NUMATIC, a Nuclear Material Data Error Analysis Code

NUMATIC (Nuclear Material Inventory Control) is a generic Monte-Carlo simulation tool that permits the modelling of facilities which process Special Nuclear Materials (SNM). Based on the number, location and quality of measurements made to quantify SNM masses within a user defined process, or number of inter-connected processes, the tool can (i) predict the inventory difference (ID) and its associated uncertainty (?ID) for any specified material balance area (MBA), (ii) determine, from the magnitude of the ID and associated uncertainty ?ID, the level of control exhibited over the SNM within the MBA, (iii) predict the required periodicity of SNM monitoring and/or process area clean-down operations in order to minimise the criticality threat posed by fissile material accumulation, and (iv) determine, through sensitivity analysis, those key measurements which heavily influence the level of SNM control. This ensures cost-effective targeting of measurement improvements. A description of the NUMATIC code will be given together with its designed role in improving fissile material control at the Atomic Weapons Establishment (AWE).