Perspectives for MUF at LEU fuel fabrication facility

At a facility handling nuclear material it is obliged to close the Material Balance Period (MBP) and establish the physical inventory in the facility once a year. The difference between the physical inventory and the theoretical inventory that is the figure on the book at the time of taking physical inventory is reported as the Inventory Difference or Material Unaccounted For (MUF). While this MUF is considered as an important indicator for judging the non-diversion and adequacy of the accounting system, it is controlled not to exceed the significant quantity. However since a diversion scenario exists related to the accumulated MUF arisen from the systematic bias that may be contained in the MUF, even if no diversion has been concluded for a single year MBP, it has been pointed out by IAEA to improve this point. In this report we sort out the parameters that may influence the MUF evaluation, then survey the points for improvements for reduction of MUF. Specifically the actions done at GNF-J for MUF reduction are presented and the problems to be solved in the future are also discussed. (author)