Methods for monitoring target actinides in a fuel reprocessing or waste remediation facility. The methods can be characterized by providing a fuel reprocessing or waste remediation stream having at least one target actinide and at least one other radionuclide. At least a portion of the stream is flowed through an electrochemically modulated separations (EMS) device comprising a carbon-based electrode. A potential is applied to the carbon-based electrode to adjust the redox states of the target actinide, at least one of the radionuclides, or both. The target actinide is separated from the other radionuclides through reaction with, or at, the carbon-based electrode. Finally, direct, in-line chemical nondestructive analysis, at-line chemical separations and sampling analysis, or both, of the target actinide is performed.
SPONSORED RESEARCH AND DEVELOPMENT
 This invention was made with Government support under Contract DE-AC0576RL01830 awarded by the U.S. Department of Energy. The Government has certain rights in the invention.