Scientists in Germany and India are reporting development of a new cobalt imprinted polymer that reduces the amount of radioactive waste produced during routine operation of nuclear reactors. Their study, which details a first-of-its-kind discovery, has been published in Industrial&Engineering Chemistry Research.

Börje Sellergren and colleagues note that structural materials such as carbon steel in power plants' water cooling systems form deposits of metal oxides when they interact with coolants. In nuclear power plants, these oxides trap radioactive ions, leading to buildups of radioactivity that require costly cleanups of reactor surfaces. Cobalt, present in some alloys used in the reactors' water systems, is a major contributor toward this problem because of its long half-life.

Researchers have created a "smart" polymer that could decrease radioactive waste at nuclear power plants. Credit: Wikimedia Commons

In the study, the researchers created an adsorbent material that — unlike conventional ion-exchange resins that are frequently used in reactors — is selective for cobalt but has the unique ability of disregarding iron-based ions.

The retention capacity for the active cobalt was found to lessen reduction in the solution activity by about 55%.  The polymer's high selectivity increases its appeal, the researchers add, for use in decontamination processes in reactors that utilize a variety of structural materials.

ARTICLE: Anupkumar Bhaskarapillai, Narasimhan V. Sevilimedu, Brje Sellergren, "Synthesis and Characterization of Imprinted Polymers for Radioactive Waste Reduction", Ind. Eng. Chem. Res., 2009, 48 (8), pp 3730–3737 DOI: 10.1021/ie801640b