The Research Institute of Atomic Reactors (RIAR) Experience with Material Consolidation and Conversion (MCC) of Excess Highly Enriched Uranium (HEU) Materials.

In 1999 RIAR (Research Institute of Atomic Reactors) started activity with Material Consolidation and Conversion (MCC) in collaboration with the U.S. Department of Energy (DOE) under a contract with the Brookhaven National Laboratory (BNL). The main objectives have been consolidation of excess Highly Enriched Uranium (HEU) materials with follow-up conversion to low enriched uranium (LEU - less than 20% U-235) oxide materials. Since the beginning of 2000 RIAR has consolidated and downblended over 900 kg of HEU (containing about 600 kg of U-235). The technical procedures for the preliminary HEU material preparation and monitoring procedures were developed. Some facilities were modified for preparation of HEU and downblending. New analytical equipment was installed with the support of DOE and new processes were developed for different HEU materials treatment. Additional equipment and process for treatment of U-Al HEU is under preparation now. Since 2002 the MCC activity has included conversion of HEU from other countries. The HEU fresh fuel at the Vinca Institute in Belgrade (Serbia) was repatriated to the Russian Federation. Also in 2003 fresh HEU fuel was consolidated from Bulgaria and in 2004 RIAR received the HEU from Libya. This activity was conducted under IAEA safeguards and supported by US DOS and DOE.