Development of Gels for Decommissioning Applications

Abstract

During the decommissioning process, it is possible that contaminants could be generated in either vapour, liquid or solid phases that become separated from the parent material. Capturing these contaminants would reduce the generation of secondary, tertiary and/or further downstream wastes. One method of capturing loose contaminants is through the use of gels. There are many different types of gels that could potentially be used. Some are polymer based, others organic and even metallic compound based. Certain types of gels are excellent at absorbing water-based solutions. Furthermore, chemical additives can be combined with gels to enhance the capture/retention of certain contaminants. The gels can also have different levels of fluidity associated with them such as a hard puck like gel, a spongy gel, or a water like gel. Depending upon the type of constituent components used, the gels will behave differently, and have a different viscosity, which will affect how they can be used or manipulated in the capture process. It is also possible to transition from one type of consistency to another. For example, it may be beneficial to transition from a water type to that of a puck like consistency after the capture of contaminants. This work will examine different types of gels, their manufacturing process, and relevant process parameters that will affect their ability to be used in the field. The results indicate that gel mixing can be challenging and is a key step in the successful application of gels. Results also show that some types of gels do not necessarily retain their form and are prone to degradation. This suggests that their use is limited to short term applications and that further work may be necessary to secure the contaminants.