Evaluation of Hydrogel Technologies for the Decontamination of ¹³⁷Cs From Building Material Surfaces

One of the preparation steps for a possible radiological attack is the capability of fast and effective decontamination of critical infrastructure. This study describes the implementation of a test plan at an intermediate scale (between bench scale and large scale or wide area) to evaluate decontamination procedures, materials, technologies, and techniques for removal of radioactive material from various surfaces. Two radioisotopes were tested: cesium-137 (¹³⁷Cs) and the short-lived simulant to ¹³⁷Cs, rubidium-86 (⁸⁶Rb). Two types of decontamination hydrogel products were evaluated: DeconGel™ and Argonne SuperGel. Tests were conducted at the assigned Chemical, Biological, Radiological, and Nuclear (CBRN) Israel Defense Forces (IDFs) Home Front Command facility, and at the Nuclear Research Center Negev (NRCN), Israel. Results from these tests indicated similar removal and operational parameters for ⁸⁶Rb and ¹³⁷Cs, as expected from the chemical similarity of both elements. These results proved that the short-lived radioisotope ⁸⁶Rb can be used in future experiments to simulate ¹³⁷Cs. Results and conclusions from these experiments are presented and compared to results from laboratory-scale experiments performed on small coupons. In general, both hydrogel decontamination products may be used as a viable option to decontaminate large surfaces in a real-world event, removing between 30% to 90% of the contamination, depending on the surface type and porosity. However, both products may leave behind absorbed contamination that will need to be addressed at a later stage. Yet, the likelihood of resuspension through use of these products is reduced.