Abstract
The Argonne SuperGel was developed between 2003 and 2015 to fill a gap in our nation’s capability to
quickly decontaminate important structures following a radiological or nuclear release event.
Specifically, the decontamination technology was developed to minimize damage to monuments, high
valued structures, and critical infrastructure while reducing environmental and health impacts. An
important criterion during its development, common reagents were employed that could be easily
acquired in order to minimize the timeline for its deployment. Its current formulation uses off-the-shelf
super-absorbing hydrogels common to the food and agricultural industry and common salts. Over the
years, two formulations of the Argonne SuperGel have been developed to specifically target radioactive
cesium contaminations and then, more generically, actinide and fission product contaminations. A
biodegradable derivative of phosphoric acid is used in small amounts to promote the removal of insoluble
actinide species
The original order of unit operations for the SuperGel technology was 1) applying the wash solution to
promote mobility of the contaminants on the surface, 2) applying the hydrogel to absorb the wash solution
and contaminants, and 3) removing the hydrogel for disposal. During the course of our studies, we tested
a new formulation of the gel technology that eliminated the need for a separate step to apply the wash
solution without a compromise in decontamination factors. Greater than 70% and >95% of Cs-137 were
removed from concrete and tile coupons, respectively, after two decontaminations, with the best results
using wash solutions of 1.0 M KCl and 1.0 M NH4Cl formulations. We found no statistical difference
between results at 30°C and 40°C or at 70% and 90% relative humidity. We tested the gel under strong
UV irradiation to simulate extreme environments. While a tropical noontime UV flux did not adversely
affect the gel system decontamination of Cs-137 from concrete or tile coupons, the noontime flux resulted
in significant dehydration of the gel after two hours of constant exposure. The rehydration of the gel by
the humid air (at 90% humidity and 40ºC) was slow and may not be sufficient to offset dehydration by the
sun. Americium decontamination from concrete was 70% after optimizing the phosphoric acid derivative
and carbonate salt concentration in the wash solution.
Worker applied the Argonne SuperGel to the coupons imbedded in a steel wall and removed the
hydrogel by wet-dry vacuum
Since its development, we have had the opportunity to test the SuperGel in the removal of legacy
contaminations in hot cell facilities and former glovebox facilities at Argonne. This has provided a
unique opportunity to evaluate the SuperGel on a range of contaminants outside the original specifications
for its use. We will report on the origin of the gel formulation, some highlighted experimental data
including independent testing by the US EPA which has never been reported, and its efficacy for
removing legacy alpha contaminations and its potential use for removal of chemical and biological
hazardous agents.