Safeguards Alternatives for a UREX+ Facility

This report reviews the design study of a complete, but conceptual, safeguards system for the UREX+ reprocessing plant. The incipient chemical design of the plant, on which this safeguards analysis is based, had been completed by Argonne National Laboratory. The intent of this safeguards study was to determine: • A design for an effective safeguards system predicated on the existing UREX+ process design. • Whether modest UREX+ plant design changes could improve safeguards effectiveness without a significant compromise of cost, operational effectiveness, or the underlying chemistry of the plant. The results of our investigations are: • An effective safeguards system can be implemented for this plant. A conceptual design of that system is presented here. However, an absolute determination of safeguards effectiveness requires a complete, detailed design and a diversion path analysis run against that design. • The extant UREX+ design has many features that actually aid the implementation of this safeguards system. The reason, in large measure, is that the present UREX+ process separates the spent fuel constituents to a higher degree than conventional reprocessing methods. This separation enables effective use of nondestructive assay (NDA) techniques more broadly than has been common. The general problem has been that spontaneous radiation from each radionuclide component in the dissolved spent fuel has interfered with the NDA measurement of other radionuclides. By separating the constituents to such a great extent, many of these NDA measurement interferences are removed. More general NDA techniques become possible, with low measurement error in many cases. These NDA methods provide the measurement basis for a more effective material control system. NDA instruments are operationally attractive in the high radiation environment of a reprocessing plant because they are more amenable to remote operation than the alternative, sampled measurements. In addition, NDA measurements do not create contamination as is common with sampled, Destructive Analysis (DA). NDA methods are also less expensive, typically, so they can be deployed more broadly. NDA methods provide results more quickly than DA, so that near real time analysis is possible. Finally, NDA systems generally measure the complete volume of a container (or at least a sizeable fraction of it) and are not as susceptible to sampling errors from the inhomogeneity of the sampled material.