UHEXRF Applications to the Nuclear Fuel Cycle

Ultrahigh energy X-ray fluorescence (UHEXRF) utilizes high energy excitation at 123 keV to directly detect and quantify uranium and plutonium through container walls. In this work the excitation beam of 123 keV is produced on the 6-ID-D beam line of the Advanced Photon Source at Argonne National Laboratory. This energy is sufficient to excite both the uranium K?1 and plutonium K?1 lines at 98.428 keV and 103.653 keV respectively. Several sample types have been measured with this approach including: dried spot residues of actual nuclear spent fuel and plutonium spiked synthetic spent fuel dried spot residues. In addition, a mock fuel rod containing model fuel pellets consisting of thorium oxide and uranium oxide with a stearic acid binder was also characterized. The thorium-uranium mixture provides a convenient model for the uranium-plutonium heavy metal ratio of actual spent fuel. The mock fuel rod used a typical Zircaloy tubing of around 600 micrometers thick. The Pu spiked standards were used to create a calibration of Pu intensity with known mass in the deposit to quantify the Pu in the spent fuel samples. UHEXRF has significant potential for nondestructive direct quantification of actinides through container walls. Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357. The authors would like to acknowledge the support of the DOE Defense Nuclear Nonproliferation R&D for financial support of this research effort.