FEMO: A FLOW AND ENRICHMENT MONITOR FOR VERIFYING COMPLIANCE WITH INTERNATIONAL SAFEGUARDS REQUIREMENTS AT A GAS CENTRIFUGE ENRICHMENT FACILITY

摘要

A number of countries have received construction licenses or are contemplating the construction of large-capacity gas centrifuge enrichment plants (GCEPs). The capability to independently verify nuclear material flows is a key component of international safeguards approaches, and the International Atomic Energy Agency (IAEA) does not currently have an approved method to continuously monitor the mass flow of ~(235)U in uranium hexafluoride (UF_6) gas streams.rnOak Ridge National Laboratory and Los Alamos National Laboratory are jointly investigating the development of a flow and enrichment monitor (FEMO) based on an existing blend-down monitoring system (BDMS). The BDMS was designed to continuously monitor both ~(235)U mass flow and enrichment of UF_6 streams at the low pressures similar to those which exists at GCEPs. BDMSs have been installed at three sites-the first unit has operated successfully in an unattended environment for approximately 10 years. To be acceptable to GCEP operators, it is essential that the instrument be installed and maintained without interrupting operations.rnA means to continuously verify flow, as is proposed by FEMO, will probably be needed to contribute to safeguards at large-capacity plants. This system will enable the safeguards effectiveness that currently exists at smaller plants to be maintained at the larger facilities and also has the potential to reduce labor costs associated with inspections at current and future plants.rnThis paper describes the FEMO design requirements, operating capabilities, and development work required before a field demonstration.