Monitoring of transuranic actinides (TRU–includes neptunium, plutonium, americium, and curium) during the separation of used nuclear fuel has been identified as a critical research area in the U.S. Advanced Fuel Cycle Research and Development program (AFC R&D). Recycling of used fuel by chemically separating it into uranium, fission products, and TRU would be the first step in this new fuel cyc...