CALIBRATION OF SAFEGUARDS MONITORS USING THE URANYL NITRATE CALIBRATION LOOP EQUIPMENT (UNCLE) AT ORNL

The successful completion of a field trial of safeguards monitoring equipment at a natural uranium conversion plant (NUCP) demonstrated the need for a facility in which to perform full-scale equipment testing under controlled conditions prior to field deployment of safeguards systems at additional plants. Oak Ridge National Laboratory (ORNL) has developed the Uranyl Nitrate Calibration Loop Equipment (UNCLE) facility to simulate the full-scale operating conditions for a purified uranium-bearing aqueous stream exiting the solvent extraction process conducted in an NUCP. In addition to the calibration of detectors, such as the neutron detector developed at Los Alamos National Laboratory (LANL), UNCLE can be used to test other in-line instruments (mass and volumetric flowmeters, spectrophotometers, etc.), such as the Endress+Hauser Promass 83F Coriolis meter that was used in the field test. UNCLE was specifically designed to be process adaptable, enabling the variation of solution flow rates, solution concentrations, and other system properties of interest. The LANL neutron detector was installed at UNCLE in October 2008 to take background data during construction. Final construction of UNCLE was completed in June 2009, and the uranyl nitrate was added to the system the following month. The design and capabilities of UNCLE will be presented, along with test results to date.