TRANSFORMING THE URANYL NITRATE CALIBRATION LOOP EQUIPMENT (UNCLE) AT ORNL INTO A USER FACILITY

Oak Ridge National Laboratory (ORNL) has developed the Uranyl Nitrate Calibration Loop Equipment (UNCLE) facility, which currently simulates full-scale operating conditions for a purified uranium-bearing aqueous stream exiting the solvent extraction process in a natural uranium conversion plant (NUCP) operating at 6000 MTU/yr. The overall mission of the facility is to strengthen international safeguards concepts and approaches through the development and testing of safeguards instruments, whether they are commercial off the shelf or tailor made for a specific test. This facility is unique within the Department of Energy and can simulate conditions in an NUCP, an in situ leach mine, or a fuel fabrication plant for testing safeguards instrumentation. Policy Paper 18 (with anticipated successor Policy Paper 21) and recent International Atomic Energy Agency circulars suggest implementing safeguards when any purified aqueous uranium solution or uranium oxides exist, which are suitable for isotopic enrichment or fuel fabrication. UNCLE can easily adapt to new policies in response to dynamic proliferation and safeguards challenges. The design of UNCLE can accommodate several uranium-bearing solutions, various flow rates and solution concentrations, and other variables of interest. Recent upgrades to the facility include the installation of a heat pump with humidity control to ensure the environmental conditions in the facility remain constant. Additional upgrades are planned in 2012, which include new pipe segments for diversion studies and a solvent extraction system to remove decay products. These upgrades will allow the system to become a user facility at ORNL, where researchers from outside ORNL can test equipment at the facility. Currently UNCLE is being used for a comprehensive validation effort, which combines detector validation and source term modeling, to study the detection of diversion from declared activities. The design and capabilities of UNCLE will be presented, along with preliminary results from the validation effort and the new solvent extraction system. This work was supported by the Next Generation Safeguards Initiative (NGSI), Office of Nonproliferation and International Security (NIS), National Nuclear Security Administration (NNSA).