Concepts of Real Time and Semi-Real Time Material Control

The traditional approach to nuclear material control, or safeguards, involves the preparation of one or more closed material balances, each covering either a total facility or some major portion of a facility, called a material balance area (MBA). In principle, all components of the closed material balance are directly measured, such that the resulting material unaccounted for (MUF) consists only of the net result of measurement uncertainties plus any thefts or diversions. The uncertainties are assumed to be known on a probabilistic basis, thus permitting the detection of possible unaccountable losses (thefts or diversions) of significant magnitude.