cesium absorbent and the eco-friendly high molecule chemical polyvinyl alcohol.
Spraying the special solution and cesium absorbent in a liquid state onto the surface of polluted materials such as cement turns it into a hydrogel coater.
Cesium is detached from the surface after an ion exchange with the ammonium and sodium in the special solution and then attached onto the cesium absorbent.
When water is sprayed onto the cesium-absorbed hydrogel, the linkage structure of its high molecule chain is severed, turning the hydrogel back into liquid form and making it easy to remove.
The research team applied the hydrogel surface decontamination coater to concrete on the basis of the assumption that the buildings within a radius of 20 kilometers around the Fukushima nuclear power plant were contaminated with radiation.
The test showed that more than 57 percent of the cesium on the surface of the cement was removed, indicating that the decontamination performance of the hydrogel coater is more than two times stronger than existing exfoliation-type coaters.
J. S. Shin (js_shin@koreabizwire.com)
