Year
1985
Abstract
It is difficult to account for all the factors which can significantly affect the uncertainty of measurements of bulk inventories of special nuclear material. However, this paper presents a formula for estimating the \"variance\" of bulk inventory measurements which takes account of variability in several major contributors to inventory measurement uncertainty. These include concentration measurements, density measurements, manometer (liquid-level) readings and uncertainty in volume estimates resulting from the estimation of parameters in a linear (volume) calibration equation. This paper also describes a sampling experiment which was undertaken to obtain replicate measurements of density and concentration. Variance estimates for measurements of density and concentration obtained from a statistical analysis of the resulting data are reported. When these estimates of density and concentration measurement variance are used to evaluate the proposed variance formula for inventory measurements, the results compare favorably with those computed directly from replicate inventory measurements.