(258c) Radiation-Resistant Porous Materials for Capture and Separation of Volatile Radionuclides

Authors: 
Elsaidi, S. - Presenter, DOE National Energy and Technology Laboratory (NETL)
Mohamed, M., University of Pittsburgh
Helal, A., Massachusetts Institute of Technology
Hopkinson, D., National Energy Technology Laboratory
Thallapally, P. K., Pacific Northwest National Laboratory
Li, J., Massachusetts Institute of Technology
Pham, T., University of South Florida
Space, B., University of South Florida
Suepaul, S., University of South Florida
The release of volatile radionuclides, which must be captured and subsequently stored, is a major problem for the recycling of used nuclear fuel. Solid adsorbents, in particular ultra-microporous metal-organic frameworks (MOFs), could be efficient in capturing these volatile radionuclides, like 85Kr. However, MOFs are found to be more Xe-philic than Kr and to have a similar affinity between Kr and N2. In addition, the adsorbent needs to have good radiation stability. In order to overcome these challenges, we test a series of ultra-microporous MOFs, SIFSIX-3-M (M= Zn, Cu, Ni, Co or Fe) for their potential in 85Kr separation and storage using a two-bed breakthrough method. These materials were found to have higher Kr/N2 selectivity than the current benchmark materials, which lead to a notable decrease in the nuclear waste volume. The materials have been systematically studied for gamma and beta irradiation stability, which demonstrates that the metal centre in these isostructural frameworks plays a crucial role in their radiation resistance.