Fissile Mass Flow Monitor Implementation for Transparency in HEU Blenddown at the Ural Electrochemical Integrated Plant (UEIP) in Novouralsk

The Oak Ridge National Laboratory (ORNL) Fissile Mass Flow Monitor (FMFM) was deployed at the Ural Electrochemical Integrated Plant (UEIP) highly enriched uranium (HEU) blending facility in January and February 1999 at Novouralsk in Russia for the DOE HEU Transparency Program. The FMFM provides unattended monitoring of the fissile mass flow of the uranium hexafluoride (UF low enriched uranium (LEU) blend stock, and the product LEU (P-LEU) of the blending tee non-intrusively. To do this, uranium- 235 (U-235) fissions are induced in the UF and modulated californium-252 (Cf-252) neutron source placed on each process line. A set of detectors, located downstream of source, measure delayed gamma rays emitted by the resulting fission fragments. The observed delay in the time correlated measurement between the source and the detector signal provides the velocity of UF U-235 content in UF modulator, processes the collected detector data, and displays the results. The UEIP Main and the Reserve process lines were implemented with minor modifications. The FMFM monitors the HEU blending operation by measuring UF process blending lines, and the traceability of the HEU flow from the blend point to the P-LEU. The detail operational characteristics of the FMFM software (FM2) and the measurement methodology used are presented. 6) gas in the process lines of HEU, the6 by a thermalized6 and its amplitude is related to the6. An on-line computer controls the source6 flows in the