PNNL

Abstract

Used nuclear fuel (UNF) reprocessing represents a unique challenge when dealing with radionuclides such as isotopes of 85Kr and 129I2, due to their volatility and long half-life. However, efficient capture of 129I2 (t1/2 = 15.7 ×106 million years) from the nuclear waste stream can help to reduce the risk of releasing I2 radionuclide into the environment and mitigate concerns about human health problems. Metal organic frameworks (MOFs) have been reported to be potential I2 adsorbents: but the effect of water vapor, generally present in the reprocessing off-gas stream is rarely taken into account. Moisture stable porous MOFs, which can selectively adsorb I2 in presence of water vapor is thus of great interest. Herein, the I2 adsorption performance of two microporous MOFs is reported in presence of different humidity. I···•••phenyl ring interactions are mainly responsible for the adsorption as revealed by single crystal XRD