Method for manufacturing a radionuclide adsorbent, and a radioactive waste treatment device comprising the radionuclide adsorbent manufactured by said method

Radioactive waste shielding material using cesium-adsorbing carbonated cement paste from waste concrete

This technology involves extracting silicate-containing waste cement paste from the surface and interior of waste concrete, carbonating it by supplying carbon dioxide to produce a radionuclide adsorbent, and applying it to radioactive waste containers.

While construction waste accounts for over 60% of industrial waste, recycling of waste concrete has largely been limited to aggregate recovery, leaving the remaining cement paste underutilized. Meanwhile, materials used to adsorb radionuclides like cesium have been prohibitively expensive.

This technology produces an adsorbent containing calcium carbonate, silica gel, and alumina gel by subjecting the interior paste—which has a lower calcium carbonate content—to carbon dioxide under longer durations or higher temperature, pressure, and concentration. Higher silicate concentrations increase cesium adsorption. Applicable to nuclear decommissioning waste and radioactive waste storage container shielding, it simultaneously achieves construction waste recycling, carbon dioxide sequestration, and the prevention of radioactive material leakage.

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Key Features:

• Obtaining a first waste cement paste from the surface of waste concrete and a second waste cement paste from the interior, both containing silicate
• Carbonating the second waste cement paste by supplying carbon dioxide for a longer duration or at a higher temperature, pressure, or concentration than the first
• Washing the carbonated waste cement paste with acetone or isopropyl alcohol and drying it to obtain a radionuclide adsorbent
• A radioactive waste treatment device that applies the adsorbent to the exterior of a radioactive material storage container to adsorb dissolved cesium and provide external shielding

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This invention was developed with support from the Ministry of Science and ICT for research on improving the radionuclide immobilization and heat resistance of cementitious materials for geological disposal.

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