Year
1982
Abstract
Requirements for nuclear facility operators possessing strategic special nuclear material (SSNM) stress timely materials balances tests. The requirements often are written in such a way that a conservative false-alarm probability is left to the operator's resourcefulness. To accomplish a small false-alarm rate, uncertainties of estimated quantities must be reduced. If technology cannot improve the precision of estimated materials balances based on single measurements of the quantities of interest, precision can be improved by repeating the measurements. Central to the effectiveness of such a procedure is the fact that even small reductions in variance can sharply reduce the false-alarm rate. Formulas and tables are provided to illustrate the reduction of variance as a function of the number of repeated measurements for single and multiple materials control units. An example system of a typical facility is examined to show how the repeated measurement procedure can reduce the false-alarm probability.