Identification and Handling of Some Simple Covariance Effects in Material Balance Accounting

The material balance equation for Special Nuclear Material (SNM) yields a value for the Material Unaccounted For (MUF). The limit of error of MUF is usually calculated under the assumption of statistical independence for the components of the material balance. In this paper some of the simplest sources of covariance between the terms of'the MUF equation are identified and treated. The correlation between all components is a complex subject, and the complete resolution of covariance effects is beyond the scope of this paper.